Straw

String manipulation esolang

Usage

straw.rb <file> [-u]

The -u flag is to directly read the file in UTF-8, without CP437 decoding it.

Reference

Straw have 3 stacks:

• Two main stacks (the first is initialized with an empty string and the second with Hello, World!)
• One temporary stack

Straw use a modified CP437 encoding (FF is …).

Commands

Command	Description
(	String literal, ends on ). Parenthesis are nestable, and ` is the escape character.
+	Pop b, pop a and push a and b concatened.
*	Pop b, pop a and push length of b times a.
&	Pop a string and evaluate it.
:	Duplicate the top of the stack.
;	Drop the top of the stack.
,	Swap the two items on the top of the stack.
~	Toggle the current stack.
-	Pop an item from the inactive stack and push it on the active one.
>	Pop a string and print it. This don't print a trailing nweline.
<	Read a string from STDIN and push it.
?	Have a 1/2 chance of skipping the next instruction.
'	Pop condition, if and else and execute if if the length of condition is >0, else otheriwse.
=	Pop two items, push Y if the two items are equal, an empty string otherwise.
!	Pop two items, push Y if the two items are not equal, an empty string otherwise.
{	Pop an item and push its first character.
}	Pop an item and push it without the first character.
"	Pop a string and reverse it.
/	Pop replacement, regex and string and push string with all matching occurences of regex replaced by replacement.
.	Pop a regex and a string and push Y if the regex match the string, an empty string otherwise.
]	Pop var and a value, set the variable var to the value.
[	Pop var and a push the variable var.
#	Pop a decimal string, convert it to unary and push it.
$	Pop a string and push it length in decimal.
%	Pop a string, enclose it in parentheses and push it.
@	See the source code for a description.
⌠	Pop a and b, drop length of a characters on b and push b.
⌡	Pop a and b, take length of a characters on b and push b.
`	`
¡	Get the depth of the stack.
≤	Pop a string of length n and push the n-th element of the stack (0 = most deep element).
≥	Pop a string of length n and push the n-th element of the stack (0 = least deep element).
÷	Pop a and b and push b / a (unary arithmetic).
¥	Pop a and b and push b mod a (unary arithmetic).
æ	Pop a character and push its CP437 ordinal.
Æ	Pop a number and push the CP437 character associated.
ñ	Pop an item and push it on the temporary stack.
Ñ	Pop an item on the temporary stack and push it on the main stack.
≈	Swap the current stack and the temporary one.
σ	Clear the temporary stack.
¢	Pop a list of list and a string, and for each element in the list, replace the first element (regex) by the second in the string.
«	Pop a string, sum the CP437 codepoints of each character in the string and push an unary number.
»	Pop a string and push it length encoded in CP437 codepoints.
Ω	Pop a and b and push b joined with a.
£	Pop a string and evaluate it while peeking the top of the stack is not an empty string.
_	Print the stack.

There is also a special command, Ђ, which should'nt be used directly in the code. (Anyway, it can't be in a source file without the Unicode mode.)

Any character that isn't a command is pushed on the current stack.

Examples

• hello_world.str: A hello world
• truth_machine.str: A truth machine
• quine.str: A quine