{"id":16315602,"url":"https://github.com/andreasabel/sit","last_synced_at":"2025-07-19T14:32:19.603Z","repository":{"id":59150876,"uuid":"91352271","full_name":"andreasabel/Sit","owner":"andreasabel","description":"Prototypical type checker for Type Theory with Sized Natural Numbers","archived":false,"fork":false,"pushed_at":"2024-09-22T19:40:59.000Z","size":72,"stargazers_count":6,"open_issues_count":0,"forks_count":0,"subscribers_count":3,"default_branch":"master","last_synced_at":"2025-03-18T14:53:39.350Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"Haskell","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"mit","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/andreasabel.png","metadata":{"files":{"readme":"README.md","changelog":"CHANGELOG.md","contributing":null,"funding":null,"license":"LICENSE","code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2017-05-15T15:14:57.000Z","updated_at":"2024-09-22T19:41:02.000Z","dependencies_parsed_at":"2024-04-06T06:24:33.703Z","dependency_job_id":"84989b26-2c91-4c9e-b7aa-5b8f69d64270","html_url":"https://github.com/andreasabel/Sit","commit_stats":{"total_commits":18,"total_committers":2,"mean_commits":9.0,"dds":0.05555555555555558,"last_synced_commit":"53637d795060a88ff26e862cdc1d56b30041552b"},"previous_names":[],"tags_count":5,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/andreasabel%2FSit","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/andreasabel%2FSit/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/andreasabel%2FSit/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/andreasabel%2FSit/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/andreasabel","download_url":"https://codeload.github.com/andreasabel/Sit/tar.gz/refs/heads/master","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":245022468,"owners_count":20548544,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-10-10T21:57:58.492Z","updated_at":"2025-03-22T21:31:26.057Z","avatar_url":"https://github.com/andreasabel.png","language":"Haskell","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Sit: size-irrelevant types\nA prototype dependently-typed language with sized natural numbers\n\nSit parses and typechecks `.agda` that conform to the Sit language syntax.\n\nSyntax (excerpt):\n```agda\n--- Lexical stuff\n\n--- Single line comment\n{- Block comment -}\n--;               --- End of declaration (mandatory)\nf_x'1             --- identifiers start with a letter, then have letters, digits, _ and '\n\n--- Declarations\n\nx : T --;         --- type signature\nx = t --;         --- definition\nopen import M --; --- ignored, for Agda compatibility\n\n--- Sit specifics\n\noo                --- infinity size\ni + 1             --- successor size\n\nNat a             --- type of natural numbers below size a\nzero a            --- number zero (a is size annotation)\nsuc a n           --- successor of n (a is size annotation)\n\nforall .i  -\u003e T   --- irrelevant size quantification\nforall ..i -\u003e T   --- relevant size quantification\n\nfix T t n         --- recursive function over natural numbers\n                  ---   T: return type\n                  ---   t: functional\n                  ---   n: natural number argument\n\n\\{ (zero _) -\u003e t; (suc _ x) -\u003e u }   --- case distinction function\n\n--- Inherited Agda syntax\n\nU -\u003e T            --- non-dependent function type\n(x y z : U) -\u003e T  --- dependent function type\n\\ x y z -\u003e t      --- lambda-abstraction\nt u               --- application\n\nSet               --- first universe\nSet1              --- second universe\nSet a             --- universe of level a\n\n```\n\n## Limitations\n\nSit only understands a tiny subset of the Agda language.\nSit does not understand layout, instead each declaration has to be terminated with\ncomment `--;`.\n\n## Installation\n\nRequires GHC and cabal, for instance via the Haskell Platform.\nIn a shell, type\n```\n  cabal install\n```\n\n## Test\n\nIn a shell, type\n```\n  Sit.bin test/Test.agda\n```\n\n## Example\n\nThis is the addition function in Sit:\n```\n--- Addition of natural numbers\n\nplus : forall .i -\u003e Nat i -\u003e Nat oo -\u003e Nat oo   --;\nplus = \\ i x y -\u003e\n  fix (\\ i x -\u003e Nat oo)\n      (\\ _ f -\u003e \\\n        { (zero _)  -\u003e y\n        ; (suc _ x) -\u003e suc oo (f x)\n        })\n      x\n```\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fandreasabel%2Fsit","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fandreasabel%2Fsit","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fandreasabel%2Fsit/lists"}