Set

''This article is about Sept 25th 2016's esolang Set. The older Set language is now called Recurl.''

The Set programming language - Only one command, endless possibilities! Based off the original specification by reddit user qwertyu63. Initial development by Matheus Avellar.

= About Set = Set is an esolang with only one command: "Set". It also supports conditional statements and variable assignments. Output is ASCII-based.

Variables
Set supports 52 assignable variables. Each variable is a single upper or lower case letter and stores a single unbounded integer. All lower case variables are initialized to 0; all upper case variables are initialized to their ASCII representation (65-90). There is also a special system variable indicated by a question mark, which contains the line of code currently being executed.

Commands
As previously estabilished, there is only 1 command in Set:. Each  command must be on its own line, and is case insensitive. takes two arguments, each separated by 1 space :


 * must be either a variable or an exclamation point.
 * must be either a variable, an exclamation point, a combiner or an integer.

On most occasions, the  command will set the variable on argument   to the value of argument.

Example: set k 10 > Assings 10 to the variable 'k' set a A   > Assings ASCII value of 'A' (65) to the variable 'a'

Exclamation point
Exclamation points indicate input/output. When used as argument:


 * : Outputs the ASCII character matching argument  to the screen.
 * : Takes one ASCII character as input and sets argument  to the matching integer.

Example: > When used as argument "A" set ! A set ! B > Outputs: AB > When used as argument "B" set a ! > Prompts the user for a one-character-long value input > and assigns it to the variable 'a' set b ! > Received "B" > 'b' now equals 66

Question mark
Question marks represent the line of code which is being executed. When used as argument:


 * : Works as a 'go to' function. Defines the value of  as the line of code to be executed next
 * : Acts as a regular variable. Assigns argument  the number of the current line of code

Example: set a ? > Defines 'a' as 1 set ? 1 > Jumps to line 1, thus creating an infinite loop set z 1 > This line will never be executed, as the code cannot reach it

Combiners
Combiners allow you to combine two numbers into one. There are two valid combiners; each used in the place of argument :


 * : is equal to  plus.
 * : is equal to  minus.

and  must be either a variable or a single digit integer.

Example: set b (A+1) > Adds 1 to ASCII value of 'A' (65) > b becomes 66 (ASCII for 'B')

Conditionals
By putting a conditional in front of a  command, you can make that command only run in some situations. There are two valid conditionals:


 * :  must not equal.
 * :  must equal.

If the condition is not met, the command is not run. X and Y must be either a variable or a single digit integer.

Example: set a 1 [a=0] set a 2 > If 'a' equals 0, then set 'a' to 2 [a/0] set a 3 > If 'a' is not equal to 0, then set 'a' to 3 > 'a' is 3

Comments
Although not specified in the original concept of the Set language, the  (greater than) character may be used to insert comments on the Set code.

Example: > Whole line comment. Starts with a '>' symbol. This line is completely ignored by the parser. set a 10 > Inline comment. Starts after a 'set' command, which runs normally. set b 20 > By convention, inline comments should always be separated of           > the 'set' command by at least 2 spaces

= Example code =

Hello world!
Here is a 97 bytes example of a "Hello world!" program on Set: set ! H set ! E set ! L set ! L set ! O set ! 32 set ! W set ! O set ! R set ! L set ! D set ! 33 Outputs: HELLO WORLD!

99 Bottles of Beer
A 932 bytes "99 Bottles of Beer" program on Set: set l 10 set s 32 set m 44 set t 48 set a 57 set b 57 set e (a-c) set f (b-d) [i=4] set i 0 set ! e set ! f set ! s set ! B set ! O set ! T set ! T set ! L set ! E set ! S set ! s set ! O set ! F set ! s set ! B set ! E set ! E set ! R [i=1] set ? 49 set ! s set ! O set ! N set ! s set ! T set ! H set ! E set ! s set ! W set ! A set ! L set ! L set ! l [k=1] set ? 97 [i=3] set i 4 [i=4] set ! l [i=4] set ? 9 [i/2] set i 1 [i=1] set ? 9 [i=2] set ? 87 set ! l set ! T set ! A set ! K set ! E set ! s set ! O set ! N set ! E set ! s set ! D set ! O set ! W set ! N set ! m set ! s set ! P set ! A set ! S set ! S set ! s set ! I set ! T set ! s set ! A set ! R set ! O set ! U set ! N set ! D set ! l set i 2 [d=9] set d l [d/l] set d (d+1) [d=l] set c (c+1) [d=l] set d 0 set e (a-c) set f (b-d) [e=f] set ? 93 [c=l] set ? 91 [i=2] set i 3 [i=3] set ? 9 [d=l] set ? 93 [d/l] set ? 88 [e=t] set ? 95 set ? 88 set k 1 set ? 9 > EOF Outputs: 99 BOTTLES OF BEER ON THE WALL 99 BOTTLES OF BEER TAKE ONE DOWN, PASS IT AROUND 98 BOTTLES OF BEER ON THE WALL ... 01 BOTTLES OF BEER ON THE WALL 01 BOTTLES OF BEER TAKE ONE DOWN, PASS IT AROUND 00 BOTTLES OF BEER ON THE WALL

= Links =

Interpreter