Quackery

Quackery is an open source, lightweight, entry level concatenative language for educational and recreational programming.

It is coded as a Python 3 function in around 48k of Pythonscript, about half of which is a string of Quackery code.

The Quackery GitHub repository, which includes the Quackery manual The Book of Quackery in pdf form, is at https://github.com/GordonCharlton/Quackery.

Examples of Quackery code

More examples can be found at http://rosettacode.org/wiki/Category:Quackery.

Naive Recursive Fibonacci

  [ dup  2 < if done
    dup  1 - recurse
    swap 2 - recurse + ]        is fibonacci    (       n --> n       )

Insertion Sort

  [ stack ]                     is sort.test    (         --> s       )


  [ ]'[ sort.test put
    [] swap witheach
      [ swap 2dup findwith
        [ over sort.test share
          do ] [ ]
        nip stuff ]
    sort.test release ]         is sortwith     (       [ --> [       )

  [ sortwith > ]                is sort         (       [ --> [       )

• sort.test is an ancillary stack. There are no variables in Quackery, ancillary stacks include serving as local variables amongst their uses.

• ]'[ is called "meta-quote" - it grants the behaviour of ' ("quote") to sortwith as syntactic sugar. Without the meta-quote in sortwith, sort would be defined as [ ' > sortwith ] is sort

A Quackery Quine

[ this unbuild $ " is quine" join quackery ]

This nest creates a Quackery word called quine that creates a copy of itself.

• this -- put a copy of the nest it is in (a nest is items bounded by [ and ]) on the stack.
• unbuild -- decompile the item on the top of stack.
• $ " is quine" -- put the string literal " is quine" on the top of stack.
• join -- concatenate top two items.
• quackery -- compile and evaluate ToS. (quackery is defined as [ build do ] is quackery)