{"id":15481801,"url":"https://github.com/rachbowyer/henderson","last_synced_at":"2025-03-28T14:32:16.609Z","repository":{"id":62434345,"uuid":"343831079","full_name":"rachbowyer/henderson","owner":"rachbowyer","description":"SICP's Henderson Picture Language in Clojure","archived":false,"fork":false,"pushed_at":"2021-03-19T12:09:31.000Z","size":811,"stargazers_count":1,"open_issues_count":0,"forks_count":0,"subscribers_count":2,"default_branch":"main","last_synced_at":"2024-10-19T05:18:20.782Z","etag":null,"topics":["clojure","henderson-picture-language","sicp"],"latest_commit_sha":null,"homepage":"https://bowyer.info/sicp-henderson-picture-language","language":"Clojure","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":"other","status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/rachbowyer.png","metadata":{"files":{"readme":"README.md","changelog":null,"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":"2021-03-02T16:02:04.000Z","updated_at":"2021-04-22T11:41:26.000Z","dependencies_parsed_at":"2022-11-01T21:15:48.505Z","dependency_job_id":null,"html_url":"https://github.com/rachbowyer/henderson","commit_stats":null,"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/rachbowyer%2Fhenderson","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/rachbowyer%2Fhenderson/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/rachbowyer%2Fhenderson/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/rachbowyer%2Fhenderson/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/rachbowyer","download_url":"https://codeload.github.com/rachbowyer/henderson/tar.gz/refs/heads/main","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":246046184,"owners_count":20714919,"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":["clojure","henderson-picture-language","sicp"],"created_at":"2024-10-02T05:06:16.872Z","updated_at":"2025-03-28T14:32:16.586Z","avatar_url":"https://github.com/rachbowyer.png","language":"Clojure","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Henderson\n\n\u003cimg src=\"https://github.com/rachbowyer/henderson/blob/main/barton-square-cut.png\" alt=\"Picture of William Barton Rogers transformed by the Square Limit transformation\" width=\"250\"/\u003e\n\nHenderson is a partial implementation in Clojure of the Henderson Picture Language\n(HPL) described in Structure and Interpretation of Computer Programs by Harold Abelson \nand Gerald Sussman (aka [SICP](https://mitpress.mit.edu/sites/default/files/sicp/index.html)).\n\nHPL was invented by Professor Peter Henderson and first \ndescribed in his 1982 paper (Henderson, P. (1982) Functional Geometry. Proc. \nACM Symp. on Lisp and Functional Programming. pp. 179-187). An updated version of\nthe paper is available [here](https://eprints.soton.ac.uk/257577/1/funcgeo2.pdf).\nSICP uses HPL to illustrate abstraction, \nhigh order functions, combinators and composition.\n\nAround 6 years ago, I was working through SICP in Clojure and arrive at Chapter\n2.2.4. I was unable to render my _painters_ so set about writing an\nimplementation in Clojure. I always planned to pull the code out into a standalone\nlibrary, but never found the time until now!\n\n\n## Installation\n\nHenderson is available from Clojars.\n\n[![Clojars Project](https://img.shields.io/clojars/v/rachbowyer/henderson.svg)](https://clojars.org/rachbowyer/henderson)\n\n## Usage\nTo make the Henderson functions available type:\n\n    (require '[henderson.core :as hc])\n    (require '[henderson.examples :as he])\n\nThere are predefined painters _wave_, _wave2_, _wave4_ and _rogers_ as described\nin SICP. The function _show-picture_ will render a painter. \nExamples (from page 133 SICP 2nd Edition)\n\n     (hc/show-picture (hc/right-split he/wave 4) 400 400)\n     (hc/show-picture (hc/corner-split he/rogers 4) 400 400)\n\nNote that the origin is at the top left, positive x goes right\nand positive y goes down in accordance with Java2d and most UI systems.\n\nFor more information see the docs in /doc and of course SICP!\n\n## License for Henderson\n\nDistributed under the Creative Commons Attribution-ShareAlike 4.0\nInternational licence ([\"CC BY-SA 4.0\"](https://creativecommons.org/licenses/by-sa/4.0/))\n\n\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Frachbowyer%2Fhenderson","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Frachbowyer%2Fhenderson","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Frachbowyer%2Fhenderson/lists"}