feat: add basic tree-sitter

grammar.js

@@ -0,0 +1,56 @@
+/// <reference types="tree-sitter-cli/dsl" />
+// @ts-check
+
+module.exports = grammar({
+  name: "noil",
+
+  extras: $ => [
+    /[ \t]+/, // skip whitespace but not newlines
+  ],
+
+  rules: {
+    source_file: $ => repeat($.line),
+
+    line: $ => choice(
+      $.operation_line,
+      $.operation_only_line,
+      $.mapping_line,
+      $.path_only_line,
+      $.empty_line
+    ),
+
+    empty_line: _ => "\n",
+
+    path_only_line: $ => seq(
+      ":",
+      field("path", $.file_path),
+      "\n"
+    ),
+
+    mapping_line: $ => seq(
+      field("prefix", $.prefix),
+      ":",
+      field("path", $.file_path),
+      "\n"
+    ),
+
+    operation_line: $ => seq(
+      field("operation", $.operation),
+      field("prefix", $.prefix),
+      ":",
+      field("path", $.file_path),
+      "\n"
+    ),
+
+    operation_only_line: $ => seq(
+      field("operation", $.operation),
+      ":",
+      field("path", $.file_path),
+      "\n"
+    ),
+
+    prefix: _ => /[a-z0-9]+/,           // allow lowercase alphanumeric
+    operation: _ => /[A-Z]+/,           // must be all uppercase
+    file_path: _ => /[^ \t\n][^\n]*/,   // must not start with space or newline
+  }
+});