slang

…is a experimental Forth-like stack language implemented in D.

Example

1 i $

§ incr dup @ 1 + swp $ ;
§ withinBounds @ 100 < ;

§ fizz? @ 3 % 0 = ;
§ buzz? @ 5 % 0 = ;

§ fizzbuzz_or_fizz     buzz? if fizzbuzz then fizz else . pop ;
§ buzz_or_print    dup buzz? if pop buzz then @    else . pop ;

§ branch dup fizz? if fizzbuzz_or_fizz then buzz_or_print else ;

§ loop i withinBounds if i branch i incr loop then else ;

loop

This listing implements the common FizzBuzz example in slang. It may be executed by compiling the REPL using dub build in the project directory and running ./slang example/fizzbuzz.slang.

Words

Currently implemented primitives:

Word	Description
`§`	Custom word definition
`$`, `@`	Single token variable binding, resolution
`if`, `then`, `else`	Conditional primitives
`+`, `*`, `/`, `%`	Common artithmetics
`.`	Non destructive printing of top-of-stack
`pop`	Remove uppermost stack element
`dup`	Duplicate top-of-stack
`swp`	Swap the first two stack elements
`ovr`	Place a copy of the second stack element on top-of-stack
`rot`	Rotate the top three stack elements
`true`	Write true boolean value to top-of-stack
`false`	Write false boolean value to top-of-stack
`not`	Negate boolean value
`and`	Boolean and
`or`	Boolean or
`<`	Compare size of two integers
`=`	Compare equality of two stack values
`#`	Debug word printing the whole stack to stdout

Further words are implemented in library/base.slang.