initial commit

2026-03-04 20:24:33 -08:00
commit bb510fea4a
39 changed files with 14640 additions and 0 deletions
--- a/grammar.js
+++ b/grammar.js
@@ -0,0 +1,149 @@
+/**
+ * @file Newt grammar for tree-sitter
+ * @author Steve Dunham <dunhamsteve@gmail.com>
+ * @license MIT
+ *
+ * I copied some unpublished code that I used years ago for pi-forall
+ */
+
+/// <reference types="tree-sitter-cli/dsl" />
+// @ts-check
+
+const sep = (
+  /** @type {RuleOrLiteral} */ sep,
+  /** @type {RuleOrLiteral} */ rule,
+) => optional(seq(rule, repeat(seq(sep, rule))));
+const sep1 = (
+  /** @type {RuleOrLiteral} */ sep,
+  /** @type {RuleOrLiteral} */ rule,
+) => seq(rule, repeat(seq(sep, rule)));
+const layout = (
+  /** @type {GrammarSymbols<any>} */ $,
+  /** @type {RuleOrLiteral} */ rule,
+) => seq($.start, repeat(seq($.semi, rule)), $.end)
+// choice(
+//   seq("{", optional(sep1(";", rule)), "}"),
+// );
+
+module.exports = grammar({
+  name: "newt",
+  word: ($) => $.identifier,
+  extras: ($) => [$.comment, $._ws],
+  externals: ($) => [$.start, $.semi, $.end, $._ws],
+  rules: {
+    // TODO: add the actual grammar rules
+    source_file: ($) => $.module,
+    comment: ($) =>
+      token(
+        choice(
+          seq("--", /.*/),
+          // FIXME comments /- -/ are nested, which needs to be done in scanner.c
+          seq("/-", /([^-]|-+[^/])-/, "/"),
+        ),
+      ),
+
+
+    lamExpr: $ => seq(
+      choice("\\", "λ"),
+      repeat1($.identifier),
+      "=>",
+      $.typeExpr
+    ),
+    // hole, parenTypeExpression, record update
+    _atom: $ => choice($.varname, $.strLit, $.operator, seq("(", $.typeExpr, ")")),
+    _parg: $ => choice($._atom, seq("{{", $.typeExpr, "}}"), seq("{", $.typeExpr, "}")),
+    appExpr: $ => seq($._atom, repeat($._parg)),
+    qname: ($) => sep1(".", $.identifier),
+    strLit: $ => /"[^"]*"/,
+    doCaseLet: $ => seq("let", "(", $.term, ")", "=", $.typeExpr,
+      layout($, $._orAlt)),
+    caseAlt: $ => seq($.term, "=>", $.term),
+    _orAlt: $ => seq("|", $.caseAlt),
+    _doArrow: $ => seq("<-", $.typeExpr, optional(layout($, $._orAlt))),
+    doArrow: $ => seq($.term, optional($._doArrow)),
+    doLet: $ => seq("let", $.identifier, "=", $.term),
+    _doExpr: $ => choice(
+      $.doCaseLet,
+      $.doLet,
+      $.doArrow),
+    doBlock: $ => seq("do", layout($, $._doExpr)),
+    ifThen: ($) => seq("if", $.term, "then", $.term, "else", $.term),
+    _term2: ($) =>
+      choice(
+        // caseExpr
+        // caseLet
+        // caseLamExpr
+        $.lamExpr,
+        $.doBlock,
+        $.ifThen,
+        $.appExpr,
+      ),
+    term: ($) => prec.right(seq($._term2, repeat(seq("$", $._term2)))),
+
+    // varname is ident|uident|_, but we'll gloss over that
+    varname: ($) => $.identifier,
+
+
+    // abind/ibind/ebind in Parser.newt
+    binder: ($) =>
+      choice(
+        seq("(", $.identifier, ":", $.typeExpr, ")"),
+        // seq("(", $.typeExpr, ")"),
+        seq("{{", $.typeExpr, "}}"),
+        seq("{", $.identifier, ":", $.typeExpr, "}"),
+      ),
+    _arr: ($) => choice("->", "→"),
+    forall: ($) => seq("∀", repeat1($.identifier), ".", $.typeExpr),
+    binders: ($) => seq(choice($.varname, repeat1($.binder)), $._arr, $.typeExpr),
+    typeExpr: ($) => choice($.forall, $.binders, $.term),
+
+    // pitype: ($) =>
+    //   seq(
+    //     optional($.forall),
+    //     repeat(seq(repeat1(choice($.identifier, $.binder)), $._arr)),
+    //     $.identifier,
+    //   ),
+    sigDecl: ($) => seq($.identifier, ":", $.typeExpr),
+    defDecl: ($) => seq($.appExpr, "=", $.typeExpr),
+    dataDecl: ($) =>
+      seq(
+        "data",
+        $.identifier,
+        ":",
+        $.typeExpr,
+        optional(seq("where", layout($, $.conDef))),
+      ),
+    importDef: ($) => seq("import", $.qname),
+    conDef: ($) =>
+      seq(
+        $.identifier, // upper
+        ":",
+        $.typeExpr
+      ),
+    _decl: ($) =>
+      choice(
+        // mixfixDecl,
+        // ptypeDecl
+        // pfuncDecl
+        $.dataDecl,
+        // shortDataDecl
+        // classDecl
+        // instanceDecl
+        // recordDecl
+        // exportDecl
+        // deriveDecl
+        $.sigDecl,
+        $.defDecl,
+      ),
+    module: ($) =>
+      seq(
+        "module",
+        $.identifier,
+        repeat(seq($.semi, $.importDef)),
+        repeat(seq($.semi, $._decl)),
+      ),
+    // these are _way_ more generous in newt
+    operator: ($) => /[!#$%&*+.,/<=>?@\\^|-]+/,
+    identifier: ($) => /[A-Za-z_][\w']*|[,]|\+\+/,
+  },
+});