/// <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
  }
});