The Ring programming language version 1.10 book - Part 49 of 212

1. Ring Documentation, Release 1.10
start
Hello
end
start
end
51.8 BraceExprEval Method
The next example demonstrates how to use the “BraceExprEval” method to get expressions in Natural code.
Example:
new natural {
create 5
}
class natural
create=0
lkeyword = false
func braceexpreval r
if lkeyword lkeyword=false return ok
see "expr eval" + nl
see "type: " + type(r) see nl
see "value : " see r see nl
func getcreate
lkeyword = true
see "create" + nl
Output:
create
expr eval
type: NUMBER
value : 5
51.9 Real Natural Code
The next example is a more advanced example
# Natural Code
new program {
Accept 2 numbers then print the sum
}
# Natural Code Implementation
class program
# Keywords
Accept=0 numbers=0 then=0 print=0 the=0 sum=0
# Execution
func braceexpreval x
value = x
func getnumbers
for x=1 to value
see "Enter Number ("+x+") :" give nNumber
51.8. BraceExprEval Method 448

2. Ring Documentation, Release 1.10
aNumbers + nNumber
next
func getsum
nSUm = 0
for x in aNumbers nSum+= x next
see "The Sum : " + nSum
private
value=0 aNumbers=[]
Output:
Enter Number (1) :3
Enter Number (2) :4
The Sum : 7
51.10 BraceError() Method
The next examples demonstrates how to use the “BraceError” method to handle errors when accessing the object using
braces {}.
Example:
func main
o1 = new point {
x=10 y=20 z=30
TEST
SEE test
}
class point x y z
func braceerror
see "Handle Error!" + nl
SEE "Message :" + cCatchError + nl
if ( left(cCatchError,11) = "Error (R24)" ) and not isattribute(self,"test")
see "add attribute" + nl
addattribute(self,"test")
test = 10
ok
see "done" + nl
return
Output:
Handle Error!
Message :Error (R24) : Using uninitialized variable : test
add attribute
done
10
Example:
new point {
x=10 y=20 z=30
test()
see "mmm..." + NL
}
51.10. BraceError() Method 449

3. Ring Documentation, Release 1.10
class point x y z
func braceerror
see "Handle Error!" + nl
see "Message :" + cCatchError + nl
see self
see "Done" + NL
Output:
Handle Error!
Message :Error (R3) : Calling Function without definition !: test
x: 10.000000
y: 20.000000
z: 30.000000
Done
mmm...
51.11 Clean Natural Code
Instead of typing the literal as “literal” we can accept the words directly.
Example:
The next example accept hello world instead of “hello world”
But this example uses braceend() to check the end of the instruction
This means that this class process only one natural statement that end with literal.
ChangeRingKeyword and _and
New App
{
I want window and the window title is hello world
}
Class App
# Attributes for the instruction I want window
i want window
nIwantwindow = 0
# Attributes for the instruction Window title
# Here we don't define the window attribute again
title is
nWindowTitle = 0
# Keywords to ignore, just give them any value
the=0 and=0
# Data
literal = ""
ChangeRingKeyword _and and
func geti
if nIwantwindow = 0
nIwantwindow++
ok
func getwant
51.11. Clean Natural Code 450

4. Ring Documentation, Release 1.10
if nIwantwindow = 1
nIwantwindow++
ok
func getwindow
if nIwantwindow = 2
nIwantwindow= 0
see "Instruction : I want window" + nl
ok
if nWindowTitle = 0
nWindowTitle++
ok
func gettitle
if nWindowTitle = 1
nWindowTitle=2
ok
func getis
if nWindowTitle = 2
nWindowTitle=3
ok
func braceend
if nWindowTitle = 3
see "Instruction : Window Title = " + literal + nl
nWindowTitle = 0
ok
func braceerror
c= substr(cCatchError,":")
while c > 0
c= substr(cCatchError,":")
cCatchError=substr(cCatchError,c+1)
end
literal += substr(cCatchError,1)
51.11. Clean Natural Code 451

5. CHAPTER
FIFTYTWO
USING THE NATURAL LIBRARY
In this chapter we will learn how to use the Natural Library to quickly define a language that contains a group of
commands.
To start using the library, We need to call naturallib.ring
load "naturallib.ring"
After loading the library, We can use the NaturalLanguage class that contains the next methods :-
• SetLanguageName(cLanguageName)
• setCommandsPath(cFolder)
• SetPackageName(cPackageName)
• UseCommand(cCommandName)
• SetOperators(cOperators)
• RunFile(cFileName)
• RunString(cString)
52.1 Natural Library - Demo Program
We will write the natural code in a Text file, for example program.txt
File: program.txt
Welcome to the Ring programming language!
What you are reading now is not comments, I swear!
After many years of programming I decided to think different about
programming and solve the problems in a better way.
We are writing commands or code and the Ring language is reading
it to understand us! Sure, What you are seeing now is
just ***part of the code - Not the Complete Program***
You have to write little things before and after this
part to be able to run it!
It is the natural part of our code where we can write in English,
Arabic or any Natural Language Then we will tell the computer
through the Ring language what must happens! in a way that we can scale
for large frameworks and programs.
452

6. Ring Documentation, Release 1.10
Just imagine what will happens to the world of programming once
we create many powerful frameworks using the Ring language that
uses this way (Natural Programming).
For example When we say Hello to the Machine, It can reply! and when we
say count from 1 to 5 it will understand us, Also if
we said count from 5 to 1 it will
understand us too! You can see the Output window!
This Goal is not new, but the Ring language comes
with an innovative solution to this problem.
Output:
Hello, Sir!
The Numbers!
1
2
3
4
5
I will count Again!
5
4
3
2
1
To execute the natural code, We have start.ring
In start.ring we define the language and the commands.
File: start.ring
load "stdlib.ring"
load "naturallib.ring"
New NaturalLanguage {
SetLanguageName(:MyLanguage)
SetCommandsPath(CurrentDir()+"/../command")
SetPackageName("MyLanguage.Natural")
UseCommand(:Hello)
UseCommand(:Count)
RunFile("program.txt")
}
We defined a language called MyLanguage, We have folder for the language commands.
52.1. Natural Library - Demo Program 453

7. Ring Documentation, Release 1.10
Each command will define a class that belong to the MyLanguage.Natural package.
We will define two commands, Hello and Count.
So we must have two files for defining the commands in the CurrentDir()+”/../command” folder
File: hello.ring
DefineNaturalCommand.SyntaxIsKeyword([
:Package = "MyLanguage.Natural",
:Keyword = :hello,
:Function = func {
See "Hello, Sir!" + nl + nl
}
])
File: count.ring
DefineNaturalCommand.SyntaxIsKeywordNumberNumber([
:Package = "MyLanguage.Natural",
:Keyword = :count,
:Function = func {
if not isattribute(self,:count_times) {
AddAttribute(self,:count_times)
Count_Times = 0
}
if Expr(1) > Expr(2) {
nStep = -1
else
nStep = 1
}
if Count_Times = 0 {
see nl+"The Numbers!" + nl
Count_Times++
else
see nl + "I will count Again!" +nl
}
for x = Expr(1) to Expr(2) step nStep {
see nl+x+nl
}
CommandReturn(fabs(Expr(1)-Expr(2))+1)
}
])
52.2 Defining Commands
To define new command we can use the DefineNaturalCommand object
This object provides the next methods :-
• SyntaxIsKeyword(aPara)
• SyntaxIsKeywordNumber(aPara)
• SyntaxIsKeywordNumberNumber(aPara)
• SyntaxIsKeywordNumbers(aPara,nCount)
• SyntaxIsKeywordString(aPara)
• SyntaxIsKeywordStringString(aPara)
52.2. Defining Commands 454

8. Ring Documentation, Release 1.10
• SyntaxIsKeywordStrings(aPara,nCount)
• SyntaxIsKeywordExpression(aPara)
• SyntaxIsKeywordExpressionExpression(aPara)
• SyntaxIsKeywordExpressions(aPara,nCount)
• SyntaxIsCommand(aPara)
• SyntaxIsCommandNumber(aPara)
• SyntaxIsCommandNumberNumber(aPara)
• SyntaxIsCommandNumbers(aPara,nCount)
• SyntaxIsCommandString(aPara)
• SyntaxIsCommandStringString(aPara)
• SyntaxIsCommandStrings(aPara,nCount)
• SyntaxIsCommandExpression(aPara)
• SyntaxIsCommandExpressionExpression(aPara)
• SyntaxIsCommandExpressions(aPara,nCount)
File: mylanguage.ring
load "stdlib.ring"
load "naturallib.ring"
MyLanguage = New NaturalLanguage {
SetLanguageName(:MyLanguage)
setCommandsPath(CurrentDir()+"/../command")
SetPackageName("MyLanguage.Natural")
UseCommand(:Hello)
UseCommand(:Count)
UseCommand(:Print)
UseCommand(:IWantWindow)
UseCommand(:WindowTitleIs)
UseCommand(:IWantButton)
}
Example (1)
In the next example we will define the Print command.
We will use the SyntaxIsKeywordExpression() Method.
We pass list (as Hash) to the method. We determine the package name, the keyword and the function that will be
executed.
Inside this function we uses the Expr(nExprNumber) function to get the expression value that the user will write after
the keyword.
File: print.ring
DefineNaturalCommand.SyntaxIsKeywordExpression([
:Package = "MyLanguage.Natural",
:Keyword = :print,
:Function = func {
See Expr(1)
}
])
52.2. Defining Commands 455

9. Ring Documentation, Release 1.10
Usage:
load "mylanguage.ring"
MyLanguage.RunString('
print "Hello, World!"
')
Output:
Hello, World!
Example (2)
File: iwantwindow.ring
DefineNaturalCommand.SyntaxIsCommand([
:Package = "MyLanguage.Natural",
:Command = "i want window",
:Function = func {
See "Command: I want window" + nl
}
])
Usage:
load "mylanguage.ring"
MyLanguage.RunString('
i want window
')
Output:
Command: I want window
Example (3)
File: windowtitleis.ring
DefineNaturalCommand.SyntaxIsCommandString([
:Package = "MyLanguage.Natural",
:Command = "window title is",
:Function = func {
See "Command: Window title is " + Expr(1) + nl
}
])
Usage:
load "mylanguage.ring"
MyLanguage.RunString('
I want window and the window title is "Hello World"
')
Output:
Command: I want window
Command: Window title is Hello World
52.2. Defining Commands 456

10. Ring Documentation, Release 1.10
52.3 Natural Library - Operators
In the next example we uses the Count command without using operators
load "mylanguage.ring"
MyLanguage.RunString("
Hello
Count 1 5
Count 5 1
")
We can add more description
load "mylanguage.ring"
MyLanguage.RunString("
Hello, Please Count from 1 to 5 then count from 5 to 1
")
Also we can use operators like “(” and ”)” around the instruction
load "mylanguage.ring"
MyLanguage {
SetOperators("()")
RunString("
Here we will play and will try something
that looks like Lisp Syntax
(count (count 1 5) (count 20 15))
Just for fun!
")
}
52.4 Defining commands using classes
This section is related to the implementation details.
When we define new command, Each command is defined by the Natural Library as a class.
We have the choice to define commands using the simple interface provided by the DefineNaturalCommand object or
by defining new class as in the next examples.
If we used DefineNaturalCommand (More Simple), The class will be defined during the runtime.
File: hello.ring
Package MyLanguage.Natural
class Hello
func AddAttributes_Hello
AddAttribute(self,:hello)
func GetHello
See "Hello, Sir!" + nl + nl
File: count.ring
52.3. Natural Library - Operators 457