{"id":13709439,"url":"https://github.com/purescript/purescript-exists","last_synced_at":"2026-03-07T11:02:08.937Z","repository":{"id":16958688,"uuid":"19721006","full_name":"purescript/purescript-exists","owner":"purescript","description":"Existential types as a library","archived":false,"fork":false,"pushed_at":"2022-11-16T15:42:55.000Z","size":38,"stargazers_count":34,"open_issues_count":4,"forks_count":8,"subscribers_count":1,"default_branch":"master","last_synced_at":"2026-01-15T05:43:28.172Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":"","language":"PureScript","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"bsd-3-clause","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/purescript.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}},"created_at":"2014-05-13T01:01:16.000Z","updated_at":"2024-06-06T15:31:24.000Z","dependencies_parsed_at":"2022-09-25T07:14:16.497Z","dependency_job_id":null,"html_url":"https://github.com/purescript/purescript-exists","commit_stats":null,"previous_names":["paf31/purescript-exists"],"tags_count":12,"template":false,"template_full_name":null,"purl":"pkg:github/purescript/purescript-exists","repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/purescript%2Fpurescript-exists","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/purescript%2Fpurescript-exists/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/purescript%2Fpurescript-exists/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/purescript%2Fpurescript-exists/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/purescript","download_url":"https://codeload.github.com/purescript/purescript-exists/tar.gz/refs/heads/master","sbom_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/purescript%2Fpurescript-exists/sbom","scorecard":{"id":749961,"data":{"date":"2025-08-11","repo":{"name":"github.com/purescript/purescript-exists","commit":"f765b4ace7869c27b9c05949e18c843881f9173b"},"scorecard":{"version":"v5.2.1-40-gf6ed084d","commit":"f6ed084d17c9236477efd66e5b258b9d4cc7b389"},"score":3.8,"checks":[{"name":"Code-Review","score":4,"reason":"Found 9/22 approved changesets -- score normalized to 4","details":null,"documentation":{"short":"Determines if the project requires human code review before pull requests (aka merge requests) are merged.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#code-review"}},{"name":"Packaging","score":-1,"reason":"packaging workflow not detected","details":["Warn: no GitHub/GitLab publishing workflow detected."],"documentation":{"short":"Determines if the project is published as a package that others can easily download, install, easily update, and uninstall.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#packaging"}},{"name":"Dangerous-Workflow","score":10,"reason":"no dangerous workflow patterns detected","details":null,"documentation":{"short":"Determines if the project's GitHub Action workflows avoid dangerous patterns.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#dangerous-workflow"}},{"name":"Maintained","score":0,"reason":"0 commit(s) and 0 issue activity found in the last 90 days -- score normalized to 0","details":null,"documentation":{"short":"Determines if the project is \"actively maintained\".","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#maintained"}},{"name":"Binary-Artifacts","score":10,"reason":"no binaries found in the repo","details":null,"documentation":{"short":"Determines if the project has generated executable (binary) artifacts in the source repository.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#binary-artifacts"}},{"name":"Pinned-Dependencies","score":0,"reason":"dependency not pinned by hash detected -- score normalized to 0","details":["Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/ci.yml:13: update your workflow using https://app.stepsecurity.io/secureworkflow/purescript/purescript-exists/ci.yml/master?enable=pin","Warn: third-party GitHubAction not pinned by hash: .github/workflows/ci.yml:15: update your workflow using https://app.stepsecurity.io/secureworkflow/purescript/purescript-exists/ci.yml/master?enable=pin","Warn: GitHub-owned GitHubAction not pinned by hash: .github/workflows/ci.yml:19: update your workflow using https://app.stepsecurity.io/secureworkflow/purescript/purescript-exists/ci.yml/master?enable=pin","Warn: npmCommand not pinned by hash: .github/workflows/ci.yml:25","Warn: npmCommand not pinned by hash: .github/workflows/ci.yml:26","Info:   0 out of   2 GitHub-owned GitHubAction dependencies pinned","Info:   0 out of   1 third-party GitHubAction dependencies pinned","Info:   0 out of   2 npmCommand dependencies pinned"],"documentation":{"short":"Determines if the project has declared and pinned the dependencies of its build process.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#pinned-dependencies"}},{"name":"Token-Permissions","score":0,"reason":"detected GitHub workflow tokens with excessive permissions","details":["Warn: no topLevel permission defined: .github/workflows/ci.yml:1","Info: no jobLevel write permissions found"],"documentation":{"short":"Determines if the project's workflows follow the principle of least privilege.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#token-permissions"}},{"name":"CII-Best-Practices","score":0,"reason":"no effort to earn an OpenSSF best practices badge detected","details":null,"documentation":{"short":"Determines if the project has an OpenSSF (formerly CII) Best Practices Badge.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#cii-best-practices"}},{"name":"Security-Policy","score":0,"reason":"security policy file not detected","details":["Warn: no security policy file detected","Warn: no security file to analyze","Warn: no security file to analyze","Warn: no security file to analyze"],"documentation":{"short":"Determines if the project has published a security policy.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#security-policy"}},{"name":"Vulnerabilities","score":10,"reason":"0 existing vulnerabilities detected","details":null,"documentation":{"short":"Determines if the project has open, known unfixed vulnerabilities.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#vulnerabilities"}},{"name":"Fuzzing","score":0,"reason":"project is not fuzzed","details":["Warn: no fuzzer integrations found"],"documentation":{"short":"Determines if the project uses fuzzing.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#fuzzing"}},{"name":"License","score":10,"reason":"license file detected","details":["Info: project has a license file: LICENSE:0","Info: FSF or OSI recognized license: BSD 3-Clause \"New\" or \"Revised\" License: LICENSE:0"],"documentation":{"short":"Determines if the project has defined a license.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#license"}},{"name":"Signed-Releases","score":-1,"reason":"no releases found","details":null,"documentation":{"short":"Determines if the project cryptographically signs release artifacts.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#signed-releases"}},{"name":"Branch-Protection","score":0,"reason":"branch protection not enabled on development/release branches","details":["Warn: branch protection not enabled for branch 'master'"],"documentation":{"short":"Determines if the default and release branches are protected with GitHub's branch protection settings.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#branch-protection"}},{"name":"SAST","score":0,"reason":"SAST tool is not run on all commits -- score normalized to 0","details":["Warn: 0 commits out of 23 are checked with a SAST tool"],"documentation":{"short":"Determines if the project uses static code analysis.","url":"https://github.com/ossf/scorecard/blob/f6ed084d17c9236477efd66e5b258b9d4cc7b389/docs/checks.md#sast"}}]},"last_synced_at":"2025-08-22T20:00:57.787Z","repository_id":16958688,"created_at":"2025-08-22T20:00:57.787Z","updated_at":"2025-08-22T20:00:57.787Z"},"host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":286080680,"owners_count":30212103,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2026-03-07T09:02:10.694Z","status":"ssl_error","status_checked_at":"2026-03-07T09:02:08.429Z","response_time":53,"last_error":"SSL_read: unexpected eof while reading","robots_txt_status":"success","robots_txt_updated_at":"2025-07-24T06:49:26.215Z","robots_txt_url":"https://github.com/robots.txt","online":false,"can_crawl_api":true,"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":"2024-08-02T23:00:39.213Z","updated_at":"2026-03-07T11:02:08.920Z","avatar_url":"https://github.com/purescript.png","language":"PureScript","readme":"# purescript-exists\n\n[![Latest release](http://img.shields.io/github/release/purescript/purescript-exists.svg)](https://github.com/purescript/purescript-exists/releases)\n[![Build status](https://github.com/purescript/purescript-exists/workflows/CI/badge.svg?branch=master)](https://github.com/purescript/purescript-exists/actions?query=workflow%3ACI+branch%3Amaster)\n[![Pursuit](https://pursuit.purescript.org/packages/purescript-exists/badge)](https://pursuit.purescript.org/packages/purescript-exists)\n\nThe `Exists` type, for encoding existential types.\n\n## Installation\n\n```\nspago install exists\n```\n\n## Overview\n\nThe type `Exists f` is isomorphic to the existential type `exists a. f a`.\n\nFor example, consider the type `exists s. Tuple s (s -\u003e Tuple s a)` which represents infinite streams of elements of type `a`.\n\nThis type can be constructed by creating a type constructor `StreamF` as follows:\n\n```purescript\ndata StreamF a s = StreamF s (s -\u003e Tuple s a)\n```\n\nWe can then define the type of streams using `Exists`:\n\n```purescript\ntype Stream a = Exists (StreamF a)\n```\n\nThe `mkExists` and `runExists` functions then enable packing and unpacking of `SteamF` into/out of `Stream`.\n\n## Documentation\n\nModule documentation is [published on Pursuit](http://pursuit.purescript.org/packages/purescript-exists).\n","funding_links":[],"categories":["Essential libraries"],"sub_categories":[],"project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fpurescript%2Fpurescript-exists","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fpurescript%2Fpurescript-exists","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fpurescript%2Fpurescript-exists/lists"}