The document contains code and documentation for an abstract syntax tree (AST) implementation in C for a compiler project. It includes files for the AST node structure definition, symbol table implementation, lexer, parser, and Makefile. The lexer file specifies token definitions. The parser file defines grammar rules for parsing expressions, statements, functions and declarations to build the AST.
This document defines data structures and logic for a report that retrieves and displays customer payment information from various tables. It declares data types to store records from different tables, selects data into internal tables based on selection screen criteria, and builds a final table combining the records for display in an ALV grid. Event handling is defined to handle clicks on program names in the grid.
This document describes implementing a calculator using LEX and YACC. It includes code for calc.l which defines lexical rules and calc.y which defines syntactic rules for parsing integer and floating point expressions. The LEX file handles tokenization and the YACC file specifies a grammar for expressions and calculations along with handling evaluation and output. The resulting calculator can evaluate basic arithmetic expressions with integers and floats, and print results.
The document discusses various ways to extend and modify the Ruby parser. It covers:
1. Proposed syntax additions like {:key :-) "value"} and ++i which would require changes to the lexer and parser.
2. How the parser handles colons and symbols using token types like tCOLON2.
3. Examples of parsing constructs like method calls, assignments, and the def A#b syntax.
4. Details of how the lexer and parser are implemented in C using a parser generator and interaction between lexer states and token types.
The document provides an overview of the GIFT-VT tools framework. It describes the different levels and types of tools, the classes and inheritance used to implement tools, modules and services, how tools are executed by the server by loading the shared library and calling functions, and examples of tool configuration files and Makefiles.
The document discusses hacking the Ruby parser parse.y to add new syntax features to the Ruby language. It covers several cases:
1. Adding :-) as an alias for => in hash literals.
2. Treating single quotes as symbol literals under certain conditions.
3. Adding ++ as an incremental operator.
4. Parsing the A#b syntax for defining instance methods.
The document analyzes how parse.y and the lexer deal with colons, quotes, comments and other syntax elements, and shows the changes needed to parse the new syntax features. It also discusses Ruby internals like the parser generator bison, and MRI implementation details like the parse.y file size.
The document discusses the Falcon programming language, noting its open source, simple, fast and powerful nature. It highlights features of Falcon like full support for multithreading, support for coroutines, and faster speed compared to Python. Examples are provided of Falcon's syntax for variables, data types, operators, functions, and control flow structures that are similar to other languages like C/C++ and Lua.
Switch case statements can be used as a substitute for long if-else statements when comparing an integral value. The switch statement allows executing different blocks of code based on the value of a variable. It contains case labels that match values and an optional default case to handle unexpected values. Break statements are used to exit each case block and prevent falling through to the next block.
This document defines data structures and logic for a report that retrieves and displays customer payment information from various tables. It declares data types to store records from different tables, selects data into internal tables based on selection screen criteria, and builds a final table combining the records for display in an ALV grid. Event handling is defined to handle clicks on program names in the grid.
This document describes implementing a calculator using LEX and YACC. It includes code for calc.l which defines lexical rules and calc.y which defines syntactic rules for parsing integer and floating point expressions. The LEX file handles tokenization and the YACC file specifies a grammar for expressions and calculations along with handling evaluation and output. The resulting calculator can evaluate basic arithmetic expressions with integers and floats, and print results.
The document discusses various ways to extend and modify the Ruby parser. It covers:
1. Proposed syntax additions like {:key :-) "value"} and ++i which would require changes to the lexer and parser.
2. How the parser handles colons and symbols using token types like tCOLON2.
3. Examples of parsing constructs like method calls, assignments, and the def A#b syntax.
4. Details of how the lexer and parser are implemented in C using a parser generator and interaction between lexer states and token types.
The document provides an overview of the GIFT-VT tools framework. It describes the different levels and types of tools, the classes and inheritance used to implement tools, modules and services, how tools are executed by the server by loading the shared library and calling functions, and examples of tool configuration files and Makefiles.
The document discusses hacking the Ruby parser parse.y to add new syntax features to the Ruby language. It covers several cases:
1. Adding :-) as an alias for => in hash literals.
2. Treating single quotes as symbol literals under certain conditions.
3. Adding ++ as an incremental operator.
4. Parsing the A#b syntax for defining instance methods.
The document analyzes how parse.y and the lexer deal with colons, quotes, comments and other syntax elements, and shows the changes needed to parse the new syntax features. It also discusses Ruby internals like the parser generator bison, and MRI implementation details like the parse.y file size.
The document discusses the Falcon programming language, noting its open source, simple, fast and powerful nature. It highlights features of Falcon like full support for multithreading, support for coroutines, and faster speed compared to Python. Examples are provided of Falcon's syntax for variables, data types, operators, functions, and control flow structures that are similar to other languages like C/C++ and Lua.
Switch case statements can be used as a substitute for long if-else statements when comparing an integral value. The switch statement allows executing different blocks of code based on the value of a variable. It contains case labels that match values and an optional default case to handle unexpected values. Break statements are used to exit each case block and prevent falling through to the next block.
4 operators, expressions & statementsMomenMostafa
This document discusses various C programming language concepts including operators, expressions, statements, data types, and type conversions. It provides examples of using unary and binary operators, increment/decrement operators, and the modulus operator. It also discusses operator precedence, expressions, statements, and how C handles type conversions between integers, floats, and characters both automatically and through explicit casting. Loops and conditional statements are demonstrated in examples converting seconds to minutes and counting down bottles of water.
This document provides information on various data types in C programming language including integer, float, character and their properties. It discusses the size of basic data types using sizeof operator and size_t type. It also demonstrates the use of format specifiers in printf() statement to print values of different types and handles overflow, underflow cases. Code snippets are included to illustrate concepts around variable declaration, initialization, input-output using scanf() and printf().
The document discusses different types of selection and looping statements in C programming including if-else, if-else if-else, switch case, while loop, do-while loop, and for loop. It provides examples of each statement type and highlights important aspects like counter initialization, conditional expressions, and incrementing/decrementing counters. The differences between while, do-while and for loops are also summarized.
The document discusses various control structures in C++ like conditional statements (if-else, switch), loops (while, for, do-while), and jump statements (break, continue, goto). It provides examples to explain if-else, switch, while, for, do-while loops. Nested loops and break/continue statements are also covered. The last section briefly explains unconditional jump with goto statement.
The document provides an overview of PHP (Hypertext Preprocessor), a popular server-side scripting language. It discusses key PHP concepts like variables, data types, operators, forms, and functions. Some key points covered include:
- PHP code is embedded within <?php ?> tags and can output and interact with HTML
- PHP supports common variable types like integers, floats, strings, and arrays
- Operators allow performing tasks like math operations and comparisons on variables
- Forms allow user input and are submitted via GET or POST methods to PHP scripts
- Functions help organize and reuse code when called within a PHP program
COMP360 Assembler Write an assembler that reads the source code of an.pdffazalenterprises
COMP360 Assembler Write an assembler that reads the source code of an assembly program
(for an imaginary machine) and displays the machine language for that program. The following
assembler instructions must be supported. Instruction opcode Length Format Example add add
R1, R2, R3 sub R1, R2, R3 mult mult RI, R2, R3 I ld R1, addr R7) la R1, addr (RTT st R1, addr
R71 jump addr R71 R1, addr R71 3 push R1 Machine language instructions have the following
formats: 0: arithmetic Lopcode Reg I Reg 2 Reg3 4bits 4 bits 4 bits 1: Load, store. conditional
jump Dopcode eg index ad 4 bits 4 bits 4 bits 20 bits 2: call, jump de unused index addr 4 bits 4
bits 4 bits 20 bits 3: push, pop, lpsw. spsw opcode Reg 4 bits 4 bits 4: rtn opcode unused. 4 bits 4
bits
Solution
//First Create Package Collection then create all classes mentioned below
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package collection;
/**
*
* @author Rashmi Tiwari
*/
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Assembler {
public static final String COMP_ADD = \"ADD\";
public static final String COMP_SUB = \"SUB\";
public static final String COMP_LOAD = \"LOAD\";
public static final String COMP_STORE = \"STORE\";
public static final String COMP_GOTO = \"GOTO\";
public static final String COMP_GOTOZ = \"GOTOZ\";
public static final String COMP_GOTOP = \"GOTOP\";
public static final String COMP_READ = \"READ\";
public static final String COMP_WRITE = \"WRITE\";
public static final String COMP_STOP = \"STOP\";
private static Map assemblyTable;
private static Map getAssemblyTable() {
if (assemblyTable == null) {
assemblyTable = new HashMap();
assemblyTable.put(COMP_ADD, Comp360Assembler.COMP_ADD);
assemblyTable.put(COMP_SUB, Comp360Assembler.COMP_SUB);
assemblyTable.put(COMP_LOAD, Comp360Assembler.COMP_LOAD);
assemblyTable.put(COMP_STORE, Comp360Assembler.COMP_STORE);
assemblyTable.put(COMP_GOTO, Comp360Assembler.COMP_GOTO);
assemblyTable.put(COMP_GOTOZ, Comp360Assembler.COMP_GOTOZ);
assemblyTable.put(COMP_GOTOP, Comp360Assembler.COMP_GOTOP);
assemblyTable.put(COMP_READ, Comp360Assembler.COMP_READ);
assemblyTable.put(COMP_WRITE, Comp360Assembler.COMP_WRITE);
assemblyTable.put(COMP_STOP, Comp360Assembler.COMP_STOP);
}
return assemblyTable;
}
public static int[] assemble(String program) throws Comp360ParsingException {
if (program == null) return null;
program = preProcess(program);
Map symTable = buildSymTable(program);
return translateCommands(program, symTable);
}
public static String preProcess(String text) throws Comp360ParsingException {
text = text.replaceAll(\"(?ms)\\\\/\\\\*.*?\\\\*\\\\/\", \"\");
text = text.replaceAll(\"(?m)\\\\/\\\\/.*$\", \"\");
text = text.replaceAll(\"(?m)#.*$\", \"\");
text = text.replaceAll(\"(?m)\'.*$\", \"\");
text = text.replaceAll(\"(?m)`.*$\", \"\");
re.
This sample program demonstrates how to access Meinberg GPS receivers via the binary data protocol. It can work via a serial port or network socket connection depending on the target operating system. It requires several other modules and supports Windows, Linux, QNX, and DOS targets. The program checks return codes from API functions, gets receiver information, status information, position, time zone, and synthesizer settings. It also has the ability to set the synthesizer frequency and phase.
The document discusses adding a Struts Action class to a Struts portlet to display a maximized window state. It involves defining the action in struts-config.xml and tiles-defs.xml, creating JSP files, and an Action class to process the request. The Action class will return different JSPs depending on the window state in the request.
The document contains 7 programs written in C programming language. Program 1 recognizes tokens of control statements using finite state automata. Program 2 copies one file to another and counts comment lines. Program 3 counts lines, words, spaces and characters in a C file. Program 4 finds identifiers in a C file. Program 5 evaluates arithmetic expressions. Program 6 recognizes strings using grammar. Program 7 finds FIRST of NON-TERMINALS of a given grammar.
It is an attempt to make the students of IT understand the basics of programming in C in a simple and easy way. Send your feedback for rectification/further development.
You should be able to use the same function to check a narrowing fun.pdfsayandas941
You should be able to use the same function to check a narrowing function return by adding a
similar semantic action on the top level production for the whole function. Be sure that you have
declared that the function_header and body productions carry a type attribute if your receive an
error indicating that they have no declared type. In addition both require semantic actions that
pass the type information up the parse tree.
My issue is that my output says "Type Mismatch on Function Body" when it should say "Illegal
Narrowing Function Return"
heres the test case:
-- Narrowing Function Return
function main returns integer;
b: integer is 6 * 2;
begin
if 8 < 0 then
b + 3.0;
else
b * 4.6;
endif;
end;
heres the expected output:
--Narrowing Function Return
function main returns integer;
b: integer is 6 * 2;
begin
if 8 < 0 then
b + 3.0;
else
b * 4.6;
endif;
end;
Semantic Error, Illegal Narrowing Function Return
Lexical Errors 0
Syntax Errors 0
Semantic Errors 1
Heres the output I'm getting:
-- Narrowing Function Return
function main returns integer;
b: integer is 6 * 2;
begin
if 8 < 0 then
b + 3.0;
else
b * 4.6;
endif;
end;
Semantic Error, Type Mismatch on Function Body
Lexical Errors: 0
Syntax Errors: 0
Semantic Errors 1
heres my parser.y code:
/* Compiler Theory and Design
Duane J. Jarc */
%{
#include
#include
#include
#include
#include
using namespace std;
#include "types.h"
#include "listing.h"
#include "symbols.h"
int yylex();
void yyerror(const char* message);
Symbols symbols;
Types case_return = INT_TYPE;
Types current_function_return = INT_TYPE;
%}
%define parse.error verbose
%union
{
CharPtr iden;
Types type;
}
%token IDENTIFIER
%token INT_LITERAL REAL_LITERAL BOOL_LITERAL CASE ELSE IF ENDIF
%token ADDOP MULOP RELOP ANDOP EXPOP REMOP OROP NOTOP
%token BEGIN_ BOOLEAN END ENDREDUCE FUNCTION INTEGER IS REDUCE
RETURNS
%token ENDCASE OTHERS REAL ARROW THEN WHEN
%type type statement_ statement variable parameter reductions expression binary
relation term factor exponent unary primary case cases
%type function
%type function_header
%type body
%%
function:
function_header optional_variable body ;
function_header:
FUNCTION IDENTIFIER parameters RETURNS type {
current_function_return = $5;
checkAssignment($5, $1, "Function Return"); // Check for illegal narrowing
} ';' |
FUNCTION IDENTIFIER RETURNS type {
current_function_return = $3;
checkAssignment($3, $1, "Function Return"); // Check for illegal narrowing
} ';' |
error ';' {
$$ = MISMATCH;
};
optional_variable:
optional_variable variable | %empty
;
variable:
IDENTIFIER ':' type IS statement_
{checkAssignment($3, $5, "Variable Initialization");
if (symbols.find($1, $3))
appendError(DUPLICATE_IDENTIFIER, $1);
else
symbols.insert($1, $3);} |
error ';' {$$ = MISMATCH;};
parameters:
parameter optional_parameter;
optional_parameter:
optional_parameter ',' parameter | %empty
;
parameter:
IDENTIFIER ':' type {
if(symbols.find($1, $$))
appendError(DUPLICATE_IDENTIFIER, $1);
else
symbols.insert($1, $3);} |.
The document discusses syntax analysis and creating parsers using Yacc/Bison. It provides examples of writing grammars and semantic actions for simple arithmetic expressions. Key points covered include:
- Yacc/Bison generate LALR(1) parsers from grammar specifications
- A Yacc specification contains declarations, translation rules (productions with semantic actions), and auxiliary C functions
- Productions define the grammar, semantic actions associate values with terminals/nonterminals
- Attributes refer to semantic values, precedence levels resolve ambiguity
- Lex/Flex is used to generate a lexical analyzer from regular expressions to interface with the parser
Type hints were introduced with PHP 5. PHP 7 will add the ability to type hint on scalars and even to explicitly state what type will be returned from the function. This talk briefly goes over these added features to PHP 7.
1. The documents describe C programs that implement stacks using arrays, evaluate postfix expressions, convert infix to postfix notation, and check for balanced parentheses.
2. Key aspects include using structures to represent stacks, functions for push, pop, empty, full, and display operations on stacks.
3. The programs demonstrate using stacks to evaluate expressions by pushing operands and applying operators based on precedence.
The document discusses functions in PHP, including defining functions, passing arguments to functions, returning values from functions, and using global variables. Some key points covered include:
- Functions allow code to be reused and separated into logical subsections, making code more modular, readable, and maintainable.
- Arguments passed to functions can make functions more flexible by allowing different inputs to produce different outputs each time they are called.
- Functions can return values to the calling code using the return statement. Returned values can be variables, arrays, or results of calculations.
- The order arguments are passed to a function matters, as arguments are assigned to placeholder variables in the defined order. Default values can be specified for arguments.
This document contains PHP code for a web shell that provides various functions like file management, command execution, database operations etc. It starts a session, sets time limit and error reporting to 0. It then strips slashes from GET/POST/COOKIE variables. The rest of the code handles different requests like file upload, download, rename, delete etc and displays menus to call these functions. It also shows server information and has about page.
The document discusses functions in C programming. It provides examples of function declarations, definitions, calls, parameters, return values, return types, and different categories of functions. It also discusses scope and lifetime of variables, storage classes, function calls and recursion, and preprocessor directives.
The document discusses functions in C programming. It defines what a function is, how functions are declared and defined, different types of functions based on return values and parameters, and how functions are called and executed. It also covers function scope, lifetime, and storage classes. Preprocessor directives are also briefly explained.
This document contains source code for an online quiz system created by Sushil Kumar Mishra of ECE-I. It includes classes for drawing lines and boxes, managing menus, and controlling quiz functions like adding, deleting, and modifying questions in different subject databases. The main menu allows users to play quizzes, add questions, edit questions, or quit. Playing a quiz displays questions one by one with a time limit to select the correct answer. Scores are tracked and displayed at the end.
Melissa HinkhouseWeek 3-Original PostNURS 6050 Policy and A.docxwkyra78
Melissa Hinkhouse
Week 3-Original Post
NURS 6050: Policy and Advocacy for Improving Population Health
Walden University
In 2010 The Affordable Care Act (ACA) was enacted; the hope was to expand access to medical care, make coverage more affordable, and decrease the number of people without medical insurance. The Affordable Care Act (ACA) expanded and improved health insurance coverage in two primary ways. First, the number of individuals receiving insurance coverage grown by increasing access to coverage through Medicaid expansion and providing subsidies to purchase private insurance on the health care exchanges. Second, the ACA upgraded the quality and scope of coverage by improving benefit design, including implementing the essential health benefits (Willison & Singer, 2017). People who did not have coverage through their employer or Medicaid were required to purchase insurance through the Marketplace. The Marketplace was created as a one-stop-shop for people to view multiple plans and purchase insurance. Just because you have access to health care insurance does not mean you are going to receive quality health care (Teitelbaum, 2018).
Both parties have asked that the ACA be repealed or replaced for multiple reasons. Every Republican presidential candidate for 2016 has called for the repeal of the ACA. Some, but not all, Republican candidates have proposed health policies that they would like to put in place after repeal, but there is no broad agreement on a replacement for the ACA (Buettgens & Blumberg, 2016). The federal government would spend $90.9 billion less on health care for the nonelderly in 2021 if the ACA were repealed (Buettgens & Blumberg, 2016). State governments as a whole would spend $5.2 billion more on health care for the nonelderly in 2021 if the ACA were repealed (Buettgens & Blumberg, 2016). Healthcare is a priority to many Americans for obvious reasons; it was more costly for those with preexisting conditions before the ACA to obtain Medical Insurance. With the ACA the income guidelines for Medicaid where changed so additional people qualified that didn’t prior. As a Behavioral Health Nurse, I am a fan of anyone and everyone having access to Healthcare Services. I have seen to many times my patient not have the money for their medications because insurance was canceled so they go off their medications, they become unstable and ended up in the Emergency Department and admitted Inpatient, costing more money, hurting themselves and their loved ones.
Politicians are aware that election time is the best time to play the tug of war game with the heavy ticket items to capture someone votes. Republicans ran hard on promises to get rid of the law in every election since it passed in 2010. But when the GOP finally got control of the House, the Senate and the White House in 2017, Republicans found
they could not reach agreement
on how to "repeal and replace" the law (Kaiser Health News, 2018). And political strategists s.
Melissa Hinkhouse
Advanced Pharmacology NURS-6521N-43
Professor Dr. Vicki Gardin
Discussion Board Week 1-Original Post
11/30/2020
I have worked in an outpatient behavioral health clinic for the past seven years with many different providers. I live in a rural community, many patients wait six to twelve months to be seen. Patients being treated for Attention Deficit Disorder must be officially tested before being seen by a Psychologist. For this discussion board post, I have changed the name of my patient to Paul to ensure patient confidentially. The provider I worked with this particular patient will also be referred to as PMHNP to ensure provider confidentiality.
Paul was a ten-year-old Caucasian male referred to our clinic diagnosed per DSM criteria, confirmed via Psychologist testing with ADHD. When he saw the Psychologist, he was also diagnosed with mild depression and anxiety. He struggled with concentration, hyperactivity, impulse control, and disorganization. He presented to his appointment with his mother and father, clean, well-nourished, pleasant, interactive with staff, reported no medication allergies, current medication Zyrtec for seasonal allergies. Paul just had his well-child exam and is current on vaccinations and his primary care provider completed lab work to include CBC, CMP, TSH, Vit D, B12, and A1C, all have returned normal. Family history reported father has a history of ADHD (never medicated), brother has a history of depression and anxiety (never medicated treating with psychotherapy), no other significant family history to report. Paul’s current weight at his appointment was 30kg.
PMHNP spent one hour with Paul and his parents for the initial new patient appointment (Thursday). It was decided Paul would be prescribed Strattera (atomoxetine) 40mg once a day for one week then increase to 80mg once a day. I returned to work on Monday and received a call from Paul’s mom, she said he was acting strange. He was tearful, had been in his room with the door closed for most of the weekend, she stated on Sunday she went into his room and he was crying and said he was just thinking about dying and his parents dying. She stated he had already had his meds Sunday so she kept him with her that entire day and made Sunday night a campout night in the Livingroom so he would think it was fun and she could keep a close eye on him. I had a cancelation that morning for him to come to see PMHNP and he was in to see her within twenty minutes and removed from Strattera. His parents decided medications were no longer the route they wanted to try for treatment and a referral was made for psychotherapy.
The only medication Paul takes on occasion is Zyrtec which is in an antihistamine drug class, Strattera is a selective norepinephrine reuptake inhibitor; there is no known drug interaction between the two medications. Reflecting on his age and the medication, Strattera has a black box labeled for suicidal ideation with adolescents dia.
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Similar to project4-ast.DS_Storeproject4-astast.c#include symbolTa.docx
4 operators, expressions & statementsMomenMostafa
This document discusses various C programming language concepts including operators, expressions, statements, data types, and type conversions. It provides examples of using unary and binary operators, increment/decrement operators, and the modulus operator. It also discusses operator precedence, expressions, statements, and how C handles type conversions between integers, floats, and characters both automatically and through explicit casting. Loops and conditional statements are demonstrated in examples converting seconds to minutes and counting down bottles of water.
This document provides information on various data types in C programming language including integer, float, character and their properties. It discusses the size of basic data types using sizeof operator and size_t type. It also demonstrates the use of format specifiers in printf() statement to print values of different types and handles overflow, underflow cases. Code snippets are included to illustrate concepts around variable declaration, initialization, input-output using scanf() and printf().
The document discusses different types of selection and looping statements in C programming including if-else, if-else if-else, switch case, while loop, do-while loop, and for loop. It provides examples of each statement type and highlights important aspects like counter initialization, conditional expressions, and incrementing/decrementing counters. The differences between while, do-while and for loops are also summarized.
The document discusses various control structures in C++ like conditional statements (if-else, switch), loops (while, for, do-while), and jump statements (break, continue, goto). It provides examples to explain if-else, switch, while, for, do-while loops. Nested loops and break/continue statements are also covered. The last section briefly explains unconditional jump with goto statement.
The document provides an overview of PHP (Hypertext Preprocessor), a popular server-side scripting language. It discusses key PHP concepts like variables, data types, operators, forms, and functions. Some key points covered include:
- PHP code is embedded within <?php ?> tags and can output and interact with HTML
- PHP supports common variable types like integers, floats, strings, and arrays
- Operators allow performing tasks like math operations and comparisons on variables
- Forms allow user input and are submitted via GET or POST methods to PHP scripts
- Functions help organize and reuse code when called within a PHP program
COMP360 Assembler Write an assembler that reads the source code of an.pdffazalenterprises
COMP360 Assembler Write an assembler that reads the source code of an assembly program
(for an imaginary machine) and displays the machine language for that program. The following
assembler instructions must be supported. Instruction opcode Length Format Example add add
R1, R2, R3 sub R1, R2, R3 mult mult RI, R2, R3 I ld R1, addr R7) la R1, addr (RTT st R1, addr
R71 jump addr R71 R1, addr R71 3 push R1 Machine language instructions have the following
formats: 0: arithmetic Lopcode Reg I Reg 2 Reg3 4bits 4 bits 4 bits 1: Load, store. conditional
jump Dopcode eg index ad 4 bits 4 bits 4 bits 20 bits 2: call, jump de unused index addr 4 bits 4
bits 4 bits 20 bits 3: push, pop, lpsw. spsw opcode Reg 4 bits 4 bits 4: rtn opcode unused. 4 bits 4
bits
Solution
//First Create Package Collection then create all classes mentioned below
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
package collection;
/**
*
* @author Rashmi Tiwari
*/
import java.util.ArrayList;
import java.util.HashMap;
import java.util.Map;
import java.util.Scanner;
public class Assembler {
public static final String COMP_ADD = \"ADD\";
public static final String COMP_SUB = \"SUB\";
public static final String COMP_LOAD = \"LOAD\";
public static final String COMP_STORE = \"STORE\";
public static final String COMP_GOTO = \"GOTO\";
public static final String COMP_GOTOZ = \"GOTOZ\";
public static final String COMP_GOTOP = \"GOTOP\";
public static final String COMP_READ = \"READ\";
public static final String COMP_WRITE = \"WRITE\";
public static final String COMP_STOP = \"STOP\";
private static Map assemblyTable;
private static Map getAssemblyTable() {
if (assemblyTable == null) {
assemblyTable = new HashMap();
assemblyTable.put(COMP_ADD, Comp360Assembler.COMP_ADD);
assemblyTable.put(COMP_SUB, Comp360Assembler.COMP_SUB);
assemblyTable.put(COMP_LOAD, Comp360Assembler.COMP_LOAD);
assemblyTable.put(COMP_STORE, Comp360Assembler.COMP_STORE);
assemblyTable.put(COMP_GOTO, Comp360Assembler.COMP_GOTO);
assemblyTable.put(COMP_GOTOZ, Comp360Assembler.COMP_GOTOZ);
assemblyTable.put(COMP_GOTOP, Comp360Assembler.COMP_GOTOP);
assemblyTable.put(COMP_READ, Comp360Assembler.COMP_READ);
assemblyTable.put(COMP_WRITE, Comp360Assembler.COMP_WRITE);
assemblyTable.put(COMP_STOP, Comp360Assembler.COMP_STOP);
}
return assemblyTable;
}
public static int[] assemble(String program) throws Comp360ParsingException {
if (program == null) return null;
program = preProcess(program);
Map symTable = buildSymTable(program);
return translateCommands(program, symTable);
}
public static String preProcess(String text) throws Comp360ParsingException {
text = text.replaceAll(\"(?ms)\\\\/\\\\*.*?\\\\*\\\\/\", \"\");
text = text.replaceAll(\"(?m)\\\\/\\\\/.*$\", \"\");
text = text.replaceAll(\"(?m)#.*$\", \"\");
text = text.replaceAll(\"(?m)\'.*$\", \"\");
text = text.replaceAll(\"(?m)`.*$\", \"\");
re.
This sample program demonstrates how to access Meinberg GPS receivers via the binary data protocol. It can work via a serial port or network socket connection depending on the target operating system. It requires several other modules and supports Windows, Linux, QNX, and DOS targets. The program checks return codes from API functions, gets receiver information, status information, position, time zone, and synthesizer settings. It also has the ability to set the synthesizer frequency and phase.
The document discusses adding a Struts Action class to a Struts portlet to display a maximized window state. It involves defining the action in struts-config.xml and tiles-defs.xml, creating JSP files, and an Action class to process the request. The Action class will return different JSPs depending on the window state in the request.
The document contains 7 programs written in C programming language. Program 1 recognizes tokens of control statements using finite state automata. Program 2 copies one file to another and counts comment lines. Program 3 counts lines, words, spaces and characters in a C file. Program 4 finds identifiers in a C file. Program 5 evaluates arithmetic expressions. Program 6 recognizes strings using grammar. Program 7 finds FIRST of NON-TERMINALS of a given grammar.
It is an attempt to make the students of IT understand the basics of programming in C in a simple and easy way. Send your feedback for rectification/further development.
You should be able to use the same function to check a narrowing fun.pdfsayandas941
You should be able to use the same function to check a narrowing function return by adding a
similar semantic action on the top level production for the whole function. Be sure that you have
declared that the function_header and body productions carry a type attribute if your receive an
error indicating that they have no declared type. In addition both require semantic actions that
pass the type information up the parse tree.
My issue is that my output says "Type Mismatch on Function Body" when it should say "Illegal
Narrowing Function Return"
heres the test case:
-- Narrowing Function Return
function main returns integer;
b: integer is 6 * 2;
begin
if 8 < 0 then
b + 3.0;
else
b * 4.6;
endif;
end;
heres the expected output:
--Narrowing Function Return
function main returns integer;
b: integer is 6 * 2;
begin
if 8 < 0 then
b + 3.0;
else
b * 4.6;
endif;
end;
Semantic Error, Illegal Narrowing Function Return
Lexical Errors 0
Syntax Errors 0
Semantic Errors 1
Heres the output I'm getting:
-- Narrowing Function Return
function main returns integer;
b: integer is 6 * 2;
begin
if 8 < 0 then
b + 3.0;
else
b * 4.6;
endif;
end;
Semantic Error, Type Mismatch on Function Body
Lexical Errors: 0
Syntax Errors: 0
Semantic Errors 1
heres my parser.y code:
/* Compiler Theory and Design
Duane J. Jarc */
%{
#include
#include
#include
#include
#include
using namespace std;
#include "types.h"
#include "listing.h"
#include "symbols.h"
int yylex();
void yyerror(const char* message);
Symbols symbols;
Types case_return = INT_TYPE;
Types current_function_return = INT_TYPE;
%}
%define parse.error verbose
%union
{
CharPtr iden;
Types type;
}
%token IDENTIFIER
%token INT_LITERAL REAL_LITERAL BOOL_LITERAL CASE ELSE IF ENDIF
%token ADDOP MULOP RELOP ANDOP EXPOP REMOP OROP NOTOP
%token BEGIN_ BOOLEAN END ENDREDUCE FUNCTION INTEGER IS REDUCE
RETURNS
%token ENDCASE OTHERS REAL ARROW THEN WHEN
%type type statement_ statement variable parameter reductions expression binary
relation term factor exponent unary primary case cases
%type function
%type function_header
%type body
%%
function:
function_header optional_variable body ;
function_header:
FUNCTION IDENTIFIER parameters RETURNS type {
current_function_return = $5;
checkAssignment($5, $1, "Function Return"); // Check for illegal narrowing
} ';' |
FUNCTION IDENTIFIER RETURNS type {
current_function_return = $3;
checkAssignment($3, $1, "Function Return"); // Check for illegal narrowing
} ';' |
error ';' {
$$ = MISMATCH;
};
optional_variable:
optional_variable variable | %empty
;
variable:
IDENTIFIER ':' type IS statement_
{checkAssignment($3, $5, "Variable Initialization");
if (symbols.find($1, $3))
appendError(DUPLICATE_IDENTIFIER, $1);
else
symbols.insert($1, $3);} |
error ';' {$$ = MISMATCH;};
parameters:
parameter optional_parameter;
optional_parameter:
optional_parameter ',' parameter | %empty
;
parameter:
IDENTIFIER ':' type {
if(symbols.find($1, $$))
appendError(DUPLICATE_IDENTIFIER, $1);
else
symbols.insert($1, $3);} |.
The document discusses syntax analysis and creating parsers using Yacc/Bison. It provides examples of writing grammars and semantic actions for simple arithmetic expressions. Key points covered include:
- Yacc/Bison generate LALR(1) parsers from grammar specifications
- A Yacc specification contains declarations, translation rules (productions with semantic actions), and auxiliary C functions
- Productions define the grammar, semantic actions associate values with terminals/nonterminals
- Attributes refer to semantic values, precedence levels resolve ambiguity
- Lex/Flex is used to generate a lexical analyzer from regular expressions to interface with the parser
Type hints were introduced with PHP 5. PHP 7 will add the ability to type hint on scalars and even to explicitly state what type will be returned from the function. This talk briefly goes over these added features to PHP 7.
1. The documents describe C programs that implement stacks using arrays, evaluate postfix expressions, convert infix to postfix notation, and check for balanced parentheses.
2. Key aspects include using structures to represent stacks, functions for push, pop, empty, full, and display operations on stacks.
3. The programs demonstrate using stacks to evaluate expressions by pushing operands and applying operators based on precedence.
The document discusses functions in PHP, including defining functions, passing arguments to functions, returning values from functions, and using global variables. Some key points covered include:
- Functions allow code to be reused and separated into logical subsections, making code more modular, readable, and maintainable.
- Arguments passed to functions can make functions more flexible by allowing different inputs to produce different outputs each time they are called.
- Functions can return values to the calling code using the return statement. Returned values can be variables, arrays, or results of calculations.
- The order arguments are passed to a function matters, as arguments are assigned to placeholder variables in the defined order. Default values can be specified for arguments.
This document contains PHP code for a web shell that provides various functions like file management, command execution, database operations etc. It starts a session, sets time limit and error reporting to 0. It then strips slashes from GET/POST/COOKIE variables. The rest of the code handles different requests like file upload, download, rename, delete etc and displays menus to call these functions. It also shows server information and has about page.
The document discusses functions in C programming. It provides examples of function declarations, definitions, calls, parameters, return values, return types, and different categories of functions. It also discusses scope and lifetime of variables, storage classes, function calls and recursion, and preprocessor directives.
The document discusses functions in C programming. It defines what a function is, how functions are declared and defined, different types of functions based on return values and parameters, and how functions are called and executed. It also covers function scope, lifetime, and storage classes. Preprocessor directives are also briefly explained.
This document contains source code for an online quiz system created by Sushil Kumar Mishra of ECE-I. It includes classes for drawing lines and boxes, managing menus, and controlling quiz functions like adding, deleting, and modifying questions in different subject databases. The main menu allows users to play quizzes, add questions, edit questions, or quit. Playing a quiz displays questions one by one with a time limit to select the correct answer. Scores are tracked and displayed at the end.
Similar to project4-ast.DS_Storeproject4-astast.c#include symbolTa.docx (20)
Melissa HinkhouseWeek 3-Original PostNURS 6050 Policy and A.docxwkyra78
Melissa Hinkhouse
Week 3-Original Post
NURS 6050: Policy and Advocacy for Improving Population Health
Walden University
In 2010 The Affordable Care Act (ACA) was enacted; the hope was to expand access to medical care, make coverage more affordable, and decrease the number of people without medical insurance. The Affordable Care Act (ACA) expanded and improved health insurance coverage in two primary ways. First, the number of individuals receiving insurance coverage grown by increasing access to coverage through Medicaid expansion and providing subsidies to purchase private insurance on the health care exchanges. Second, the ACA upgraded the quality and scope of coverage by improving benefit design, including implementing the essential health benefits (Willison & Singer, 2017). People who did not have coverage through their employer or Medicaid were required to purchase insurance through the Marketplace. The Marketplace was created as a one-stop-shop for people to view multiple plans and purchase insurance. Just because you have access to health care insurance does not mean you are going to receive quality health care (Teitelbaum, 2018).
Both parties have asked that the ACA be repealed or replaced for multiple reasons. Every Republican presidential candidate for 2016 has called for the repeal of the ACA. Some, but not all, Republican candidates have proposed health policies that they would like to put in place after repeal, but there is no broad agreement on a replacement for the ACA (Buettgens & Blumberg, 2016). The federal government would spend $90.9 billion less on health care for the nonelderly in 2021 if the ACA were repealed (Buettgens & Blumberg, 2016). State governments as a whole would spend $5.2 billion more on health care for the nonelderly in 2021 if the ACA were repealed (Buettgens & Blumberg, 2016). Healthcare is a priority to many Americans for obvious reasons; it was more costly for those with preexisting conditions before the ACA to obtain Medical Insurance. With the ACA the income guidelines for Medicaid where changed so additional people qualified that didn’t prior. As a Behavioral Health Nurse, I am a fan of anyone and everyone having access to Healthcare Services. I have seen to many times my patient not have the money for their medications because insurance was canceled so they go off their medications, they become unstable and ended up in the Emergency Department and admitted Inpatient, costing more money, hurting themselves and their loved ones.
Politicians are aware that election time is the best time to play the tug of war game with the heavy ticket items to capture someone votes. Republicans ran hard on promises to get rid of the law in every election since it passed in 2010. But when the GOP finally got control of the House, the Senate and the White House in 2017, Republicans found
they could not reach agreement
on how to "repeal and replace" the law (Kaiser Health News, 2018). And political strategists s.
Melissa Hinkhouse
Advanced Pharmacology NURS-6521N-43
Professor Dr. Vicki Gardin
Discussion Board Week 1-Original Post
11/30/2020
I have worked in an outpatient behavioral health clinic for the past seven years with many different providers. I live in a rural community, many patients wait six to twelve months to be seen. Patients being treated for Attention Deficit Disorder must be officially tested before being seen by a Psychologist. For this discussion board post, I have changed the name of my patient to Paul to ensure patient confidentially. The provider I worked with this particular patient will also be referred to as PMHNP to ensure provider confidentiality.
Paul was a ten-year-old Caucasian male referred to our clinic diagnosed per DSM criteria, confirmed via Psychologist testing with ADHD. When he saw the Psychologist, he was also diagnosed with mild depression and anxiety. He struggled with concentration, hyperactivity, impulse control, and disorganization. He presented to his appointment with his mother and father, clean, well-nourished, pleasant, interactive with staff, reported no medication allergies, current medication Zyrtec for seasonal allergies. Paul just had his well-child exam and is current on vaccinations and his primary care provider completed lab work to include CBC, CMP, TSH, Vit D, B12, and A1C, all have returned normal. Family history reported father has a history of ADHD (never medicated), brother has a history of depression and anxiety (never medicated treating with psychotherapy), no other significant family history to report. Paul’s current weight at his appointment was 30kg.
PMHNP spent one hour with Paul and his parents for the initial new patient appointment (Thursday). It was decided Paul would be prescribed Strattera (atomoxetine) 40mg once a day for one week then increase to 80mg once a day. I returned to work on Monday and received a call from Paul’s mom, she said he was acting strange. He was tearful, had been in his room with the door closed for most of the weekend, she stated on Sunday she went into his room and he was crying and said he was just thinking about dying and his parents dying. She stated he had already had his meds Sunday so she kept him with her that entire day and made Sunday night a campout night in the Livingroom so he would think it was fun and she could keep a close eye on him. I had a cancelation that morning for him to come to see PMHNP and he was in to see her within twenty minutes and removed from Strattera. His parents decided medications were no longer the route they wanted to try for treatment and a referral was made for psychotherapy.
The only medication Paul takes on occasion is Zyrtec which is in an antihistamine drug class, Strattera is a selective norepinephrine reuptake inhibitor; there is no known drug interaction between the two medications. Reflecting on his age and the medication, Strattera has a black box labeled for suicidal ideation with adolescents dia.
Meiner, S. E., & Yeager, J. J. (2019). Chapter 17Chap.docxwkyra78
Meiner, S. E., & Yeager, J. J. (2019).
Chapter 17
Chapter_017.pptx
Chapter 18
Chapter_018.pptx
Chapter 19
Chapter_019.pptx
Chapter 20
Chapter_020.pptx
Watch
None.
Supplemental Materials & Resources
Visit the
CINAHL Complete
under the
A-to-Z Databases
on the
University Library's
website and locate the article(s) below:
O’Keefe-McCarthy, S. (2009). Technologically-mediated nursing care: The impact on moral agency. Nursing Ethics, 16(6), 76-796.
Teutsch, S., & Rechel, B. (2012). Ethics of resource allocation and rationing medical care in a time of fiscal restraint: US and Europe. Public Health Reviews, 34(1), 1-10.
QUESTION
Define presbycusis, name signs and symptoms, etiology and differential diagnosis.
Create 3 interventions-education measures with a patient with Presbycusis.
List, define and elaborate on three different retinal and macular diseases age-related.
Submission Instructions:
Your initial post should be at least 500 words, formatted and cited in current APA style with support from at least 2 academic sources
Your assignment will be graded according to the grading rubric.
.
member is a security software architect in a cloud service provider .docxwkyra78
member is a security software architect in a cloud service provider company, assigned to a project to provide the client with data integrity and confidentiality protections for data in transit that will be using applications in the cloud. Your client is an HR company that is moving HR applications and HR data into a community cloud, sharing tenancy with other clients. Your company has set up a software as a service, SAS, offering for its client base.
The data that the HR company will be pushing to and from the cloud will contain sensitive employee information, such as personally identifiable information, PII. You will have to address sensitive data and transit issues of the client data using the HR applications stored in the cloud, and provide a life cycle management report that includes solutions to the cloud computing architect of your company.
Software Development Life Cycle
Technology development and implementation usually follow a software development life cycle (SDLC) methodology. This approach ensures accuracy of information for analysis and decision making, as well as appropriate resources for effective technology management.
You and your team members will use components of the SDLC methodology to develop a
life cycle management report
for the cloud computing architect of a company. This is a group exercise, representing the kind of collaboration often required in the cybersecurity technology community.
There are 11 steps to lead you through this project. Similar steps are typically used in organizational SDLC projects. Most steps should take no more than two hours to complete, and the entire project should take no more than three weeks to complete. Begin with the workplace scenario, and then continue with Step 1: “Initiating the Project.”
Life Cycle Management Report:
A 10- to 15-page double-spaced Word document on data protection techniques for a cloud-based service with citations in APA format. The page count does not include figures or tables. There is no penalty for using additional pages if you need them. Include a minimum of six references. Include a reference list with the report.
As the cloud security architect, you must understand the security development life cycle process. Review the following resources to learn about the security development life cycle process:
security development life cycle
software development methodologies
Click the following links to learn more about critical infrastructure sectors:
Critical Infrastructure Sectors
. Read their descriptions and consider which sector you support in your role.
Process Control Systems: Cybersecurity and Defense
To be completed by a designated team member:
You will begin your Life Cycle Management Report now.
Choose a fictional or actual organization. Describe the mission of the organization and the business need to move to a cloud environment.
Identify the scope of the security architecture and include a topology. To narrow your scope, focus on is.
Melissa ShortridgeWeek 6COLLAPSEMy own attitude has ch.docxwkyra78
Melissa Shortridge
Week 6
COLLAPSE
My own attitude has changed from lack of understanding to enlightenment over the years. In elementary school I never experienced students with disabilities in my classrooms, growing up. But as the years went on and legislation changed students with disabilities started trickling into general education classrooms. They were always ignored by other students and often times had an aide to assist them with assignments. As an adult my heart has opened up to accept all types of people. In the Pennhurst documentary, it was reiterated, they are just people (Baldini, 1968). Which is my outlook on how to treat everyone. Every single person is a human being, treat them the way you wish to be treated. Everyone no matter their race, disability or socio-economic status deserves to be treated humanely.
As an educator I have worked with several different types of students. Students from low socio-economic areas, behavioral issues, vision impairments, hearing impairments, with autism, hyper activity and down syndrome, and with all of these students I have given them my best effort to show them that they are students first. Slavin and Schunk (2017) said it best, “Each student has many characteristics, and the disability is only one of them. To define the child in terms of the disability does him or her an injustice” (p. 235). It is our role as an educator to incorporate different learning styles to give each student, regardless of disabilities, the education that they deserve.
Welcoming students with disabilities into my classroom will be an important aspect in my role as an educator. Allowing each student to feel love and acceptance by peers is important for any students success. Van Brummelen (2009) states, “ It is important to appreciate students with special needs for who they are. Always look beyond their disabilities and teach them as whole persons” (p. 208). Being an advocate for my students with learning disabilities will garner them respect and dignity that they need to be self sufficient. In the Pennhurst documentary, the children did not have complete proper advocacy from the people that worked with them. They were simply shuffled along and not given the proper education and care that they needed to be self-sufficient (Baldini, 1968). “Defend the weak and the fatherless; uphold the cause of the poor and oppressed. Rescue the weak and the needy; deliver them from the hand of the wicked” (Psalm 82:3-4, New International Version). It is our Godly duty to defend individuals who can not defend themselves. In His eyes we are all created equal and in that we all deserve equal treatment and opportunities.
References
Baldini, B. (1968). Suffer the Little Children: Pennhurst Pennsylvania State Home for Disabled Children [Video file]. Retrieved from
https://youtu.be/YG33HvIKOgQ
Slavin, R.E., & Schunk D.H. (2017). Learning Theories: EDUC 500 (1st ed.) Boston, MA: Pearson.
Van Brummelen, H. (2009). Walking wit.
Melissa is a 15-year-old high school student. Over the last week.docxwkyra78
Melissa is a 15-year-old high school student. Over the last week, she had been feeling tired and found it difficult to stay awake in class. By the time the weekend had arrived, she developed a sore throat that made it difficult to eat and even drink. Melissa was too tired to get out of bed, and she said her head ached. On Monday morning, her mother took her to her doctor. Upon completing the physical exam, he told Melissa the lymph nodes were enlarged in her neck and she had a fever. He ordered blood tests and told Melissa he thought she had mononucleosis, a viral infection requiring much bed rest.
Innate and adaptive immune defenses work collectively in destroying invasive microorganisms. What is the interaction between macrophages and T lymphocytes during the presentation of antigen?
Melissa’s illness is caused by a virus. Where are type I interferons produced, and why are they important in combating viral infections?
Humoral immunity involves the activation of B lymphocytes and production of antibodies. What are the general mechanisms of action that make antibodies a key component of an immune response?
.
1. The document describes measuring the angle θ between momentum vectors of particles π- and Σ- produced in a particle interaction using a bubble chamber photograph. The angle can be determined by drawing tangents to the particle tracks and measuring the angle between them.
2. An alternative method to measure the angle not requiring a protractor is described using ratios of distances along the tangents.
3. Instructions are given to estimate uncertainties in measurements taken from repeated readings using calculations of average and standard deviation.
Measurement of the angle θ For better understanding .docxwkyra78
Measurement of the angle θ
For better understanding I am showing you a different particle track diagram bellow. Where at
point C particle 𝜋 − 𝑎𝑛𝑑 Σ− are created and the Σ− decays into 𝜋 ∓ 𝑎𝑛𝑑 K− particles
The angle θ between the π− and Σ− momentum vectors can be determined by drawing tangents
to the π− and Σ− tracks at the point of the Σ− decay. We can then measure the angle between
the tangents using a protractor. Alternative method which does not require a protractor is also
possible. Let AC and BC be the tangents to the π− and Σ− tracks respectively. Drop a
perpendicular (AB) and measure the distances AB and BC. The ratio AB/BC gives the tangent of
the angle180◦−θ. It should be noted that only some of the time will the angle θ exceed 90◦ as
shown here.
Determining the uncertainty of Measurements
In part B, It is asked to estimate the uncertainty of your measurements of 𝜃 and r.
Uncertainty of measurement is the doubt that exists about the result of any measurement. You
might think that well-made rulers, clocks and thermometers should be trustworthy, and give
the right answers. But for every measurement - even the most careful - there is always a margin
of doubt.
It is important not to confuse the terms ‘error’ and ‘uncertainty’.
Error is the difference between the measured value and the ‘true value’ of the thing being
measured.
Uncertainty is a quantification of the doubt about the measurement result
Since there is always a margin of doubt about any measurement, we need to ask ‘How big is the
margin?’ and ‘How bad is the doubt?’ Thus, two numbers are really needed in order to quantify
an uncertainty. One is the width of the margin, or interval. The other is a confidence level, and
states how sure we are that the ‘true value’ is within that margin.
You can increase the amount of information you get from your measurements by taking a
number of readings and carrying out some basic statistical calculations. The two most
important statistical calculations are to find the average or arithmetic mean, and the standard
deviation for a set of numbers.
The ‘true’ value for the standard deviation can only be found from a very large (infinite) set of
readings. From a moderate number of values, only an estimate of the standard deviation can be
found. The symbol s is usually used for the estimated standard deviation.
Suppose you have a set of n readings. Start by finding the average:
For the set of readings x={16, 19, 18, 16, 17, 19, 20, 15, 17 and 13}, the average is �̅� =
∑ 𝑥𝑖
𝑛
=
17.
Next find (𝑥𝑖 − �̅�)
2
Then 𝑠 = √
(𝑥𝑖−�̅�)
2
𝑛−1
= 2.21
Lifetime calculation
In part C you are asked to determine the life time of the neutral particles from their
momentums.
The Σ− lifetime can be approximately determined using the measured values of the Σ− track
lengths. The average momentum of the Σ− particle can be found from its initial and fin
Meaning-Making Forum 2 (Week 5)Meaning-Making Forums 1-4 are thi.docxwkyra78
Meaning-Making Forum 2 (Week 5)
Meaning-Making Forums 1-4 are this course's unique final project.
Be fully engaged in Phase Two!
After reviewing the readings, presentations, lecture notes, articles, and web-engagements, and previous assignments, artificially move your predetermined careseeker (i.e., Crossroads’ Careseekers: Bruce, Joshua, Brody, Justin, or Melissa) through Phase Two.
NOTE: These research-based forums require that you draw upon ALL
of the course readings and learning activities to date, in order to substantively develop each phase in our
Solution
-based, Short-term, Pastoral Counseling (SbStPC) process. Noticeably support each core assertion.
Rapport and Relational Alignment.
Briefly discuss how you will continue to build rapport and shift your relational style in order to best align with the careseeker’s style (i.e., use DISC language) and current behavioral position (i.e., attending, blaming, or willing).
Phase Two Distinctive Features.
Narrate movement of careseeker through Phase Two’s distinctive features (i.e., purpose, goal, chief aim, role/responsibility, use of guiding assumptions) and apply pertinent insights and techniques from ALL the readings, previous assignments, and the Bible.
Supportive Feedback Break.
What portrait, definition(s), key thought(s), and/or assessment insight from the
Quick Reference Guide
might be utilized in the supportive feedback technique?
Phase Two Marker.
Describe a marker that indicates you have collaboratively ‘imagineered” a picture of life without the problem. In what way does this marker indicate the careseeker is in a willing position and ready for Phase Three?
Food for Thought:
When learning a new people skill or counseling technique, is it normal to “feel” awkward and fake? Use at least 1 example and thoughtfully explain how this “feeling” might be normalized.
TIPS:
Carefully Follow Meaning-Making Forum Guidelines & Tips!
Make sure to use headings (5) so that the most inattentive reader may easily follow your thoughts.
Use the annotated outline approach. Bullets should have concise, complete, well-developed sentences or paragraphs.
Foster a “noble-minded” climate for investigating claims through well-supported core assertions (i.e., consider the validation pattern of the Bereans; Acts 17:11).
Noticeably support assertions to facilitate further investigation and to avoid the appearance of plagiarism.
Since you have the required materials (e.g.,
Masterpiece)
, abridge any related citations (Nichols, p. 12) and do not list the required source in a References’ section.
Secondary sources must follow current APA guidelines for citations and References.
Make every effort to prove that you care about the subject matter by proofreading to eliminate grammar and spelling distractions.
A substantive thread (at least 450 words)
.
MBA6231 - 1.1 - project charter.docxProject Charter Pr.docxwkyra78
MBA6231 - 1.1 - project charter.docx
Project Charter
Project Charter
Student Name
Institution
Course Code
Project Title: Michael Joseph Place, The place to be
Project Start Date: 25/7/2018
Projected Finish Date: 25/12/2018
Budget Information: $ 4,500.00
Project Manager: Student name,[email protected], 210- 105 - 6676
Business Need
The project manager will be hosting an evening lounge event that will be targeting the clientele to an upscale lounge to be built in downtown. Through such an event the city will have a positive exposure.
There will be need for effective marketing, music, modern décor and most likely investors. The menu for food and drinks will need to be within budget. The venue needs to have amiable space and adequate seats for all guests.
The first step to this project involves coming up with a plan on a piece of paper. Once this is done the next step will involve selection of vendors to various goods and services. Once everything has been put to perspective the next stage will be to involve investors who will include local business owners. These investors will be encouraged to do so with the exchange for them to market and advertise their products at the event. We will have three packages for investors including Silver, Gold and Platinum packages.
Project Objectives
The proposal is to have a social entertainment evening lounge in Chicago. The project managers will be showcasing the new concept of entertainment by holding a series of events known as “The Place to be!”
· The events will be used to showcase the atmosphere that the new lounge will be offering
· The events will offer the professional audiences an opportunity to network while at the same time being entertained.
· The events will be targeting an audience of 150 attendants
· To have an environment where attendants can dance, dine and drink socially while discussing business.
Approach
This project will be managed in accordance with the PMI approach as modified.
Assumptions/Constraints/Dependencies
The assumption is that with the provision of an exquisite and upscale venue that is mature in Chicago, IL, will be successful due to the fact that there is no such a venue within a 100 mile radius.
One of the likely constraint is finding a venue that grabs attention of the targeted crowd.
The success of these events depends on attracting two sets of individuals. One of them is investors and the other is private professionals who will attend a social event at night.
Initial Risk Factors
· Obtaining a liquor license on time for the event is the major risk factor.
· Failure of attendees despite investing money and time is another risk.
· Failing to complete the organizational plans within 30 days before the event series begin.
· Not attracting any viable investors
Regulatory cost/impact
One of the needed licensing is from the city council where I will be required to get a special event license. This will enable us to have alcohol i.
Medication Errors Led to Disastrous Outcomes1. Search th.docxwkyra78
Medication Errors Led to Disastrous Outcomes
1. Search the internet and learn about the cases of nurses Julie Thao and Kimberly Hiatt.
2. List and discuss lessons that you and all healthcare professionals can learn from these two cases.
3. Describe how the principle of beneficence and the virtue of benevolence could be applied to these cases. Do you think the hospital administrators handled the situations legally and ethically?
4. In addition to benevolence, which other virtues exhibited by their colleagues might have helped Thao and Hiatt?
5. Discuss personal virtues that might be helpful to second victims themselves to navigate the grieving process.
.
Meet, call, Skype or Zoom with a retired athlete and interview himh.docxwkyra78
Meet, call, Skype or Zoom with a retired athlete and interview him/her about his or her transition experiences.
Please use this
interview guide
Actions
when conducting your interview.
Submit a minimum 400 word written reflection with the following:
Brief summary of the athlete's sport career transition
Main takeaways from the conversation
Advice you received and what you learned
Connection to course material
.
Medication Administration Make a list of the most common med.docxwkyra78
Medication Administration
Make a list of the most common medication administration errors and suggest steps that can be taken to prevent these errors.
APA format is required for this written assignment. This is a safe assign homework, no more that 20% of similarities permitted.
.
media portfolio”about chapter 1 to 15 from the book Ci.docxwkyra78
“media portfolio”
about chapter 1 to 15
from the book
Ciccarelli, S., & White, J. (2017).
Psychology
(5th Edition), Pearson.
which can include
newspaper,
magazine clippings
, and other media
that illustrate
psychological concepts covered in this course.
o
It is encouraged to be creative as possible and consider a wide variety of
sources which include: newspapers, magazines, editorials, advice and
medical columns, cartoons, etc. The sky is the l
imit!
o
A minimum of 15 clippings
should be included and should cover each
chapter
in the text book
(Chapters 1 through 15).
o
Each clipping should be explained by providing the source and how it is
related to a particular psychological concept, theory, or research finding
from the text or class lectures.
o
Sources should be in APA format!
Each “media clipping” should be on letter sized (8 ½ x 11) sized paper,
Paper can colored, etc...be creative!
.
Mediation
Name
AMU
Date
Mediation
Recently, I had a dispute with a friend based on sharing of roles and duties at work. If I were to use a mediation to solve the conflict I would have used facilitative mediation instead of evaluative mediation. Facilitative mediation refers to the types of solving conflicts where the mediator creates a process to assist the parties in reaching into a mutual agreement. Evaluative mediation on the other hand refers to the type of mediation where the judge helps the parties in reaching into a resolution through using the weakness of the case (Shrout & Bolger, 2017). The nature of the dispute plays a very huge role when choosing the type of mediation style to use. Since some cases can not fit well or makes it hard to find a solution when using a certain mediation style. For instance work related disputes and family related disputes require mediation that won’t seem to favor one party.
I would use transformative mediation, since it is mostly bases on improving the personal power of each party (Folberg & Taylor, 2016). Also transformative mediation mainly helps in creating a sense of understanding between the two parties through communication so as to solve the dispute. And lastly the reason why I would use the mediation is because; the process that is used does not favor one party. During the process, the mediator listens to both parties and from this he or she is able to help in making the two understand each other and be able to come into a mutual agreement.
References
Folberg, J., & Taylor, A. (2016). Mediation: A comprehensive guide to resolving conflicts without litigation.
Preacher, K. J., & Hayes, A. F. (2014). SPSS and SAS procedures for estimating indirect effects in simple mediation models. Behavior research methods, instruments, & computers, 36(4), 717-731.
Shrout, P. E., & Bolger, N. (2017). Mediation in experimental and nonexperimental studies: new procedures and recommendations. Psychological methods, 7(4), 422.
.
Media coverage influences the publics perception of the crimina.docxwkyra78
Media coverage influences the public's perception of the criminal justice system and the policy agendas of those within the system. This often results in changes within the operational structure of the police, courts, and corrections centers. These changes include the firing of employees, the initiation of internal investigations, and the privatization of services. Respond to the following questions, and support your positions using credible research:
Assignment Guidelines
Address the following in 1,250–1,750 words:
How is the criminal justice system portrayed in the media? Explain.
What impact do the media have on a viewer's perception as to the system's efficacy in dealing with crime? Explain.
Does coverage of sensationalistic and violent crime create fear among the general public? Explain.
Does this fear influence criminal justice policy attitudes? Explain in detail.
Is there a correlation between gender, education, income, age, and perceived neighborhood problems and police effectiveness in dealing with crime? Explain in detail.
In this assignment, external research is essential to successful submission. You must utilize at least 5–7 academic or scholarly external resources to support your arguments.
Be sure to reference all of your sources using APA style.
.
Media Content AnalysisPurpose Evaluate the quality and value of.docxwkyra78
Media Content Analysis
Purpose: Evaluate the quality and value of claims made and information presented by various authors.
Task: Write an essay in which you critically analyze at least 3 published commentaries/presentations related to an issue connected to social media. For each commentary/presentation, your analysis must include an evaluation of the evidence and reasoning presented as well as an examination of the value the commentary/presentation has for its intended audience and others. Compare and contrast various authors’ claims and perspectives.
Points: 200 (160 points from rubric-based assessment; 40 points for submitting a Reviewed Draft*).
Requirements:
Review a minimum of three substantive articles, videos, or presentations that have been published in major print or multimedia sources (e.g., a magazine article; a blog; a YouTube video),
Provide a brief, meaningful summary of each of the published presentations.
Analyze the quality of the claim, evidence, and reasoning in each presentation, with a focus on the validity and value of the presentations.
Use APA format – including in-text parenthetical citations along with a reference list at the end of the assignment.
Answer the following questions in your analysis:
What are the purpose, claims, evidence, and reasoning of each presentation?
What are the qualifications and authority of each author?
In what ways do the authors reflect bias? How do the authors account for their bias?
Are there any significant statements or omissions that might affect the reliability of the information or arguments presented?
Presentation Format:
1000 - 2,000 words
12 point, Times New Roman or Arial Font
Double-Spaced
APA format for body and References page
Follow the paragraph format below to be sure that you have covered all the requirements for the topic you have chosen:
Paragraph #1 1st article title, author and their qualifications along with a summary of it. 20 points
Paragraph #2 2nd article title/presentation, author and their qualifications along with a summary of it 20 points
Paragraph #3 3rd article title/presentation, author and their qualifications and of course a summary of it. 20 points
Paragraph #4 compare and contrast the purpose and the claims of each of the three authors 20 points
Paragraph #5 compare and contrast the evidence shown and the reasoning of each author/presentation 30 points
Paragraph #6 in what ways do the author's reflect bias/fallacies and how do they account for them? 20 points
Paragraph #7 Are there any significant statements or omissions that might affect the reliability of the
information or arguments presented? Which one drew your attention and why? 20 points
APA References alphabetized, double spaced and indented on t.
Mayan gods and goddesses are very much a part of this text. Their i.docxwkyra78
Mayan gods and goddesses are very much a part of this text. Their interactions with one another and later with humans form a major part of our reading. How are the gods and goddesses portrayed in this text? How are those portrayals similar to or different from other representations of gods we have encountered?
.
Media and SocietyIn 1,100 words, complete the followingAn.docxwkyra78
Media and Society
In 1,100 words, complete the following:
Analyze two ways that media affect culture and society. Identify at least one positive and one negative implication arising from technology’s effect on society.
Media has changed exponentially over the past 25 years with the introduction of the Internet and social media. How can people enhance their media literacy? Identify one to two challenges that media will introduce for society in the next 20-30 years and how people can use their media literacy to meet these challenges.
Prepare this assignment according to the guidelines found in the APA Style Guide, located in the Student Success Center. An abstract is not required.
This assignment uses a rubric. Please review the rubric prior to beginning the assignment to become familiar with the expectations for successful completion.
You are required to submit this assignment to LopesWrite. Refer to the
LopesWrite Technical Support articles
for assistance.
FOLLOW THE RUBRIC- CHECK YOUR FINAL PAPER WITH THE ATTACHED RUBRIC!
.
MBA 5110 – Business Organization and ManagementMidterm ExamAns.docxwkyra78
MBA 5110 – Business Organization and Management
Midterm Exam
Answer each of the following questions in this document, inserting your answers between each question. You may use your textbook and notes, but you may not consult with another individual. You may not use the Internet for assistance in answering these questions. Each question should be answered with a minimum of one paragraph, properly formatted according to APA 6th edition guidelines and referencing your textbook. Please list your textbook in a reference section at the end of this document. Submit this Word document with your answers to Moodle.
1. How have organizational structures and management styles changed over the past century?
2. Explain the concept of open and closed systems and how this relates to organization theory.
3. Define each of Porter’s Competitive Strategies and give an example of a company using each of these strategies.
4. Compare vertical and horizontal organizational structures in terms of effectiveness and adaptability in the rapidly changing business environment.
5. Choose one of the following theories and explain the theory. Give an example of a company that demonstrates the chosen theory and how the company uses the theory.
Theories: Chaos Theory, Resource-Dependence Theory, Population-Ecology Perspective, Contingency Theory, or Organizational Learning Theory
Response 1 PD
Question 1
A set of beliefs, norms and values that is shared by a group, culture is a systemic sense that can create a common commitment to an organization’s mission. With identifying markers that extend beyond the individual, it can be represented in a fabric of shared themes and feelings. Whether displayed in forms of dress, symbols, verbal phrases or typical behaviors, its permeance can be silent in its mode of action, yet quite visible to internal and external stakeholders (Daft, 2018).
Serving two fundamental and critical functions, the culture of an organization can be a catalyst in uniting members in how they relate to one another within the organization and how the members follow the same process in relation to the outside environment (Daft, 2018). However, although it is often associated with ethical decision making (Kara, Rojas-Mendez & Turan), the element of inequality can create fear and discourse if an unrealistic and bias culture themes are dictated, thus resulting in disagreement or conflict with management. Therefore, the perception of stakeholders or groups of interest regarding the cultural practices of the organization may not be entirely correct (Gonzalez-Rodriguez, Diaz-Fernández & Biagio, 2019).
Directly related to the perception of the value system of the organization and its management, the acceptable cultural differences that shape the internal behavior of members can have an impact in external relationships (Gonzalez-Rodriguez, Diaz-Fernández & Biagio, 2019). However, as Daft (2018) noted, a mechanistic or controlling system may block any organic input,.
This slide is special for master students (MIBS & MIFB) in UUM. Also useful for readers who are interested in the topic of contemporary Islamic banking.
Thinking of getting a dog? Be aware that breeds like Pit Bulls, Rottweilers, and German Shepherds can be loyal and dangerous. Proper training and socialization are crucial to preventing aggressive behaviors. Ensure safety by understanding their needs and always supervising interactions. Stay safe, and enjoy your furry friends!
Physiology and chemistry of skin and pigmentation, hairs, scalp, lips and nail, Cleansing cream, Lotions, Face powders, Face packs, Lipsticks, Bath products, soaps and baby product,
Preparation and standardization of the following : Tonic, Bleaches, Dentifrices and Mouth washes & Tooth Pastes, Cosmetics for Nails.
How to Manage Your Lost Opportunities in Odoo 17 CRMCeline George
Odoo 17 CRM allows us to track why we lose sales opportunities with "Lost Reasons." This helps analyze our sales process and identify areas for improvement. Here's how to configure lost reasons in Odoo 17 CRM
Executive Directors Chat Leveraging AI for Diversity, Equity, and InclusionTechSoup
Let’s explore the intersection of technology and equity in the final session of our DEI series. Discover how AI tools, like ChatGPT, can be used to support and enhance your nonprofit's DEI initiatives. Participants will gain insights into practical AI applications and get tips for leveraging technology to advance their DEI goals.
How to Build a Module in Odoo 17 Using the Scaffold MethodCeline George
Odoo provides an option for creating a module by using a single line command. By using this command the user can make a whole structure of a module. It is very easy for a beginner to make a module. There is no need to make each file manually. This slide will show how to create a module using the scaffold method.
Exploiting Artificial Intelligence for Empowering Researchers and Faculty, In...Dr. Vinod Kumar Kanvaria
Exploiting Artificial Intelligence for Empowering Researchers and Faculty,
International FDP on Fundamentals of Research in Social Sciences
at Integral University, Lucknow, 06.06.2024
By Dr. Vinod Kumar Kanvaria
Macroeconomics- Movie Location
This will be used as part of your Personal Professional Portfolio once graded.
Objective:
Prepare a presentation or a paper using research, basic comparative analysis, data organization and application of economic information. You will make an informed assessment of an economic climate outside of the United States to accomplish an entertainment industry objective.
বাংলাদেশের অর্থনৈতিক সমীক্ষা ২০২৪ [Bangladesh Economic Review 2024 Bangla.pdf] কম্পিউটার , ট্যাব ও স্মার্ট ফোন ভার্সন সহ সম্পূর্ণ বাংলা ই-বুক বা pdf বই " সুচিপত্র ...বুকমার্ক মেনু 🔖 ও হাইপার লিংক মেনু 📝👆 যুক্ত ..
আমাদের সবার জন্য খুব খুব গুরুত্বপূর্ণ একটি বই ..বিসিএস, ব্যাংক, ইউনিভার্সিটি ভর্তি ও যে কোন প্রতিযোগিতা মূলক পরীক্ষার জন্য এর খুব ইম্পরট্যান্ট একটি বিষয় ...তাছাড়া বাংলাদেশের সাম্প্রতিক যে কোন ডাটা বা তথ্য এই বইতে পাবেন ...
তাই একজন নাগরিক হিসাবে এই তথ্য গুলো আপনার জানা প্রয়োজন ...।
বিসিএস ও ব্যাংক এর লিখিত পরীক্ষা ...+এছাড়া মাধ্যমিক ও উচ্চমাধ্যমিকের স্টুডেন্টদের জন্য অনেক কাজে আসবে ...
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ISO/IEC 27001, ISO/IEC 42001, and GDPR: Best Practices for Implementation and...PECB
Denis is a dynamic and results-driven Chief Information Officer (CIO) with a distinguished career spanning information systems analysis and technical project management. With a proven track record of spearheading the design and delivery of cutting-edge Information Management solutions, he has consistently elevated business operations, streamlined reporting functions, and maximized process efficiency.
Certified as an ISO/IEC 27001: Information Security Management Systems (ISMS) Lead Implementer, Data Protection Officer, and Cyber Risks Analyst, Denis brings a heightened focus on data security, privacy, and cyber resilience to every endeavor.
His expertise extends across a diverse spectrum of reporting, database, and web development applications, underpinned by an exceptional grasp of data storage and virtualization technologies. His proficiency in application testing, database administration, and data cleansing ensures seamless execution of complex projects.
What sets Denis apart is his comprehensive understanding of Business and Systems Analysis technologies, honed through involvement in all phases of the Software Development Lifecycle (SDLC). From meticulous requirements gathering to precise analysis, innovative design, rigorous development, thorough testing, and successful implementation, he has consistently delivered exceptional results.
Throughout his career, he has taken on multifaceted roles, from leading technical project management teams to owning solutions that drive operational excellence. His conscientious and proactive approach is unwavering, whether he is working independently or collaboratively within a team. His ability to connect with colleagues on a personal level underscores his commitment to fostering a harmonious and productive workplace environment.
Date: May 29, 2024
Tags: Information Security, ISO/IEC 27001, ISO/IEC 42001, Artificial Intelligence, GDPR
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Training: ISO/IEC 27001 Information Security Management System - EN | PECB
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A Strategic Approach: GenAI in EducationPeter Windle
Artificial Intelligence (AI) technologies such as Generative AI, Image Generators and Large Language Models have had a dramatic impact on teaching, learning and assessment over the past 18 months. The most immediate threat AI posed was to Academic Integrity with Higher Education Institutes (HEIs) focusing their efforts on combating the use of GenAI in assessment. Guidelines were developed for staff and students, policies put in place too. Innovative educators have forged paths in the use of Generative AI for teaching, learning and assessments leading to pockets of transformation springing up across HEIs, often with little or no top-down guidance, support or direction.
This Gasta posits a strategic approach to integrating AI into HEIs to prepare staff, students and the curriculum for an evolving world and workplace. We will highlight the advantages of working with these technologies beyond the realm of teaching, learning and assessment by considering prompt engineering skills, industry impact, curriculum changes, and the need for staff upskilling. In contrast, not engaging strategically with Generative AI poses risks, including falling behind peers, missed opportunities and failing to ensure our graduates remain employable. The rapid evolution of AI technologies necessitates a proactive and strategic approach if we are to remain relevant.
1. project4-ast/.DS_Store
project4-ast/ast.c
#include "symbolTable.h"
#include "ast.h"
extern SymbolTableStackEntryPtr symbolStackTop;
extern int scopeDepth;
//creates a new expression node
AstNodePtr new_ExprNode(ExpKind kind)
{
}
//creates a new statement node
AstNodePtr new_StmtNode(StmtKind kind)
{
}
//creates a new type node for entry into symbol table
Type* new_type(TypeKind kind)
{
}
2. project4-ast/ast.h
#include "globals.h"
#include "symbolTable.h"
typedef enum {STMT, EXPRESSION, FORMALVAR,
METHOD} NodeKind;
typedef enum {IF_THEN_ELSE_STMT, WHILE_STMT,
RETURN_STMT, COMPOUND_STMT,
EXPRESSION_STMT } StmtKind;
typedef enum {VAR_EXP, ARRAY_EXP, ASSI_EXP,
ADD_EXP, SUB_EXP, MULT_EXP, DIV_EXP,
GT_EXP, LT_EXP, GE_EXP, LE_EXP, EQ_EXP,
NE_EXP, CALL_EXP, CONST_EXP
}ExpKind;
typedef struct node {
NodeKind nKind;
StmtKind sKind;
ExpKind eKind;
struct node *children[MAXCHILDREN]; // max needed for
if_then_else
struct node *sibling; //List of statements, formal argument
Type *nType; //node's type for typechecking expressions for
HW5
ElementPtr nSymbolPtr; // for variable and array expressions
int nValue; // for integer constants
SymbolTablePtr nSymbolTabPtr; //For a block, its symbol
table
char *fname; // for a call expr, the name of the called
function
int nLinenumber;
}AstNode;
23. project4-ast/symbolTable.c
#include "symbolTable.h"
// Top should point to the top of the scope stack,
// which is the most recent scope pushed
SymbolTableStackEntryPtr symbolStackTop;
int scopeDepth;
/* global function prototypes */
//allocate the global scope entry and symbol table --and set
scopeDepth to 0
// The global scope remains till the end of the program
int initSymbolTable()
{
//initialize a stack
int i=0;
symbolStackTop = (SymbolTableStackEntryPtr) malloc
(sizeof(struct symbolTableStackEntry));
if (symbolStackTop == NULL) return 0;
symbolStackTop -> symbolTablePtr = (SymbolTable*)
malloc (sizeof(SymbolTable));
for(i=0; i<MAXHASHSIZE; i++)
symbolStackTop -> symbolTablePtr->hashTable[i] =
NULL;
symbolStackTop->prevScope = NULL;
scopeDepth = 0;
//printf("n Initialized Stack with Global Hash Table");
return 1;
}
24. // Look up a given entry
ElementPtr symLookup(char *name)
{
char *a = name;
SymbolTableStackEntryPtr iter = symbolStackTop;
int ascii = 0,depth = scopeDepth ;
while(*a!='0')
{
ascii+= (int) *a;
a++;
}
while(iter)
{
ElementPtr symelement = iter->symbolTablePtr-
>hashTable[ascii%16];
while(symelement)
{
if(strcmp(symelement->id, name) == 0)
{
//printf("n Found symbol %s at scope
depth %d",name, depth);
return symelement;
}
else
symelement = symelement->next;
}
iter = iter->prevScope;
//printf("n Did not find symbol %s at scope depth
%d",name, depth);
depth--;
}
return NULL;
}
25. // Insert an element with a specified type in a particular line
number
// initialize the scope depth of the entry from the global var
scopeDepth
//symInsert("counter", typ, 10);
ElementPtr symInsert(char *name, Type *type, int line)
{
ElementPtr new_element = (ElementPtr) malloc
(sizeof(Element));
char *a = name;
int ascii = 0 ;
while(*a!='0')
{
ascii+= (int) *a;
a++;
}
new_element->key = ascii%16;
new_element->id = strdup(name);
new_element->linenumber = line;
new_element->scope = scopeDepth;
new_element->stype = type;
new_element->snode = NULL;
if(!symbolStackTop->symbolTablePtr-
>hashTable[new_element->key]) // if the first element of hash
table for this ascii is null
{
new_element->next = NULL;
symbolStackTop->symbolTablePtr-
>hashTable[new_element->key] = new_element;
}
else
{
new_element->next = symbolStackTop-
26. >symbolTablePtr->hashTable[new_element->key];
symbolStackTop->symbolTablePtr-
>hashTable[new_element->key] = new_element;
}
//printf("n Inserted %s at scope depth %d with ascii %d
",new_element->id,scopeDepth,new_element->key);
return symbolStackTop->symbolTablePtr-
>hashTable[new_element->key];
}
//push a new entry to the symbol stack
// This should modify the variable top and change the scope
depth
int enterScope()
{
int i;
SymbolTableStackEntryPtr newSymbolStackEntry =
(SymbolTableStackEntryPtr) malloc (sizeof(struct
symbolTableStackEntry));
if (newSymbolStackEntry == NULL) return 0;
newSymbolStackEntry -> symbolTablePtr =
(SymbolTable*) malloc (sizeof(SymbolTable));
for(i=0; i<MAXHASHSIZE; i++)
newSymbolStackEntry -> symbolTablePtr-
>hashTable[i] = NULL;
newSymbolStackEntry->prevScope = symbolStackTop;
symbolStackTop = newSymbolStackEntry;
scopeDepth++;
//printf("n New Scope");
return 1;
}
27. //pop an entry off the symbol stack
// This should modify top and change scope depth
void leaveScope()
{
if (!symbolStackTop)
printf("n Error .. cannot leave global scope");
else if(!symbolStackTop->prevScope)
symbolStackTop = NULL;
else
symbolStackTop = symbolStackTop->prevScope;
scopeDepth--;
}
// Do not modify this function
void printElement(ElementPtr symelement) {
if (symelement != NULL) {
printf("nLine %d: %s", symelement-
>linenumber,symelement->id);
}
else printf("Wrong call! symbol table entry NULL");
}
//should traverse through the entire symbol table and print it
// must use the printElement function given above
void printSymbolTable()
{
int i;
SymbolTableStackEntryPtr SymbolStackEntry =
symbolStackTop;
while(SymbolStackEntry)
{
for(i=0; i<MAXHASHSIZE;i++)
{
ElementPtr symelement = SymbolStackEntry-
29. /* data structure of one element in the symbol table */
typedef enum {VOID, INT, ARRAY, FUNCTION} TypeKind;
typedef struct type{
TypeKind kind; /* one from the enum above */
int dimension; /* for arrays */
struct type *function; /*function argument and return types
*/
/* Ignore this field until HW5 */
}Type;
typedef Type *TypePtr;
typedef struct element {
int key;
char * id;
int linenumber;
int scope; /* scope depth at declaration */
Type *stype; /* pointer to the type infomation
*/
struct element *next; /* pointer to the next
symbol with the
same hash table index */
struct node *snode; /* (New) AST Node for method
declartion */
} Element;
typedef Element *ElementPtr;
typedef ElementPtr HashTableEntry;
/* data structure of the symbol table */
typedef struct symbolTable {
30. HashTableEntry hashTable[MAXHASHSIZE]; /*
hash table */
} SymbolTable;
typedef SymbolTable *SymbolTablePtr;
typedef struct symbolTableStackEntry {
SymbolTablePtr symbolTablePtr;
struct symbolTableStackEntry *prevScope;
} SymbolTableStackEntry;
typedef SymbolTableStackEntry
*SymbolTableStackEntryPtr;
int initSymbolTable() ;
ElementPtr symLookup(char *);
ElementPtr symInsert(char *, Type *, int );
int enterScope();
void leaveScope();
#endif
project4-ast/util.c
/* Original Code: Silvano Bonacia, Fall 2006 */
/* Modifications and changes, Prof. Venkat, Spring 08 */
#include "ast.h"
#include "util.h"
extern AstNode *program;
extern SymbolTableStackEntryPtr symbolStackTop;
extern void printSymbolTable();
31. #define PAD_STR " "
int indLevel = 0;
void pad (int level) {
int i;
for(i=0;i<level;i++)
printf("%s", PAD_STR);
}
/*
* Print the parameters of the method (parameters being in the
* current scope)
*/
void printMethodParams (SymbolTableStackEntryPtr scope) {
int i;
SymbolTableStackEntryPtr SymbolStackEntry = scope;
for(i=0; i<MAXHASHSIZE;i++) {
ElementPtr symelement = SymbolStackEntry-
>symbolTablePtr->hashTable[i];
while(symelement) {
switch(symelement->stype->kind) {
case INT :
printf("int %s", symelement->id);
break;
case ARRAY :
printf("int %s[]", symelement->id);
break;
case VOID :
printf("void");
break;
case FUNCTION :
break;
}
symelement = symelement->next;
32. if(symelement)
printf(", ");
}
}
}
/*
* Print the variable declarations of the scope.
* Return the number of variables
*/
int printVarDeclarations (SymbolTablePtr scope)
{
int noVar = 0;
int i;
for(i=0; i<MAXHASHSIZE;i++) {
ElementPtr symelement = scope->hashTable[i];
while(symelement) {
pad(indLevel);
switch(symelement->stype->kind) {
case INT :
printf("int %s;n", symelement->id);
noVar++;
break;
case ARRAY :
printf("int %s[%d];n", symelement->id,
symelement->stype->dimension);
noVar++;
break;
case VOID:
break;
case FUNCTION :
break;
}
symelement = symelement->next;
}
33. }
return noVar;
}
//traverses through the entire program and symbol table and
prints it
//the output must match the program with the exception of white
spaces
//do a diff -w to ignre white spaces
void printType(TypePtr type, int dummy){
switch(type->kind) {
case INT :
printf("int");
break;
case ARRAY :
printf("int");
break;
case VOID:
printf("void");
break;
case FUNCTION :
printType(type->function, 0);
break;
}
}
void print_Expression(AstNodePtr expr, int endWithSemi) {
if(expr == NULL) {
return;
}
switch(expr->eKind) {
case VAR_EXP :
printf("%s", expr->nSymbolPtr->id);
break;
case ARRAY_EXP :
38. printf(";n");
}
indLevel--;
pad(indLevel);
printf("}n");
break;
case EXPRESSION_STMT :
print_Expression(stmt->children[0], 1);
break;
}
//printf("sibling : %dn", stmt->sibling);
print_Statement(stmt->sibling); // Print the next statement
}
void print_Ast_Recursion(AstNodePtr root) {
//printf("print_Ast_Recursion: root = %dn", root);
/*
* End the recursion
*/
if(root == NULL)
return;
switch(root->nKind) {
case METHOD :
//printf("root->nKind = METHODn");
printType(root->nType, 0);
printf(" %s(", root->nSymbolPtr->id);
if(root->children[0] == NULL)
printf("void");
else
print_Ast_Recursion(root->children[0]); // print the
parameters of the method
printf(")n");
print_Ast_Recursion(root->children[1]); // print the body of
the method
printf("n");
39. print_Ast_Recursion(root->sibling); // print the next method
break;
case FORMALVAR :
//printf("root->nKind = FORMALVARn");
printType(root->nSymbolPtr->stype, 0); // print the type
printf(" %s", root->nSymbolPtr->id); // print the name of
the variable
if(root->nSymbolPtr->stype->kind == ARRAY)
printf("[]");
/*
* Print the next parameter if there's one
*/
if(root->sibling != NULL) {
printf(", ");
print_Ast_Recursion(root->sibling);
}
break;
case STMT :
//printf("root->nKind = STMTn");
print_Statement(root);
break;
case EXPRESSION :
//printf("root->nKind = EXPRESSIONn");
print_Expression(root, 1); // I don't think it ever gets here
break;
}
}
void print_Ast() {
/*
* First print the entire symbol table
*/
//printSymbolTable();
/*
* Then print the program
40. */
indLevel = 0;
if(printVarDeclarations(symbolStackTop->symbolTablePtr) >
0)
printf("n");
print_Ast_Recursion(program);
}
project4-ast/util.h
extern void printNode(AstNodePtr, int);
extern void printType(TypePtr, int);
lex_yacc.pdf
A GUIDE TO LEX & YACC
BY THOMAS NIEMANN
2
PREFACE
This document explains how to construct a compiler using lex
and yacc. Lex and yacc are
tools used to generate lexical analyzers and parsers. I assume
41. you can program in C, and
understand data structures such as linked-lists and trees.
The introduction describes the basic building blocks of a
compiler and explains the
interaction between lex and yacc. The next two sections
describe lex and yacc in more
detail. With this background, we construct a sophisticated
calculator. Conventional
arithmetic operations and control statements, such as if-else and
while, are implemented.
With minor changes, we convert the calculator into a compiler
for a stack-based machine.
The remaining sections discuss issues that commonly arise in
compiler writing. Source
code for examples may be downloaded from the web site listed
below.
Permission to reproduce portions of this document is given
provided the web site
listed below is referenced, and no additional restrictions apply.
Source code, when part of
a software project, may be used freely without reference to the
author.
THOMAS NIEMANN
Portland, Oregon
[email protected]
http://members.xoom.com/thomasn
mailto:[email protected]
http://members.xoom.com/thomasn
3
42. CONTENTS
1. INTRODUCTION
4
2. LEX
6
2.1 Theory 6
2.2 Practice 7
3. YACC
12
3.1 Theory 12
3.2 Practice, Part I 14
3.3 Practice, Part II 17
4. CALCULATOR
20
4.1 Description 20
4.2 Include File 23
4.3 Lex Input 24
4.4 Yacc Input 25
4.5 Interpreter 29
4.6 Compiler 30
5. MORE LEX
32
5.1 Strings 32
5.2 Reserved Words 33
5.3 Debugging Lex 33
6. MORE YACC
35
6.1 Recursion 35
6.2 If-Else Ambiguity 35
43. 6.3 Error Messages 36
6.4 Inherited Attributes 37
6.5 Embedded Actions 37
6.6 Debugging Yacc 38
7. BIBLIOGRAPHY
39
4
1. Introduction
Until 1975, writing a compiler was a very time-consuming
process. Then Lesk [1975]
and Johnson [1975] published papers on lex and yacc. These
utilities greatly simplify
compiler writing. Implementation details for lex and yacc may
be found in Aho [1986].
Lex and yacc are available from
• Mortice Kern Systems (MKS), at http://www.mks.com,
• GNU flex and bison, at http://www.gnu.org,
• Ming, at http://agnes.dida.physik.uni-
essen.de/~janjaap/mingw32,
• Cygnus, at http://www.cygnus.com/misc/gnu-win32, and
• me, at
http://members.xoom.com/thomasn/y_gnu.zip (executables), and
http://members.xoom.com/thomasn/y_gnus.zip (source for
y_gnu.zip).
The version from MKS is a high-quality commercial product
that retails for about
$300US. GNU software is free. Output from flex may be used in
a commercial product,
44. and, as of version 1.24, the same is true for bison. Ming and
Cygnus are 32-bit Windows-
95/NT ports of the GNU software. My version is based on
Ming’s, but is compiled with
Visual C++ and includes a minor bug fix in the file handling
routine. If you download my
version, be sure to retain directory structure when you unzip.
Lexical Analyzer
Syntax Analyzer
a = b + c * d
id1 = id2 + id3 * id4
=
+
*
id1
source code
tokens
syntax tree
id2
id3 id4
load id3
mul id4
45. add id2
store id1
Code Generator
generated code
Figure 1-1: Compilation Sequence
http://members.xoom.com/thomasn/y_lex.pdf
http://members.xoom.com/thomasn/y_yacc.pdf
http://www.amazon.com/exec/obidos/ISBN=0201100886/none01
A/#Bibliography
http://www.mks.com/
http://www.gnu.org/
http://agnes.dida.physik.uni-essen.de/~janjaap/mingw32
http://www.cygnus.com/misc/gnu-win32
http://members.xoom.com/thomasn/y_gnu.zip
http://members.xoom.com/thomasn/y_gnus.zip
5
Lex generates C code for a lexical analyzer, or scanner. It uses
patterns that match
strings in the input and converts the strings to tokens. Tokens
are numerical
representations of strings, and simplify processing. This is
illustrated in Figure 1-1.
As lex finds identifiers in the input stream, it enters them in a
symbol table. The
symbol table may also contain other information such as data
type (integer or real) and
location of the variable in memory. All subsequent references to
identifiers refer to the
46. appropriate symbol table index.
Yacc generates C code for a syntax analyzer, or parser. Yacc
uses grammar rules that
allow it to analyze tokens from lex and create a syntax tree. A
syntax tree imposes a
hierarchical structure on tokens. For example, operator
precedence and associativity are
apparent in the syntax tree. The next step, code generation, does
a depth-first walk of the
syntax tree to generate code. Some compilers produce machine
code, while others, as
shown above, output assembly.
lex
yacc
cc
bas.y
bas.l lex.yy.c
y.tab.c
bas.exe
source
compiled output
(yylex)
(yyparse)
y.tab.h
47. Figure 1-2: Building a Compiler with Lex/Yacc
Figure 1-2 illustrates the file naming conventions used by lex
and yacc. We'll assume
our goal is to write a BASIC compiler. First, we need to specify
all pattern matching rules
for lex (bas.l) and grammar rules for yacc (bas.y). Commands to
create our compiler,
bas.exe, are listed below:
yacc –d bas.y # create y.tab.h, y.tab.c
lex bas.l # create lex.yy.c
cc lex.yy.c y.tab.c –obas.exe # compile/link
Yacc reads the grammar descriptions in bas.y and generates a
parser, function
yyparse, in file y.tab.c. Included in file bas.y are token
declarations. These are
converted to constant definitions by yacc and placed in file
y.tab.h. Lex reads the
pattern descriptions in bas.l, includes file y.tab.h, and generates
a lexical analyzer,
function yylex, in file lex.yy.c.
Finally, the lexer and parser are compiled and linked together to
form the executable,
bas.exe. From main, we call yyparse to run the compiler.
Function yyparse
automatically calls yylex to obtain each token.
6
2. Lex
48. 2.1 Theory
The first phase in a compiler reads the input source and
converts strings in the source to
tokens. Using regular expressions, we can specify patterns to
lex that allow it to scan and
match strings in the input. Each pattern in lex has an associated
action. Typically an
action returns a token, representing the matched string, for
subsequent use by the parser.
To begin with, however, we will simply print the matched string
rather than return a
token value. We may scan for identifiers using the regular
expression
letter(letter|digit)*
This pattern matches a string of characters that begins with a
single letter, and is followed
by zero or more letters or digits. This example nicely illustrates
operations allowed in
regular expressions:
• repetition, expressed by the “*” operator
• alternation, expressed by the “|” operator
• concatenation
Any regular expression expressions may be expressed as a finite
state automaton
(FSA). We can represent an FSA using states, and transitions
between states. There is one
start state, and one or more final or accepting states.
0 1 2
letter
49. letter or digit
otherstart
Figure 2-1: Finite State Automaton
In Figure 2-1, state 0 is the start state, and state 2 is the
accepting state. As characters are
read, we make a transition from one state to another. When the
first letter is read, we
transition to state 1. We remain in state 1 as more letters or
digits are read. When we read
a character other than a letter or digit, we transition to state 2,
the accepting state. Any
FSA may be expressed as a computer program. For example, our
3-state machine is
easily programmed:
7
start: goto state0
state0: read c
if c = letter goto state1
goto state0
state1: read c
if c = letter goto state1
if c = digit goto state1
goto state2
state2: accept string
This is the technique used by lex. Regular expressions are
50. translated by lex to a computer
program that mimics an FSA. Using the next input character,
and current state, the next
state is easily determined by indexing into a computer-
generated state table.
Now we can easily understand some of lex’s limitations. For
example, lex cannot be
used to recognize nested structures such as parentheses. Nested
structures are handled by
incorporating a stack. Whenever we encounter a “(”, we push it
on the stack. When a “)”
is encountered, we match it with the top of the stack, and pop
the stack. Lex, however,
only has states and transitions between states. Since it has no
stack, it is not well suited
for parsing nested structures. Yacc augments an FSA with a
stack, and can process
constructs such as parentheses with ease. The important thing is
to use the right tool for
the job. Lex is good at pattern matching. Yacc is appropriate for
more challenging tasks.
2.2 Practice
Metacharacter Matches
. any character except newline
n newline
* zero or more copies of preceding expression
+ one or more copies of preceding expression
? zero or one copy of preceeding expression
^ beginning of line
$ end of line
a|b a or b
(ab)+ one or more copies of ab (grouping)
"a+b" literal “a+b” (C escapes still work)
51. [] character class
Table 2-1: Pattern Matching Primitives
8
Expression Matches
abc abc
abc* ab, abc, abcc, abccc, …
abc+ abc, abcc, abccc, …
a(bc)+ abc, abcbc, abcbcbc, …
a(bc)? a, abc
[abc] a, b, c
[a-z] any letter, a through z
[a-z] a, -, z
[-az] -, a, z
[A-Za-z0-9]+ one or more alphanumeric characters
[ tn]+ whitespace
[^ab] anything except: a, b
[a^b] a, ^, b
[a|b] a, |, b
a|b a or b
Table 2-2: Pattern Matching Examples
52. Regular expressions in lex are composed of metacharacters
(Table 2-1). Pattern matching
examples are shown in Table 2-2. Within a character class,
normal operators lose their
meaning. Two operators allowed in a character class are the
hyphen (“-”) and circumflex
(“^”). When used between two characters, the hyphen represents
a range of characters.
The circumflex, when used as the first character, negates the
expression. If two patterns
match the same string, the longest match wins. In case both
matches are the same length,
then the first pattern listed is used.
Input to Lex is divided into three sections, with %% dividing
the sections. This is best
illustrated by example. The first example is the shortest
possible lex file:
%%
Input is copied to output, one character at a time. The first %%
is always required, as there
must always be a rules section. However, if we don’t specify
any rules, then the default
action is to match everything and copy it to output. Defaults for
input and output are
stdin and stdout, respectively. Here is the same example, with
defaults explicitly
coded:
... definitions ...
%%
... rules ...
%%
53. ... subroutines ...
9
%%
/* match everything except newline */
. ECHO;
/* match newline */
n ECHO;
%%
int yywrap(void) {
return 1;
}
int main(void) {
yylex();
return 0;
}
Two patterns have been specified in the rules section. Each
pattern must begin in column
one. This is followed by whitespace (space, tab or newline), and
an optional action
associated with the pattern. The action may be a single C
statement, or multiple C
statements enclosed in braces. Anything not starting in column
one is copied verbatim to
the generated C file. We may take advantage of this behavior to
54. specify comments in our
lex file. In this example there are two patterns, “.” and “n”,
with an ECHO action
associated for each pattern. Several macros and variables are
predefined by lex. ECHO is a
macro that writes code matched by the pattern. This is the
default action for any
unmatched strings. Typically, ECHO is defined as:
#define ECHO fwrite(yytext, yyleng, 1, yyout)
Variable yytext is a pointer to the matched string (NULL-
terminated), and yyleng is
the length of the matched string. Variable yyout is the output
file, and defaults to
stdout. Function yywrap is called by lex when input is
exhausted. Return 1 if you are
done, or 0 if more processing is required. Every C program
requires a main function. In
this case, we simply call yylex, the main entry-point for lex.
Some implementations of
lex include copies of main and yywrap in a library, eliminating
the need to code them
explicitly. This is why our first example, the shortest lex
program, functioned properly.
10
name function
int yylex(void) call to invoke lexer, returns token
char *yytext pointer to matched string
yyleng length of matched string
yylval value associated with token
int yywrap(void) wrapup, return 1 if done, 0 if not done
55. FILE *yyout output file
FILE *yyin input file
INITIAL initial start condition
BEGIN condition switch start condition
ECHO write matched string
Table 2-3: Lex Predefined Variables
Here’s a program that does nothing at all. All input is matched,
but no action is
associated with any pattern, so there will be no output.
%%
.
n
The following example prepends line numbers to each line in a
file. Some
implementations of lex predefine and calculate yylineno. The
input file for lex is yyin,
and defaults to stdin.
%{
int yylineno;
%}
%%
^(.*)n printf("%4dt%s", ++yylineno, yytext);
%%
int main(int argc, char *argv[]) {
yyin = fopen(argv[1], "r");
yylex();
fclose(yyin);
}
56. The definitions section is composed of substitutions, code, and
start states. Code in
the definitions section is simply copied as-is to the top of the
generated C file, and must
be bracketed with “%{“ and “%}” markers. Substitutions
simplify pattern-matching rules.
For example, we may define digits and letters:
11
digit [0-9]
letter [A-Za-z]
%{
int count;
%}
%%
/* match identifier */
{letter}({letter}|{digit})* count++;
%%
int main(void) {
yylex();
printf("number of identifiers = %dn", count);
return 0;
}
Whitespace must separate the defining term and the associated
expression.
References to substitutions in the rules section are surrounded
by braces ({letter}) to
57. distinguish them from literals. When we have a match in the
rules section, the associated
C code is executed. Here is a scanner that counts the number of
characters, words, and
lines in a file (similar to Unix wc):
%{
int nchar, nword, nline;
%}
%%
n { nline++; nchar++; }
[^ tn]+ { nword++, nchar += yyleng; }
. { nchar++; }
%%
int main(void) {
yylex();
printf("%dt%dt%dn", nchar, nword, nline);
return 0;
}
12
3. Yacc
3.1 Theory
Grammars for yacc are described using a variant of Backus Naur
Form (BNF). This
technique was pioneered by John Backus and Peter Naur, and
used to describe
ALGOL60. A BNF grammar can be used to express context-free
languages. Most
58. constructs in modern programming languages can be represented
in BNF. For example,
the grammar for an expression that multiplies and adds numbers
is
1 E -> E + E
2 E -> E * E
3 E -> id
Three productions have been specified. Terms that appear on the
left-hand side (lhs) of a
production, such as E (expression) are nonterminals. Terms such
as id (identifier) are
terminals (tokens returned by lex) and only appear on the right-
hand side (rhs) of a
production. This grammar specifies that an expression may be
the sum of two
expressions, the product of two expressions, or an identifier.
We can use this grammar to
generate expressions:
E -> E * E (r2)
-> E * z (r3)
-> E + E * z (r1)
-> E + y * z (r3)
-> x + y * z (r3)
At each step we expanded a term, replacing the lhs of a
production with the
corresponding rhs. The numbers on the right indicate which rule
applied. To parse an
expression, we actually need to do the reverse operation.
Instead of starting with a single
nonterminal (start symbol) and generating an expression from a
grammar, we need to
reduce an expression to a single nonterminal. This is known as
59. bottom-up or shift-reduce
parsing, and uses a stack for storing terms. Here is the same
derivation, but in reverse
order:
13
1 . x + y * z shift
2 x . + y * z reduce(r3)
3 E . + y * z shift
4 E + . y * z shift
5 E + y . * z reduce(r3)
6 E + E . * z shift
7 E + E * . z shift
8 E + E * z . reduce(r3)
9 E + E * E . reduce(r2) emit multiply
10 E + E . reduce(r1) emit add
11 E . accept
Terms to the left of the dot are on the stack, while remaining
input is to the right of the
dot. We start by shifting tokens onto the stack. When the top of
the stack matches the rhs
of a production, we replace the matched tokens on the stack
with the lhs of the
production. Conceptually, the matched tokens of the rhs are
popped off the stack, and the
lhs of the production is pushed on the stack. The matched
tokens are known as a handle,
and we are reducing the handle to the lhs of the production.
This process continues until
we have shifted all input to the stack, and only the starting
nonterminal remains on the
stack. In step 1 we shift the x to the stack. Step 2 applies rule r3
60. to the stack, changing x
to E. We continue shifting and reducing, until a single
nonterminal, the start symbol,
remains in the stack. In step 9, when we reduce rule r2, we emit
the multiply instruction.
Similarly, the add instruction is emitted in step 10. Thus,
multiply has a higher
precedence than addition.
Consider, however, the shift at step 6. Instead of shifting, we
could have reduced,
applying rule r1. This would result in addition having a higher
precedence than
multiplication. This is known as a shift-reduce conflict. Our
grammar is ambiguous, as
there is more than one possible derivation that will yield the
expression. In this case,
operator precedence is affected. As another example,
associativity in the rule
E -> E + E
is ambiguous, for we may recurse on the left or the right. To
remedy the situation, we
could rewrite the grammar, or supply yacc with directives that
indicate which operator
has precedence. The latter method is simpler, and will be
demonstrated in the practice
section.
The following grammar has a reduce-reduce conflict. With an id
on the stack, we
may reduce to T, or reduce to E.
E -> T
E -> id
61. T -> id
Yacc takes a default action when there is a conflict. For shift-
reduce conflicts, yacc will
shift. For reduce-reduce conflicts, it will use the first rule in the
listing. It also issues a
warning message whenever a conflict exists. The warnings may
be suppressed by making
14
the grammar unambiguous. Several methods for removing
ambiguity will be presented in
subsequent sections.
3.2 Practice, Part I
Input to yacc is divided into three sections. The definitions
section consists of token
declarations, and C code bracketed by “%{“ and “%}”. The BNF
grammar is placed in the
rules section, and user subroutines are added in the subroutines
section.
This is best illustrated by constructing a small calculator that
can add and subtract
numbers. We’ll begin by examining the linkage between lex and
yacc. Here is the
definitions section for the yacc input file:
%token INTEGER
This definition declares an INTEGER token. When we run yacc,
it generates a parser in
62. file y.tab.c, and also creates an include file, y.tab.h:
#ifndef YYSTYPE
#define YYSTYPE int
#endif
#define INTEGER 258
extern YYSTYPE yylval;
Lex includes this file and utilizes the definitions for token
values. To obtain tokens, yacc
calls yylex. Function yylex has a return type of int, and returns
the token value.
Values associated with the token are returned by lex in variable
yylval. For example,
[0-9]+ {
yylval = atoi(yytext);
return INTEGER;
}
would store the value of the integer in yylval, and return token
INTEGER to yacc. The
type of yylval is determined by YYSTYPE. Since the default
type is integer, this works
well in this case. Token values 0-255 are reserved for character
values. For example, if
you had a rule such as
[-+] return *yytext; /* return operator */
... definitions ...
%%
... rules ...
%%
... subroutines ...
63. 15
the character value for minus or plus is returned. Note that we
placed the minus sign first
so that it wouldn’t be mistaken for a range designator.
Generated token values typically
start around 258, as lex reserves several values for end-of-file
and error processing. Here
is the complete lex input specification for our calculator:
%{
#include "y.tab.h"
%}
%%
[0-9]+ {
yylval = atoi(yytext);
return INTEGER;
}
[-+n] return *yytext;
[ t] ; /* skip whitespace */
. yyerror("invalid character");
%%
int yywrap(void) {
return 1;
64. }
Internally, yacc maintains two stacks in memory; a parse stack
and a value stack. The
parse stack contains terminals and nonterminals, and represents
the current parsing state.
The value stack is an array of YYSTYPE elements, and
associates a value with each
element in the parse stack. For example, when lex returns an
INTEGER token, yacc shifts
this token to the parse stack. At the same time, the
corresponding yylval is shifted to
the value stack. The parse and value stacks are always
synchronized, so finding a value
related to a token on the stack is easily accomplished. Here is
the yacc input specification
for our calculator:
16
%token INTEGER
%%
program:
program expr 'n' { printf("%dn", $2); }
|
;
expr:
INTEGER { $$ = $1; }
| expr '+' expr { $$ = $1 + $3; }
| expr '-' expr { $$ = $1 - $3; }
;
65. %%
int yyerror(char *s) {
fprintf(stderr, "%sn", s);
return 0;
}
int main(void) {
yyparse();
return 0;
}
The rules section resembles the BNF grammar discussed earlier.
The left-hand side of a
production, or nonterminal, is entered left-justified, followed by
a colon. This is followed
by the right-hand side of the production. Actions associated
with a rule are entered in
braces.
By utilizing left-recursion, we have specified that a program
consists of zero or more
expressions. Each expression terminates with a newline. When a
newline is detected, we
print the value of the expression. When we apply the rule
expr: expr '+' expr { $$ = $1 + $3; }
we replace the right-hand side of the production in the parse
stack with the left-hand side
of the same production. In this case, we pop “expr '+' expr” and
push “expr”. We
have reduced the stack by popping three terms off the stack, and
66. pushing back one term.
We may reference positions in the value stack in our C code by
specifying “$1” for the
first term on the right-hand side of the production, “$2” for the
second, and so on. “$$”
designates the top of the stack after reduction has taken place.
The above action adds the
value associated with two expressions, pops three terms off the
value stack, and pushes
back a single sum. Thus, the parse and value stacks remain
synchronized.
17
Numeric values are initially entered on the stack when we
reduce from INTEGER to
expr. After INTEGER is shifted to the stack, we apply the rule
expr: INTEGER { $$ = $1; }
The INTEGER token is popped off the parse stack, followed by
a push of expr. For the
value stack, we pop the integer value off the stack, and then
push it back on again. In
other words, we do nothing. In fact, this is the default action,
and need not be specified.
Finally, when a newline is encountered, the value associated
with expr is printed.
In the event of syntax errors, yacc calls the user-supplied
function yyerror. If you
need to modify the interface to yyerror, you can alter the canned
file that yacc includes
to fit your needs. The last function in our yacc specification is
67. main … in case you were
wondering where it was. This example still has an ambiguous
grammar. Yacc will issue
shift-reduce warnings, but will still process the grammar using
shift as the default
operation.
3.3 Practice, Part II
In this section we will extend the calculator from the previous
section to incorporate
some new functionality. New features include arithmetic
operators multiply, and divide.
Parentheses may be used to over-ride operator precedence, and
single-character variables
may be specified in assignment statements. The following
illustrates sample input and
calculator output:
user: 3 * (4 + 5)
calc: 27
user: x = 3 * (5 + 4)
user: y = 5
user: x
calc: 27
user: y
calc: 5
user: x + 2*y
calc: 37
The lexical analyzer returns VARIABLE and INTEGER tokens.
For variables, yylval
specifies an index to sym, our symbol table. For this program,
sym merely holds the
value of the associated variable. When INTEGER tokens are
returned, yylval contains
the number scanned. Here is the input specification for lex:
69. %%
int yywrap(void) {
return 1;
}
The input specification for yacc follows. The tokens for
INTEGER and VARIABLE are
utilized by yacc to create #defines in y.tab.h for use in lex. This
is followed by
definitions for the arithmetic operators. We may specify %left,
for left-associative, or
%right, for right associative. The last definition listed has the
highest precedence. Thus,
multiplication and division have higher precedence than
addition and subtraction. All
four operators are left-associative. Using this simple technique,
we are able to
disambiguate our grammar.
%token INTEGER VARIABLE
%left '+' '-'
%left '*' '/'
%{
int sym[26];
%}
19
%%
71. 20
4. Calculator
4.1 Description
This version of the calculator is substantially more complex
than previous versions.
Major changes include control constructs such as if-else and
while. In addition, a syntax
tree is constructed during parsing. After parsing, we walk the
syntax tree to produce
output. Two versions of the tree walk routine are supplied:
• an interpreter that executes statements during the tree walk,
and
• a compiler that generates code for a hypothetical stack-based
machine.
To make things more concrete, here is a sample program,
x = 0;
while (x < 3) {
print x;
x = x + 1;
}
with output for the interpretive version,
0
1
2
and output for the compiler version.
72. push 0
pop x
L000:
push x
push 3
compLT
jz L001
push x
print
push x
push 1
add
pop x
jmp L000
L001:
21
The include file contains declarations for the syntax tree and
symbol table. The
symbol table, sym, allows for single-character variable names.
A node in the syntax tree
may hold a constant (conNodeType), an identifier
(idNodeType), or an internal node
with an operator (oprNodeType). Union nodeType encapsulates
all three variants, and
nodeType.type is used to determine which structure we have.
The lex input file contains patterns for VARIABLE and
INTEGER tokens. In addition,
tokens are defined for 2-character operators such as EQ and NE.
73. Single-character
operators are simply returned as themselves.
The yacc input file defines YYSTYPE, the type of yylval, as
%union {
int iValue; /* integer value */
char sIndex; /* symbol table index */
nodeType nPtr; /* node pointer */
};
This causes the following to be generated in y.tab.h:
typedef union {
int iValue; /* integer value */
char sIndex; /* symbol table index */
nodeType nPtr; /* node pointer */
} YYSTYPE;
extern YYSTYPE yylval;
Constants, variables, and nodes can be represented by yylval in
the parser’s value stack.
Notice the type definitions
%token <iValue> INTEGER
%type <nPtr> expr
This binds expr to nPtr, and INTEGER to iValue in the
YYSTYPE union. This is
required so that yacc can generate the correct code. For
example, the rule
expr: INTEGER { $$ = con($1); }
74. should generate the following code. Note that yyvsp[0]
addresses the top of the value
stack, or the value associated with INTEGER.
yylval.nPtr = con(yyvsp[0].iValue);
22
The unary minus operator is given higher priority than binary
operators as follows:
%left GE LE EQ NE '>' '<'
%left '+' '-'
%left '*' '/'
%nonassoc UMINUS
The %nonassoc indicates no associativity is implied. It is
frequently used in conjunction
with %prec to specify precedence of a rule. Thus, we have
expr: '-' expr %prec UMINUS { $$ = node(UMINUS, 1, $2); }
indicating that the precedence of the rule is the same as the
precedence of token UMINUS.
And, as defined above, UMINUS has higher precedence than the
other operators. A similar
technique is used to remove ambiguity associated with the if-
else statement (see If-Else
Ambiguity, p. 35).
The syntax tree is constructed bottom-up, allocating the leaf
nodes when variables
and integers are reduced. When operators are encountered, a
node is allocated and
75. pointers to previously allocated nodes are entered as operands.
As statements are reduced,
ex is called to do a depth-first walk of the syntax tree. Since the
tree was constructed
bottom-up, a depth-first walk visits nodes in the order that they
were originally allocated.
This results in operators being applied in the order that they
were encountered during
parsing. Two versions of ex, an interpretive version, and a
compiler version, are
included.
23
4.2 Include File
typedef enum { typeCon, typeId, typeOpr } nodeEnum;
/* constants */
typedef struct {
nodeEnum type; /* type of node */
int value; /* value of constant */
} conNodeType;
/* identifiers */
typedef struct {
nodeEnum type; /* type of node */
int i; /* subscript to ident array */
} idNodeType;
76. /* operators */
typedef struct {
nodeEnum type; /* type of node */
int oper; /* operator */
int nops; /* number of operands */
union nodeTypeTag *op[1]; /* operands (expandable) */
} oprNodeType;
typedef union nodeTypeTag {
nodeEnum type; /* type of node */
conNodeType con; /* constants */
idNodeType id; /* identifiers */
oprNodeType opr; /* operators */
} nodeType;
extern int sym[26];
24
4.3 Lex Input
%{
#include <stdlib.h>
#include "calc3.h"
#include "y.tab.h"
%}
%%
[a-z] {
yylval.sIndex = *yytext - 'a';
87. case '+': printf("taddn"); break;
case '-': printf("tsubn"); break;
case '*': printf("tmuln"); break;
case '/': printf("tdivn"); break;
case '<': printf("tcompLTn"); break;
case '>': printf("tcompGTn"); break;
case GE: printf("tcompGEn"); break;
case LE: printf("tcompLEn"); break;
case NE: printf("tcompNEn"); break;
case EQ: printf("tcompEQn"); break;
}
}
}
}
32
5. More Lex
5.1 Strings
Quoted strings frequently appear in programming languages.
Here is one way to match a
string in lex:
%{
char *yylval;
#include <string.h>
%}
%%
"[^"n]*["n] {
88. yylval = strdup(yytext+1);
if (yylval[yyleng-2] != '"')
warning("improperly terminated string");
else
yylval[yyleng-2] = 0;
printf("found '%s'n", yylval);
}
The above example ensures that strings don’t cross line
boundaries, and removes
enclosing quotes. If we wish to add escape sequences, such as n
or ", start states
simplify matters:
%{
char buf[100];
char *s;
%}
%x STRING
%%
" { BEGIN STRING; s = buf; }
<STRING>n { *s++ = 'n'; }
<STRING>t { *s++ = 't'; }
<STRING>" { *s++ = '"'; }
<STRING>" {
*s = 0;
BEGIN 0;
printf("found '%s'n", buf);
}
89. <STRING>n { printf("invalid string"); exit(1); }
<STRING>. { *s++ = *yytext; }
Exclusive start state STRING is defined in the definition
section. When the scanner
detects a quote, the BEGIN macro shifts lex into the STRING
state. Lex stays in the
STRING state, recognizing only patterns that begin with
<STRING>, until another BEGIN
33
is executed. Thus, we have a mini-environment for scanning
strings. When the trailing
quote is recognized, we switch back to state 0, the initial state.
5.2 Reserved Words
If your program has a large collection of reserved words, it is
more efficient to let lex
simply match a string, and determine in your own code whether
it is a variable or
reserved word. For example, instead of coding
"if" return IF;
"then" return THEN;
"else" return ELSE;
{letter}({letter}|{digit})* {
yylval.id = symLookup(yytext);
return IDENTIFIER;
}
where symLookup returns an index into the symbol table, it is
90. better to detect reserved
words and identifiers simultaneously, as follows:
{letter}({letter}|{digit})* {
int i;
if ((i = resWord(yytext)) != 0)
return (i);
yylval.id = symLookup(yytext);
return (IDENTIFIER);
}
This technique significantly reduces the number of states
required, and results in smaller
scanner tables.
5.3 Debugging Lex
Lex has facilities that enable debugging. This feature may vary
with different versions of
lex, so you should consult documentation for details. The code
generated by lex in file
lex.yy.c includes debugging statements that are enabled by
specifying command-line
option “-d”. Debug output may be toggled on and off by setting
yy_flex_debug.
Output includes the rule applied and corresponding matched
text. If you’re running lex
and yacc together, specify the following in your yacc input file:
extern int yy_flex_debug;
int main(void) {
yy_flex_debug = 1;
yyparse();
91. }
34
Alternatively, you may write your own debug code by defining
functions that display
information for the token value, and each variant of the yylval
union. This is illustrated
in the following example. When DEBUG is defined, the debug
functions take effect, and a
trace of tokens and associated values is displayed.
%union {
int ivalue;
...
};
%{
#ifdef DEBUG
int dbgToken(int tok, char *s) {
printf("token %sn", s);
return tok;
}
int dbgTokenIvalue(int tok, char *s) {
printf("token %s (%d)n", s, yylval.ivalue);
return tok;
}
#define RETURN(x) return dbgToken(x, #x)
92. #define RETURN_ivalue(x) return dbgTokenIvalue(x, #x)
#else
#define RETURN(x) return(x)
#define RETURN_ivalue(x) return(x)
#endif
%}
%%
[0-9]+ {
yylval.ivalue = atoi(yytext);
RETURN_ivalue(INTEGER);
}
"if" RETURN(IF);
"else" RETURN(ELSE);
35
6. More Yacc
6.1 Recursion
When specifying a list, we may do so using left recursion,
list:
item
| list ',' item
;
or right recursion:
93. list:
item
| item ',' list
If right recursion is used, all items on the list are pushed on the
stack. After the last item
is pushed, we start reducing. With left recursion, we never have
more than three terms on
the stack, since we reduce as we go along. For this reason, it is
advantageous to use left
recursion.
6.2 If-Else Ambiguity
A shift-reduce conflict that frequently occurs involves the if-
else construct. Assume we
have the following rules:
stmt:
IF expr stmt
| IF expr stmt ELSE stmt
...
and the following state:
IF expr stmt IF expr stmt . ELSE stmt
We need to decide if we should shift the ELSE, or reduce the IF
expr stmt at the top
of the stack. If we shift, then we have
IF expr stmt IF expr stmt . ELSE stmt
IF expr stmt IF expr stmt ELSE . stmt
IF expr stmt IF expr stmt ELSE stmt .
IF expr stmt stmt .
where the second ELSE is paired with the second IF. If we
94. reduce, we have
36
IF expr stmt IF expr stmt . ELSE stmt
IF expr stmt stmt . ELSE stmt
IF expr stmt . ELSE stmt
IF expr stmt ELSE . stmt
IF expr stmt ELSE stmt .
where the second ELSE is paired with the first IF. Modern
programming languages pair
an ELSE with the most recent unpaired IF, so the former
behavior is expected. This
works well with yacc, since default behavior, when a shift-
reduce conflict is encountered,
is to shift.
Although yacc does the right thing, it also issues a shift-reduce
warning message. To
remove the message, give IF-ELSE a higher precedence than the
simple IF statement:
%nonassoc IFX
%nonassoc ELSE
stmt:
IF expr stmt %prec IFX
| IF expr stmt ELSE stmt
6.3 Error Messages
A nice compiler gives the user meaningful error messages. For
example, not much
information is conveyed by the following message:
95. syntax error
If we track the line number in lex, then we can at least give the
user a line number:
void yyerror(char *s) {
fprintf(stderr, "line %d: %sn", yylineno, s);
}
When yacc discovers a parsing error, default action is to call
yyerror, and then return
from yylex with a return value of one. A more graceful action
flushes the input stream
to a statement delimiter, and continues to scan:
stmt:
';'
| expr ';'
| PRINT expr ';'
| VARIABLE '=' expr ';
| WHILE '(' expr ')' stmt
| IF '(' expr ')' stmt %prec IFX
| IF '(' expr ')' stmt ELSE stmt
| '{' stmt_list '}'
| error ';'
| error '}'
;
37
The error token is a special feature of yacc that will match all
input until the token
96. following error is found. For this example, when yacc detects an
error in a statement it
will call yyerror, flush input up to the next semicolon or brace,
and resume scanning.
6.4 Inherited Attributes
The examples so far have used synthesized attributes. At any
point in a syntax tree we can
determine the attributes of a node based on the attributes of its
children. Consider the rule
expr: expr '+' expr { $$ = $1 + $3; }
Since we are parsing bottom-up, the values of both operands are
available, and we can
determine the value associated with the left-hand side. An
inherited attribute of a node
depends on the value of a parent or sibling node. The following
grammar defines a C
variable declaration:
decl: type varlist
type: INT | FLOAT
varlist:
VAR { setType($1, $0); }
| varlist ',' VAR { setType($3, $0); }
Here is a sample parse:
. INT VAR
INT . VAR
type . VAR
type VAR .
type varlist .
decl .
97. When we reduce VAR to varlist, we should annotate the symbol
table with the type of
the variable. However, the type is buried in the stack. This
problem is resolved by
indexing back into the stack. Recall that $1 designates the first
term on the right-hand
side. We can index backwards, using $0, $-1, and so on. In this
case, $0 will do just
fine. If you need to specify a token type, the syntax is
$<tokentype>0, angle brackets
included. In this particular example, care must be taken to
ensure that type always
precedes varlist.
6.5 Embedded Actions
Rules in yacc may contain embedded actions:
list: item1 { do_item1($1); } item2 { do_item2($3); } item3
Note that the actions take a slot in the stack, so do_item2 must
use $3 to reference
item2. Actually, this grammar is transformed by yacc into the
following:
38
list: item1 _rule01 item2 _rule02 item3
_rule01: { do_item1($0); }
_rule02: { do_item2($0); }
6.6 Debugging Yacc
Yacc has facilities that enable debugging. This feature may vary
with different versions
98. of yacc, so you should consult documentation for details. The
code generated by yacc in
file y.tab.c includes debugging statements that are enabled by
defining YYDEBUG and
setting it to a non-zero value. This may also be done by
specifying command-line option
“-t”. With YYDEBUG properly set, debug output may be
toggled on and off by setting
yydebug. Output includes tokens scanned and shift/reduce
actions.
%{
#define YYDEBUG 1
%}
%%
...
%%
int main(void) {
#if YYDEBUG
yydebug = 1;
#endif
yylex();
}
In addition, you can dump the parse states by specifying
command-line option "-v".
States are dumped to file y.output, and are often useful when
debugging a grammar.
Alternatively, you can write your own debug code by defining a
TRACE macro, as
illustrated below. When DEBUG is defined, a trace of
reductions, by line number, is
displayed.
99. %{
#ifdef DEBUG
#define TRACE printf("reduce at line %dn", __LINE__);
#else
#define TRACE
#endif
%}
%%
statement_list:
statement
{ TRACE $$ = $1; }
| statement_list statement
{ TRACE $$ = newNode(';', 2, $1, $2); }
;
39
7. Bibliography
Aho, Alfred V., Ravi Sethi and Jeffrey D. Ullman [1986].
Compilers, Prinicples,
Techniques and Tools. Addison-Wesley, Reading,
Massachusetts.
Gardner, Jim, Chris Retterath and Eric Gisin [1988]. MKS Lex
& Yacc. Mortice Kern
Systems Inc., Waterloo, Ontario, Canada.
Johnson, Stephen C. [1975]. Yacc: Yet Another Compiler
Compiler. Computing Science
100. Technical Report No. 32, Bell Laboratories, Murray hill, New
Jersey.
Lesk, M. E. and E. Schmidt [1975]. Lex – A Lexical Analyzer
Generator. Computing
Science Technical Report No. 39, Bell Laboratories, Murray
Hill, New Jersey.
Levine, John R., Tony Mason and Doug Brown [1992]. Lex &
Yacc. O’Reilly &
Associates, Inc. Sebastopol, California.
http://www.amazon.com/exec/obidos/ISBN=0201100886/none01
A/
http://www.amazon.com/exec/obidos/ISBN=0201100886/none01
A/
http://members.xoom.com/thomasn/y_yacc.pdf
http://members.xoom.com/thomasn/y_lex.pdf
http://www.amazon.com/exec/obidos/ISBN=1565920007/none01
A/PrefaceIntroductionLexTheoryPracticeYaccTheoryPractice,
Part IPractice, Part IICalculatorDescriptionInclude FileLex
InputYacc InputInterpreterCompilerMore LexStringsReserved
WordsDebugging LexMore YaccRecursionIf-Else
AmbiguityError MessagesInherited AttributesEmbedded
ActionsDebugging YaccBibliography
cmparser.y
%{
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include "ast.h"
#include "symbolTable.h"
#include "util.h"
101. /* other external function prototypes */
extern int yylex();
extern int initLex(int , char **);
extern AstNodePtr new_Node(NodeKind kind);
/* external global variables */
extern int yydebug;
extern int yylineno;
extern SymbolTableStackEntryPtr symbolStackTop;
extern int scopeDepth;
/* function prototypes */
void yyerror(const char *);
/* global variables */
AstNodePtr program;
FILE *outfile;
%}
/* YYSTYPE */
%union
{
AstNodePtr nodePtr;
int iVal;
char *cVal;
Type *type;
}
/* terminals */