{"path":"/sutl/core-library/part-3","content":{"title":"sUTL core library, part 3","summary":"Named reusable transforms, with full declarations and explicit dependency lists.","body":"[sUTL](/sutl) · [Guide](/sutl/guide) · [Reference](/sutl/reference) · [Examples](/sutl/examples)\n\nThese are declarations from the core distribution. Compile their named requirements against the complete distribution; an isolated declaration may depend on others. Historical `language: \"sUTL0\"` labels are retained as archived input, accepted by the current language. See [declarations and libraries](/sutl/guide/declarations-and-libraries).\n\n## when_core_emlynoregan_com\n\n```json\n{\n \"name\": \"when_core_emlynoregan_com\",\n \"transform-t\": [\n \"^%\",\n {\n \"&\": \"reduce\",\n \"list\": \"^@.cases\",\n \"accum\": {\n \"found\": false,\n \"result\": null\n },\n \"t\": {\n \"'\": {\n \"&\": \"if\",\n \"cond\": {\n \"'\": \"^@.accum.found\"\n },\n \"true\": {\n \"'\": \"^@.accum\"\n },\n \"false\": {\n \"'\": {\n \"&\": \"if\",\n \"cond\": {\n \"'\": [\n \"&&&\",\n [\n \"&=\",\n {\n \"&\": \"type\",\n \"value\": \"^@.item\"\n },\n \"list\"\n ],\n [\n \"&=\",\n {\n \"&\": \"len\",\n \"list\": \"^@.item\"\n },\n 2\n ]\n ]\n },\n \"true\": {\n \"'\": {\n \"&\": \"if\",\n \"cond\": {\n \"'\": {\n \"!\": {\n \"!\": \"^@.item.0\"\n }\n }\n },\n \"true\": {\n \"'\": {\n \"found\": true,\n \"result\": {\n \"!\": \"^@.item.1\"\n }\n }\n },\n \"false\": {\n \"'\": \"^@.accum\"\n }\n }\n },\n \"false\": {\n \"'\": {\n \"found\": true,\n \"result\": {\n \"!\": \"^@.item\"\n }\n }\n }\n }\n }\n }\n }\n },\n \"result\"\n ]\n}\n```\n\n## isdict_core_emlynoregan_com\n\n```json\n{\n \"name\": \"isdict_core_emlynoregan_com\",\n \"transform-t\": [\n \"&=\",\n {\n \"&\": \"type\",\n \"value\": \"^@.item\"\n },\n \"map\"\n ]\n}\n```\n\n## islist_core_emlynoregan_com\n\n```json\n{\n \"name\": \"islist_core_emlynoregan_com\",\n \"transform-t\": [\n \"&=\",\n {\n \"&\": \"type\",\n \"value\": \"^@.item\"\n },\n \"list\"\n ]\n}\n```\n\n## issimple_core_emlynoregan_com\n\nRequires: `isdict_core`, `islist_core`.\n\n```json\n{\n \"name\": \"issimple_core_emlynoregan_com\",\n \"transform-t\": [\n \"&!\",\n [\n \"&||\",\n {\n \"&\": \"isdict_core\"\n },\n {\n \"&\": \"islist_core\"\n }\n ]\n ],\n \"requires\": [\n \"isdict_core\",\n \"islist_core\"\n ]\n}\n```\n\n## newdiff_core_emlynoregan_com\n\nRequires: `hasitems`, `isdict`, `islist`, `switch`, `map_core`, `isinlist`, `newdiff_core`.\n\n```json\n{\n \"name\": \"newdiff_core_emlynoregan_com\",\n \"transform-t\": {\n \"!\": {\n \":\": {\n \"!\": {\n \":\": {\n \"&\": \"if\",\n \"cond\": {\n \":\": {\n \"!\": \"^@.keepvalue\"\n }\n },\n \"true\": {\n \":\": \"^@.value\"\n }\n }\n },\n \"value\": {\n \"&\": \"switch\",\n \"value\": {\n \"&\": \"type\",\n \"value\": \"^@.new\"\n },\n \"cases\": [\n [\n \"map\",\n {\n \"&\": \"if\",\n \"cond\": {\n \"'\": {\n \"&\": \"isdict\",\n \"item\": \"^@.old\"\n }\n },\n \"true\": {\n \"'\": {\n \"&\": \"makemap\",\n \"value\": {\n \"&\": \"map_core\",\n \"list\": {\n \"&\": \"keys\",\n \"map\": \"^@.new\"\n },\n \"t\": {\n \":\": {\n \"&\": \"if\",\n \"cond\": {\n \":\": {\n \"&\": \"isinlist\",\n \"list\": {\n \"&\": \"keys\",\n \"map\": \"^@.old\"\n }\n }\n },\n \"true\": {\n \"'\": {\n \"&\": \"if\",\n \"cond\": {\n \":\": [\n \"&=\",\n [\n \"^%\",\n \"^@.new\",\n \"^@.item\"\n ],\n [\n \"^%\",\n \"^@.old\",\n \"^@.item\"\n ]\n ]\n },\n \"true\": null,\n \"false\": {\n \":\": {\n \"!\": {\n \":\": {\n \"&\": \"if\",\n \"cond\": {\n \":\": {\n \"!\": \"^@.keepvalue\"\n }\n },\n \"true\": {\n \":\": [\n \"^@.item\",\n \"^@.value\"\n ]\n }\n }\n },\n \"value\": {\n \"&\": \"newdiff_core\",\n \"old\": [\n \"^%\",\n \"^@.old\",\n \"^@.item\"\n ],\n \"new\": [\n \"^%\",\n \"^@.new\",\n \"^@.item\"\n ]\n }\n }\n }\n }\n },\n \"false\": {\n \":\": [\n \"^@.item\",\n [\n \"^%\",\n \"^@.new\",\n \"^@.item\"\n ]\n ]\n }\n }\n }\n }\n }\n },\n \"false\": {\n \":\": \"^@.new\"\n }\n }\n ],\n [\n \"list\",\n {\n \"!\": {\n \":\": {\n \"&\": \"if\",\n \"cond\": {\n \":\": {\n \"&\": \"hasitems\"\n }\n },\n \"true\": {\n \":\": \"^@.list\"\n },\n \"false\": []\n }\n },\n \"list\": {\n \"&\": \"if\",\n \"cond\": {\n \"'\": {\n \"&\": \"islist\",\n \"item\": \"^@.old\"\n }\n },\n \"true\": {\n \"'\": [\n \"^%\",\n {\n \"&\": \"reduce\",\n \"list\": \"^@.new\",\n \"accum\": {\n \"index\": 0,\n \"result\": []\n },\n \"t\": {\n \":\": {\n \"index\": [\n \"&+\",\n \"^@.accum.index\",\n 1\n ],\n \"result\": [\n \"&&\",\n \"^@.accum.result\",\n [\n {\n \"!\": {\n \":\": {\n \"&\": \"if\",\n \"cond\": {\n \":\": {\n \"!\": \"^@.keepvalue\"\n }\n },\n \"true\": {\n \":\": \"^@.value\"\n }\n }\n },\n \"value\": {\n \"&\": \"newdiff_core\",\n \"old\": [\n \"^%\",\n \"^@.old\",\n \"^@.accum.index\"\n ],\n \"new\": \"^@.item\"\n }\n }\n ]\n ]\n }\n }\n },\n \"result\"\n ]\n },\n \"false\": {\n \":\": \"^@.new\"\n }\n }\n }\n ],\n {\n \"&\": \"if\",\n \"cond\": {\n \":\": [\n \"&=\",\n \"^@.new\",\n \"^@.old\"\n ]\n },\n \"false\": {\n \":\": \"^@.new\"\n }\n }\n ]\n }\n }\n },\n \"keepvalue\": {\n \":\": [\n \"&||\",\n \"^@.value\",\n [\n \"&!\",\n {\n \"&\": \"isinlist\",\n \"item\": {\n \"&\": \"type\"\n },\n \"list\": [\n \"null\",\n \"map\",\n \"list\"\n ]\n }\n ]\n ]\n }\n },\n \"requires\": [\n \"hasitems\",\n \"isdict\",\n \"islist\",\n \"switch\",\n \"map_core\",\n \"isinlist\",\n \"newdiff_core\"\n ]\n}\n```\n\n\n[Core library contents](/sutl/core-library)\n\n## Source\n\nAdapted from [the sUTL source material](https://github.com/emlynoregan/sutl-language/blob/0c3463677495ea00767f8266ae900eb4e2f98617/core-library.json).\n\n[Back to sUTL](/sutl) · [Software & Agents](/topics/software-and-agents) · [All topics](/guide)","author":"Emlyn O'Regan"}}