The Ring programming language version 1.2 book - Part 9 of 84
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The document provides information about control structures in Ring programming language including branching statements like if and switch, and looping statements like while, for, and for in loops. If statements allow executing code conditionally based on an expression. Switch statements allow executing different code blocks based on the value of an expression. While and for loops allow repetitive execution of code. The for in loop iterates over elements in a list or string.
![Ring Documentation, Release 1.2
12.4 Using Sublime Text 2
Folder : ring/editor/sublime text 2
In the folder Sublime_Text_2 you will find the next three files
1 - ring.json-tmlanguage
2 - ring.sublime-build
3 - ring.tmlanguage
Just Copy the files to the next path
“C:Users{UserName}AppDataRoamingSublime Text 2PackagesUser”
The file ring.sublime-build includes the next line
“cmd”: [”B:ringbinring.exe”,”$file”],
You can modify it according to the ring.exe path in your machine
12.4. Using Sublime Text 2 60](https://image.slidesharecdn.com/81ringring-170217110427/85/The-Ring-programming-language-version-1-2-book-Part-9-of-84-1-320.jpg)
![CHAPTER
THIRTEEN
VARIABLES
To create a new variable, you just need to determine the variable name & value. The value will determine the variable
type and you can change the value to switch between the types using the same variable name.
Syntax:
<Variable Name> = <Value>
Tip: The operator ‘=’ is used here as an Assignment operator and the same operator can be used in conditions, but
for testing equality of expressions.
Note: The Variable will contains the real value (not a reference). This means that once you change the variable value,
the old value will be removed from memory (even if the variable contains a list or object).
13.1 Dynamic Typing
Ring is a dynamic programming language that uses Dynamic Typing.
x = "Hello" # x is a string
see x + nl
x = 5 # x is a number (int)
see x + nl
x = 1.2 # x is a number (double)
see x + nl
x = [1,2,3,4] # x is a list
see x # print list items
x = date() # x is a string contains date
see x + nl
x = time() # x is a string contains time
see x + nl
x = true # x is a number (logical value = 1)
see x + nl
x = false # x is a number (logical value = 0)
see x + nl
13.2 Deep Copy
We can use the assignment operator ‘=’ to copy variables. We can do that to copy values like strings & numbers. Also,
we can copy complete lists & objects. The assignment operator will do a complete duplication for us. This operation
called Deep Copy
62](https://image.slidesharecdn.com/81ringring-170217110427/85/The-Ring-programming-language-version-1-2-book-Part-9-of-84-3-320.jpg)
![Ring Documentation, Release 1.2
list = [1,2,3,"four","five"]
list2 = list
list = []
See list # print the first list - no items to print
See "********" + nl
See list2 # print the second list - contains 5 items
13.3 Weakly Typed
Ring is a weakly typed language, this means that the language can automatically convert between data types (like
string & numbers) when that conversion make sense.
Rules:
<NUMBER> + <STRING> --> <NUMBER>
<STRING> + <NUMBER> --> <STRING>
Note: The same operator ‘+’ can be used as an arithmetic operator or for string concatenation.
Example:
x = 10 # x is a number
y = "20" # y is a string
sum = x + y # sum is a number (y will be converted to a number)
Msg = "Sum = " + sum # Msg is a string (sum will be converted to a string)
see Msg + nl
13.3. Weakly Typed 63](https://image.slidesharecdn.com/81ringring-170217110427/85/The-Ring-programming-language-version-1-2-book-Part-9-of-84-4-320.jpg)
![Ring Documentation, Release 1.2
14.4 Bitwise Operators
The next table presents all of the bitwise operators provided by the Ring language. Assume variable X=8 and variable
Y=2 then:
Operator Description Example Result
& Binary AND x & y 0
| Binary OR x | y 10
^ Binary XOR x ^ y 10
~ Binary Ones Complement ~x -9
<< Binary Left Shift x << y 32
>> Binary Right Shift x >> y 2
14.5 Assignment Operators
The next table presents all of the assignment operators provided by the Ring language.
Assume variable X=8 then:
Operator Description Example Result
= Assignment x = 10 x=10
+= Add AND assignment x += 5 x=13
-= Subtract AND assignment x -= 3 x=5
*= Multiply AND assignment x *= 2 x=16
/= Divide AND assignment x /= 3 x=2.67
%= Modulus AND assignment x %= 2 x=0
<<= Left shift AND assignment x <<= 2 x=32
>>= Right shift AND assignment x >>= 2 x=2
&= Bitwise AND assignment x &= 4 x=0
|= Bitwise OR and assignment x |= 3 x=11
^= Bitwise XOR and assignment x ^= 4 x=12
14.6 Misc Operators
Operator Description
:literal using : before identifier mean literal
Start:End create list contains items from start to end
[list items] define list items
list[index] access list item
obj.name using the dot operator to access object members (attributes/methods).
obj {stmts} execute statements with direct access to object attributes & methods
func(para,...) call function using parameters separated by comma
14.7 Operators Precedence
The next table present operators from higher precedence (Evaluated first) to lower precedence.
14.4. Bitwise Operators 65](https://image.slidesharecdn.com/81ringring-170217110427/85/The-Ring-programming-language-version-1-2-book-Part-9-of-84-6-320.jpg)
![Ring Documentation, Release 1.2
Operator
. [] () {}
- ~ :Literal [list items]
++ - -
Start:End
* / %
+ -
<< >>
&
| ^
< > <= >=
= !=
not
and or
Assignment = += -= *= /= %=>>= <<= &= ^= |=
Example:
See 3+5*4 # prints 23
14.7. Operators Precedence 66](https://image.slidesharecdn.com/81ringring-170217110427/85/The-Ring-programming-language-version-1-2-book-Part-9-of-84-7-320.jpg)
![Ring Documentation, Release 1.2
for identifier=expression to expression [step expression]
Block of statements
next
Example:
# print numbers from 1 to 10
for x = 1 to 10 see x + nl next
Example:
# Dynamic loop
See "Start : " give nStart
See "End : " give nEnd
See "Step : " give nStep
For x = nStart to nEnd Step nStep
see x + nl
Next
Example:
# print even numbers from 0 to 10
for x = 0 to 10 step 2
see x + nl
next
Example:
# print even numbers from 10 to 0
for x = 10 to 0 step -2
see x + nl
next
• For in Loop
Syntax:
for identifier in List/String [step expression]
Block of statements
next
Example:
aList = 1:10 # create list contains numbers from 1 to 10
for x in aList see x + nl next # print numbers from 1 to 10
15.3 Using The Step option with For in
We can use the Step option with For in to skip number of items in each iteration
Example:
aList = 1:10 # create list contains numbers from 1 to 10
# print odd items inside the list
for x in aList step 2
see x + nl
next
15.3. Using The Step option with For in 69](https://image.slidesharecdn.com/81ringring-170217110427/85/The-Ring-programming-language-version-1-2-book-Part-9-of-84-10-320.jpg)
The Ring programming language version 1.2 book - Part 9 of 84
- 1. Ring Documentation, Release 1.2 12.4 Using Sublime Text 2 Folder : ring/editor/sublime text 2 In the folder Sublime_Text_2 you will find the next three files 1 - ring.json-tmlanguage 2 - ring.sublime-build 3 - ring.tmlanguage Just Copy the files to the next path “C:Users{UserName}AppDataRoamingSublime Text 2PackagesUser” The file ring.sublime-build includes the next line “cmd”: [”B:ringbinring.exe”,”$file”], You can modify it according to the ring.exe path in your machine 12.4. Using Sublime Text 2 60
- 2. Ring Documentation, Release 1.2 12.5 Using Visual Studio IDE Folder : ring/editor/visualstudio Check the ReadMe file for installation instructions. 12.5. Using Visual Studio IDE 61
- 3. CHAPTER THIRTEEN VARIABLES To create a new variable, you just need to determine the variable name & value. The value will determine the variable type and you can change the value to switch between the types using the same variable name. Syntax: <Variable Name> = <Value> Tip: The operator ‘=’ is used here as an Assignment operator and the same operator can be used in conditions, but for testing equality of expressions. Note: The Variable will contains the real value (not a reference). This means that once you change the variable value, the old value will be removed from memory (even if the variable contains a list or object). 13.1 Dynamic Typing Ring is a dynamic programming language that uses Dynamic Typing. x = "Hello" # x is a string see x + nl x = 5 # x is a number (int) see x + nl x = 1.2 # x is a number (double) see x + nl x = [1,2,3,4] # x is a list see x # print list items x = date() # x is a string contains date see x + nl x = time() # x is a string contains time see x + nl x = true # x is a number (logical value = 1) see x + nl x = false # x is a number (logical value = 0) see x + nl 13.2 Deep Copy We can use the assignment operator ‘=’ to copy variables. We can do that to copy values like strings & numbers. Also, we can copy complete lists & objects. The assignment operator will do a complete duplication for us. This operation called Deep Copy 62
- 4. Ring Documentation, Release 1.2 list = [1,2,3,"four","five"] list2 = list list = [] See list # print the first list - no items to print See "********" + nl See list2 # print the second list - contains 5 items 13.3 Weakly Typed Ring is a weakly typed language, this means that the language can automatically convert between data types (like string & numbers) when that conversion make sense. Rules: <NUMBER> + <STRING> --> <NUMBER> <STRING> + <NUMBER> --> <STRING> Note: The same operator ‘+’ can be used as an arithmetic operator or for string concatenation. Example: x = 10 # x is a number y = "20" # y is a string sum = x + y # sum is a number (y will be converted to a number) Msg = "Sum = " + sum # Msg is a string (sum will be converted to a string) see Msg + nl 13.3. Weakly Typed 63
- 5. CHAPTER FOURTEEN OPERATORS In this chapter we will introduce the operators provided by the Ring programming langauge. 14.1 Arithmetic Operators The next table presents all of the arithmetic operators provided by the Ring language. Assume variable X=50 and variable Y=10 then: Operator Description Example Result + Add x+y 60 - Subtract x-y 40 * Multiplies x*y 500 / Divide x/y 5 % Modulus x%y 0 ++ Increment x++ 51 - - Decrement x- - 49 14.2 Relational Operators The next table presents all of the relational operators provided by the Ring language. Assume variable X=50 and variable Y=10 then: Operator Description Example Result = Equal x = y False != Not Equal x != y True > Greater than x > y True < Less than x < y False >= Greater or Equal x >= y True <= Less than or Equal x <= y False 14.3 Logical Operators The next table presents all of the logical operators provided by the Ring language. Assume variable X=True and variable Y=False then: Operator Description Example Result and Logical AND x and y False or Logical OR x or y True not Logical Not not x False 64
- 6. Ring Documentation, Release 1.2 14.4 Bitwise Operators The next table presents all of the bitwise operators provided by the Ring language. Assume variable X=8 and variable Y=2 then: Operator Description Example Result & Binary AND x & y 0 | Binary OR x | y 10 ^ Binary XOR x ^ y 10 ~ Binary Ones Complement ~x -9 << Binary Left Shift x << y 32 >> Binary Right Shift x >> y 2 14.5 Assignment Operators The next table presents all of the assignment operators provided by the Ring language. Assume variable X=8 then: Operator Description Example Result = Assignment x = 10 x=10 += Add AND assignment x += 5 x=13 -= Subtract AND assignment x -= 3 x=5 *= Multiply AND assignment x *= 2 x=16 /= Divide AND assignment x /= 3 x=2.67 %= Modulus AND assignment x %= 2 x=0 <<= Left shift AND assignment x <<= 2 x=32 >>= Right shift AND assignment x >>= 2 x=2 &= Bitwise AND assignment x &= 4 x=0 |= Bitwise OR and assignment x |= 3 x=11 ^= Bitwise XOR and assignment x ^= 4 x=12 14.6 Misc Operators Operator Description :literal using : before identifier mean literal Start:End create list contains items from start to end [list items] define list items list[index] access list item obj.name using the dot operator to access object members (attributes/methods). obj {stmts} execute statements with direct access to object attributes & methods func(para,...) call function using parameters separated by comma 14.7 Operators Precedence The next table present operators from higher precedence (Evaluated first) to lower precedence. 14.4. Bitwise Operators 65
- 7. Ring Documentation, Release 1.2 Operator . [] () {} - ~ :Literal [list items] ++ - - Start:End * / % + - << >> & | ^ < > <= >= = != not and or Assignment = += -= *= /= %=>>= <<= &= ^= |= Example: See 3+5*4 # prints 23 14.7. Operators Precedence 66
- 8. CHAPTER FIFTEEN CONTROL STRUCTURES - FIRST STYLE In this chapter we are going to learn about the control structures provided by the Ring programming language. 15.1 Branching • If Statement Syntax: if Expression Block of statements but Expression Block of statements else Block of statements ok Example: see " Main Menu --------- (1) Say Hello (2) About (3) Exit " give nOption if nOption = 1 see "Enter your name : " give name see "Hello " + name + nl but nOption = 2 see "Sample : using if statement" + nl but nOption = 3 bye else see "bad option..." + nl ok • Switch Statement Syntax: switch Expression on Expression Block of statements other Block of statements off 67
- 9. Ring Documentation, Release 1.2 Example: See " Main Menu --------- (1) Say Hello (2) About (3) Exit " Give nOption Switch nOption On 1 See "Enter your name : " Give name See "Hello " + name + nl On 2 See "Sample : using switch statement" + nl On 3 Bye Other See "bad option..." + nl Off 15.2 Looping • While Loop Syntax: while Expression Block of statements end Example: While True See " Main Menu --------- (1) Say Hello (2) About (3) Exit " Give nOption Switch nOption On 1 See "Enter your name : " Give name See "Hello " + name + nl On 2 See "Sample : using while loop" + nl On 3 Bye Other See "bad option..." + nl Off End • For Loop Syntax: 15.2. Looping 68
- 10. Ring Documentation, Release 1.2 for identifier=expression to expression [step expression] Block of statements next Example: # print numbers from 1 to 10 for x = 1 to 10 see x + nl next Example: # Dynamic loop See "Start : " give nStart See "End : " give nEnd See "Step : " give nStep For x = nStart to nEnd Step nStep see x + nl Next Example: # print even numbers from 0 to 10 for x = 0 to 10 step 2 see x + nl next Example: # print even numbers from 10 to 0 for x = 10 to 0 step -2 see x + nl next • For in Loop Syntax: for identifier in List/String [step expression] Block of statements next Example: aList = 1:10 # create list contains numbers from 1 to 10 for x in aList see x + nl next # print numbers from 1 to 10 15.3 Using The Step option with For in We can use the Step option with For in to skip number of items in each iteration Example: aList = 1:10 # create list contains numbers from 1 to 10 # print odd items inside the list for x in aList step 2 see x + nl next 15.3. Using The Step option with For in 69