• Applications programming language.
• Productivity and developing high quality solutions that can scale.
• Small and flexible language that can be embedded in C/C++ projects.
• Simple language that can be used in education and introducing Compiler/VM concepts.
• General-Purpose language that can be used for creating domain-specific libraries, frameworks and tools.
• Practical language designed for creating the next version of the Programming Without Coding Technology software.

Ring is a very simple language, and has a very straightforward syntax. It encourages programmers to program without boilerplate code.
To print something using the standard output, We can use the 'See' command.

see "Hello, World!" 
			

The Main function is optional and will be executed after the statements, and is useful for using the local scope.

func main
	see "Hello, World!" 
			

Uses Dynamic Typing and Lexical scoping.
Also we can use the '+' operator for string concatenation.

nCount = 10	# Global variable
func main
	nID = 1	# Local variable
	see "Count = " + nCount + nl + " ID = " + nID
			

Ring is not case-sensitive

see "Enter your name ? " 
give name
see "Hello " + Name	# Name is the same as name 
			

The list index starts from 1

aList = ["one","two","three"]
see aList[1]	# print one
			

Call functions before definition

one() 
two() 
three()
func one 
	see "One" 
func two 
	see "two" 
func three 
	see "three" 
			

The assignment operator uses Deep copy (no references in this operation)

aList = ["one","two","three"]
aList2 = aList
aList[1] = 1
see alist[1]	# print 1
see aList2[1]	# print one
			

Pass numbers and strings by value, but pass lists and objects by reference.
The for in loop can update the list items.

func main
	aList = [1,2,3]
	update(aList)
	see aList	# print one two three

func update aList
	for x in aList
		switch x
		on 1 x = "one"
		on 2 x = "two"
		on 3 x = "three"
		off
	next
			

Using Lists during definition

aList = [ [1,2,3,4,5] , aList[1] , aList[1] ]
see aList       # print 1 2 3 4 5 1 2 3 4 5 1 2 3 4 5
			

Exit from more than one loop

for x = 1 to 10
        for y = 1 to 10
                see "x=" + x + " y=" + y + nl
                if x = 3 and y = 5
                        exit 2     # exit from 2 loops
                ok
        next
next
			

The language encourage organization, Forget bad days using languages where the programmer start with function then class then function and a strange mix between things!

Each source file follow the next structure

• Load Files
• Statements and Global Variables
• Functions
• Packages and Classes

This enable us to use Packages, Classes and Functions without the need to use a keyword to end these components.

We can write one line comments and multi-line comments
The comment starts with # or //
Multi-line comments are written between /* and */

/* 
	Program Name : My first program using Ring
	Author       : Ring Team 
*/

see "What is your name? " 	# print message on screen
give cName 			# get input from the user
see "Hello " + cName		# say hello!

// See "End of Program!"
			

Ring contains only four (4) types that represent the program data. These types are (String, Number, List & Object). The idea is to have many use cases for each type which increase the flexibility and the ability to write functions that are more usable in different situations.

The String type is used to represent:

• One character
• A string of many characters
• Multi-line string
• Binary Data

cStr1 = "a"			# One character
cStr2 = "Hello, World!" 	# A string of many characters
cStr3 = "Hello
Welcome to the Ring language!
"				# Multi-line string
cStr4 = read(EXEFileName())	# Read executable file (Binary Data)

The Number type is used to represent

• Boolean Values
• Signed/Unsigned Integers
• Float/Double

nNum1 = True		# Boolean Value (1)
nNum2 = False		# Boolean Value (0)
nNum3 = 10		# Integer
nNum4 = -10		# Signed Integer
nNum5 = 1250.11		# Float/Double

The List type is used instead of

• One Dimension Arrays
• Multi-Dimension Arrays
• Lists of multiple types
• Nested Lists
• Hash Tables (Key & Value)
• Tree
• Wrapper around a C Pointer

aList1 = ["one","two","three"]				# Strings
aList2 = [1,2,3,4,5,6,7,8,9,10]				# Numbers
aList3 = ["Ring",1234]					# Multiple types
aList4 = [["Fayed","Egypt"],["Mansour","Tunisia"]]  	# Nested Lists
aList5 = [ :name = "Fayed", :country = "Egypt"]		# Hash Tables

The Object type is used to represent objects created from classes

Using classes and operator overloading we can create custom types

The language is not line sensitive, you don't need to write ; after statements, also you don't need to press ENTER or TAB, so we can write the next code

see "The First Message"	see " Another message in the same line! " + nl
see "Enter your name?" give Name see "Hello " + Name
			

The next code create a class called Point contains three attributes X,Y and Z. No keywords is used to end the package/class/function definition. Also, we can write the attributes names directly below the class name.

class Point X Y Z
			

We can use classes and functions before their definition, In this example we will create new object, set the object attributes then print the object values.

o1 = new point	o1.x=10    o1.y=20   o1.z=30	see O1	class Point X Y Z
			

Instead of using the dot '.' operator to access the object attributes and methods we can use braces { } to access the object, then we can use the object attributes and methods.

 
o1 = new point { x=10 y=20 z=30 } see O1  class Point X Y Z
			 

Now we will call a method after accessing the object using { }

 
oPerson = new Person
{
	Name = "Somebody"
	Address = "Somewhere"
	Phone = "0000000"
	Print()			# here we call the Print() method
}
class Person Name Address Phone
	func Print
		see "Name :" + name + nl +
		    "Address :" + Address + nl +
		    "Phone : " + phone + nl

When we use { } to access the object then write any attribute name, the language will check the class for any setter/getter methods that will be called automatically.

new Number {
		see one		# Execute GetOne()
		see two		# Execute GetTwo()
		see three	# Execute GetThree()
}
class Number one two three
	func GetOne
		see "Number : One" + nl
		return 1
	func GetTwo
		see "Number : Two" + nl
		return 2
	func GetThree
		see "Number : Three" + nl
		return 3	

Ring comes with many styles for writing your source code. Also, You can change the language keywords and operators and create your custom style!

• The First Style



? "Welcome to Ring! "
new test { start() }

class Test
	x=10  y=20
	func start 
		? "x+y=" + (x+y)
		for t=1 to 10 
			? "t = " + t
			if t=3 
				? "Three" 
			ok
		next

• The Second Style



def main
	put "Welcome to Ring! " + nl
	new test { start() }
end

class Test
	x = 10
	y = 20
	def start 
		put "x+y=" + (x+y) + nl
		for t=1 to 10 
			put "t = " + t + nl
			if t=3 
				put "Three" + nl
			end
		end
	end
end

• The Third Style



load "stdlib.ring"

func main() {
	print("Welcome to Ring! \n")
	new test { start() }
}

class Test {
	x = 10
	y = 20
	func start {
		print("x+y=" + (x+y) + "\n")
		for t=1 to 10 {
			print("t = " + t + " \n")
			if t=3 {
				print("Three \n")
			}
		}
	}
}

• Change Keywords



ChangeRingKeyword See Print
Print "Hello, World!"
ChangeRingKeyword Print See
See "Hello, World!"
ChangeRingKeyword See Show
Show "Hello, World!"

After the object access using { } if the class contains a method called BraceEnd() it will be executed!

TimeForFun = new journey
# The first surprise!
TimeForFun {
	Hello it is me		# What a beautiful programming world!
}
# Our Class
class journey
	hello it is me
	func GetHello
		? "Hello" 
	func braceEnd
		? "Goodbye!"	

We can execute code written in strings using the Eval() function

cCode = "See 'Code that will be executed later!' "
Eval(cCode)	# execute the code to print the message

We can create a list then execute code generated from that list

aWords = ["hello","it","is","me"]
for word in aWords cCode=word+"=0" eval(cCode) next

We can read text files using the Read(cFileName) function and we can write files using the Write(cFileName,cString) function.

see "Enter File Name:" give cFileName see read(cFileName) # Print the file content

The next example presents how to create a class that defines two instructions
The first instruction is : I want window
The second instruction is : Window title = Expression
Also keywords that can be ignored like the **the** keyword

new App
{
        I want window
        The window title = "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
			nWindowTitle = 0
	# Keywords to ignore
			the

        func geti
                if nIwantwindow = 0
                        nIwantwindow++
                ok

        func getwant
                if nIwantwindow = 1
                        nIwantwindow++
                ok

        func getwindow
                if nIwantwindow = 2
                        nIwantwindow= 0
                        ? "Instruction : I want window"
                ok
                if nWindowTitle = 0
                        nWindowTitle++
                ok

        func settitle cValue
                if nWindowTitle = 1
                        nWindowTitle=0
                        ? "Instruction : Window Title = " + cValue 
                ok

        

To complete the previous example, use read() to get the content of a file that contains

        I want window
        The window title = "hello world"

Then use eval() to execute the content of that file!.
Also, you can update the methods GetWindow() and SetTitle() to create Real windows using the GUI Library

We learned how to use Natural statements to execute our code and using the same features we can use nested structures to execute our code.

The next example from the Web library, generate HTML document using the Bootstrap library. No HTML code is written directly in this example, we created a similar language (just as example) Then using this declarative language that uses nested structures, we generated the HTML Document..
The idea in this example is that the GetDiv() and GetH1() methods return an object that we can access using {} and after each object access the method BraceEnd() will be executed to send the generated HTML to the parent object until we reach to the root where BraceEnd() will print the output.

load "weblib.ring"
import System.Web

func Main

  BootStrapWebPage()
  {
        div
        {
          classname = :container
          div
          {
                classname = :jumbotron
                H1 {   text("Bootstrap Page")   }
          }
          div
          {
                classname = :row
                for x = 1 to 3
                  div
                  {
                        classname = "col-sm-4"
                        H3 { html("Welcome to the Ring programming language") }
                        P  { html("Using a scripting language is very fun!") }
                  }
                next
          }
        }
  }

The classes that power the declarative interface looks like this

	class Link from ObjsBase
		title  link
		func braceend			
			cOutput = nl+GetTabs() + "<a href='" + 
				  Link + "'> "+ Title + " </a> " + nl			

	class Div from ObjsBase 
		func braceend
			cOutput += nl+'<div'
			addattributes()
			AddStyle()
			getobjsdata()
			cOutput += nl+"</div>" + nl
			cOutput = TabMLString(cOutput)
	 

Ring comes with transparent implementation. We can know what is happening in each compiler stage and what is going on during the run-time by the Virtual Machine Example : ring helloworld.ring -tokens -rules -ic -norun

see "Hello, World!" 
			

Output

==================================================================
Tokens - Generated by the Scanner
==================================================================

   Keyword : SEE
   Literal : Hello, World!
   EndLine

==================================================================

==================================================================
Grammar Rules Used by The Parser
==================================================================

Rule : Program --> {Statement}

Line 1
Rule : Factor --> Literal
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  --> 'See' Expr

==================================================================

==================================================================
Byte Code - Before Execution by the VM
==================================================================

     PC      OPCode        Data
      1     FuncExE
      2       PushC   Hello, World!
      3       Print
      4  ReturnNull

==================================================================
			

The Ring programming language is designed using the PWCT visual programming tool

Avoid memory problems :-

• Invalid Memory Access
• Memory leaks
• Uninitialized Memory Access
• Dangling pointer

Rules :-

• Global variables always stay in the memory, until you delete these variables using the assignment statement.
• Local variables always deleted after the end of the function.
• The programmer have full control on when to delete the variable from the memory using the Assignment statement.

Example:

aList = [1,2,3,4,5]
aList = "nice"
			

After the second line directly, The list [1,2,3,4,5] will be deleted from the memory and we will have a string "nice"


• The programmer can call the function callgc() to force running the garbage collector.
• If we have a reference to a variable (when we pass objects and lists to functions), then deleting variables will be based on reference counting, if no references everything will be deleted, but if we have a reference, the data will stay in memory.

When we use threads in Ring applications, We don't have global interpreter (VM) lock (No GIL)

So threads can work in parallel and execute Ring instructions at the same time

This is better for threads and concurrency (More Faster!)