Action!

1 program Added 2026-02-08T13:46:46Z Agent: claude-codeModel: opusWebSearch: disabled Evidence Report issue View issues
Aliases: Action
Provenance: commit fc3e1de505 · authored 2026-02-08T14:48:54+01:00 · agent claude-code · model opus

Sources mentioning this language

5 sources · pl_id: pl/action
LLM (this repo) · 1PldbWikipediaRosettacodeWikidata · Q343587

Wikipedia infobox ↗

Pulled from the wikimedia/structured-wikipedia snapshot — see data/raw/wikipedia_pl_facts.*.jsonl and pl_fact.csv for the long-table provenance.

Designed byOptimized Systems Software
First appeared1983

Related languages

Acton (0.38)Active Oberon (0.30)ActionScript (0.27)Potion (0.27)ACS (0.26)

Real programs from Software Heritage

No SWH evidence indexed yet for this language. (Either the SWH mining hasn't reached this language's extensions, or no matching files exist in the archive.)

Programs collected by LLM agents experimental · unverified

Gathered by LLM agents during the experiment that started this catalogue. They are not verified: the agent names an origin, but a program can be altered or invented — an audit found one attributed to a file that does not exist, in a syntax the language does not have. Prefer the programs archived by Software Heritage above. The catalogue's goal is the languages themselves, grounded in sources (PLDB, Wikipedia, Rosetta Code, …), with real archived programs; these examples may be dropped.

Fibonacci Sequence

Provenance: commit fc3e1de505 · authored 2026-02-08T14:48:54+01:00 · agent claude-code · model opus · WebSearch disabled
code.act · license: GNU Free Documentation License · added: 2026-02-08T13:46:46Z
PROC Fibonacci(INT n)
  INT a, b, temp, i

  a = 0
  b = 1

  PrintF("Fibonacci sequence up to %I terms:%E", n)
  FOR i = 1 TO n
  DO
    PrintI(a)
    Put(32)
    temp = a + b
    a = b
    b = temp
  OD
  PutE()
RETURN

PROC Main()
  Fibonacci(20)
RETURN

Contribute — propose a file extension

Tell us where to find evidence about Action! (mapped to pl/action). A reference URL is required; at least one of extension or program code must be provided too. A maintainer reviews each submission via a draft PR before anything lands.
Optional: attach a program from that URL
If the reference URL points at a single source file you'd like to add as an example program, paste it below. The workflow will write it under languages/Action!/programs/<sha>/. Keep under ~200 lines.
(or open the pre-filled issue directly)
← Action symbol ActionLang →