The Ring programming language version 1.7 book - Part 80 of 196

1. Ring Documentation, Release 1.7
65.16 Using ‘endpackage’/’endclass’/’endfunc’ keywords after Pack-
ages/Classes/Functions
Example:
import mypackage
new myclass { myfunc() }
package mypackage
class myclass
func myfunc
see "welcome" + nl
endfunc
endclass
endpackage
65.16. Using ‘endpackage’/’endclass’/’endfunc’ keywords after Packages/Classes/Functions 762

2. CHAPTER
SIXTYSIX
INTRODUCTION TO THE TYPE HINTS LIBRARY
In this chapter we will learn about the Type Hints Library
66.1 Why Type Hints?
Using this library we can add the type information to the source code which will be very useful for tools like
• Code Editors
• Static-Analysis
Note: Ring is a dynamic language, No type checking will be done by the compiler.
66.2 Example
The next example will use the Type Hints library
load "typehints.ring"
see sum(3,4) + nl ;
see sayHello("Mahmoud");
int func sum(int x,int y) {
return x+y ;
}
string func sayHello(string name) {
return "Hello " + name ;
}
66.3 User Types
The Type Hints library is very powerful and will support user types (Classes) automatically
Example:
load "typehints.ring"
import mypackage
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3. Ring Documentation, Release 1.7
test() { main([:one,:two,:three]) }
myclass func test() {
see "Testing User Types!" + nl
return new myclass
}
package mypackage {
public class myclass {
public static void func main(list args) {
see "welcome" + nl
see args
}
}
}
66.4 Using Types inside Code
Also you can use the types inside the code (not only the function prototype)
Example:
load "typehints.ring"
int sum = sum(3,4)
string msg = sayHello("Mahmoud")
see "Sum = " + sum + nl + msg + nl
int func sum(int x,int y) {
return x+y ;
}
string func sayHello(string name) {
return "Hello " + name ;
}
66.5 Rules
• To use the types in the function prototype you must use ‘(‘ and ‘)’ around parameters
• To use the types in the function code, You must set the variable value (Assignment).
The next types are defined by the library
# Low Level Types
char
unsigned
signed
int
short
long
float
66.4. Using Types inside Code 764

4. Ring Documentation, Release 1.7
double
void
# High Level Types
string
list
number
object
# Other
public
static
abstract
protected
override
66.5. Rules 765

5. CHAPTER
SIXTYSEVEN
COMMAND LINE OPTIONS
The ring language takes source code file (.ring) or the object file (.ringo) as input to execute, also the language provide
other options like
Option Description
-tokens Print a list of tokens in the source code file
-rules Print grammar rules applied on the tokens
-ic Print the intermediate byte code (before execution)
-icfinal Print the final byte code (after execution)
-cgi Print http response header before error messages
-norun Don’t run the program after compiling
-ins Print instruction operation code before execution
-performance Print clock before and after program execution
-go Generate Object File
-w Display Warnings
67.1 Printing Tokens
Example:
Func Main
See "Hello World" + nl
for x = 1 to 10
see x + nl
next
test()
func test
see "welcome" + nl
o1 = new point { x=10 y=20 z=30 }
see o1
class point x y z
Command:
ring test.ring -tokens -norun
Output:
===================================================
Tokens - Generated by the Scanner
===================================================
766

6. Ring Documentation, Release 1.7
Keyword : FUNC
Identifier : main
EndLine
Keyword : SEE
Literal : Hello World
Operator : +
Identifier : nl
EndLine
Keyword : FOR
Identifier : x
Operator : =
Number : 1
Keyword : TO
Number : 10
EndLine
Keyword : SEE
Identifier : x
Operator : +
Identifier : nl
EndLine
Keyword : NEXT
EndLine
Identifier : test
Operator : (
Operator : )
EndLine
Keyword : FUNC
Identifier : test
EndLine
Keyword : SEE
Literal : welcome
Operator : +
Identifier : nl
EndLine
Identifier : o1
Operator : =
Keyword : NEW
Identifier : point
Operator : {
Identifier : x
Operator : =
Number : 10
Identifier : y
Operator : =
Number : 20
Identifier : z
Operator : =
Number : 30
Operator : }
EndLine
Keyword : SEE
Identifier : o1
EndLine
Keyword : CLASS
Identifier : point
Identifier : x
Identifier : y
Identifier : z
67.1. Printing Tokens 767

7. Ring Documentation, Release 1.7
EndLine
===================================================
67.2 Printing Rules
Command:
ring test.ring -rules -norun
Output:
===================================================
Grammar Rules Used by The Parser
===================================================
Rule : Program --> {Statement}
Line 1
Rule : Statement --> 'Func' Identifier [ParaList]
Line 2
Rule : Factor --> Literal
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : Arithmetic --> Arithmetic + Arithmetic
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> 'See' Expr
Line 3
Rule : Factor --> Number
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Factor --> Number
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
67.2. Printing Rules 768

8. Ring Documentation, Release 1.7
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> 'For' Identifier '=' Expr to Expr ['step' Expr]
Line 4
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : Arithmetic --> Arithmetic + Arithmetic
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> 'See' Expr
Line 5
Rule : Next --> 'Next'
Line 6
Rule : Mixer -> '(' [Expr { ',' Expr} ] ')'
Line 8
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> Expr
Rule : Statement --> 'Func' Identifier [ParaList]
Line 9
Rule : Factor --> Literal
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : Arithmetic --> Arithmetic + Arithmetic
67.2. Printing Rules 769

9. Ring Documentation, Release 1.7
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> 'See' Expr
Line 10
Rule : Factor --> New Identifier {'.' Identifier }
Rule : Mixer --> '{' {Statement} BraceEnd
Rule : Factor --> Number
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Assignment -> '=' Expr
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> Expr
Rule : Factor --> Number
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Assignment -> '=' Expr
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
67.2. Printing Rules 770

10. Ring Documentation, Release 1.7
Rule : Expr --> LogicNot
Rule : Statement --> Expr
Rule : Factor --> Number
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Assignment -> '=' Expr
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> Expr
Rule : BraceEnd --> '}'
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Assignment -> '=' Expr
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
Rule : BitOrXOR --> BitAnd
Rule : Compare --> BitOrXOR
Rule : EqualOrNot --> Compare
Rule : LogicNot -> EqualOrNot
Rule : Expr --> LogicNot
Rule : Statement --> Expr
Line 11
Rule : Factor --> Identifier [ {Mixer} | Assignment | PlusPlus | MinusMinus]
Rule : Range --> Factor
Rule : Term --> Range
Rule : Arithmetic --> Term
Rule : BitShift --> Arithmetic
Rule : BitAnd --> BitShift
67.2. Printing Rules 771