initial commit

grammar.js

@@ -0,0 +1,106 @@
+const
+  newline = '\n',
+  space = ' ',
+  decimal = /[0-9]/
+
+module.exports = grammar({
+  name: 'hcl',
+
+  conflicts: $ => [
+      [$.body],
+  ],
+
+  extras: $ => [
+    $.comment,
+    /\s/,
+  ],
+
+  rules: {
+    config_file: $ => $.body,
+
+    body: $ => repeat1(seq(
+      choice(
+        $.attribute, 
+        $.block,
+      ),
+      repeat1(newline),
+    )),
+
+    attribute: $ => seq(
+      $.identifier, 
+      '=', 
+      $.expression
+    ),
+
+    block: $ => seq(
+      $.identifier,
+      repeat(choice($.string_lit, $.identifier)),
+      '{',
+      repeat1(newline),
+      optional($.body),
+      // newline is handled in body
+      '}',
+    ),
+
+    expression: $ => choice(
+      $.expr_term,
+      //$.operation,
+      //$.conditional,
+    ),
+
+    expr_term: $ => choice(
+      $.literal_value,
+      // $.collection_value,
+      // $.template_expr,
+      $.variable_expr,
+      // $.function_call,
+      // $.for_expr,
+      // seq($.expr_term, $.index),
+      // seq($.expr_term, $.get_attr),
+      // seq($.expr_term, $.splat),
+      // seq($.expr_term, $.splat),
+      seq('(', $.expression, ')'),
+    ),
+
+    literal_value: $ => choice(
+      $.numeric_lit,
+      $.string_lit,
+      'true',
+      'false',
+      'null',
+    ),
+
+    numeric_lit: $ => seq(
+      repeat1(decimal), 
+      optional(seq('.', repeat1(decimal))), 
+      optional(seq(choice('e', 'E'), optional(choice('+', '-')), repeat1(decimal))),
+    ),
+
+    variable_expr: $ => $.identifier,
+
+    // TODO: template expressions
+    //template_expr: $ => choice(
+      //$.quoted_template, 
+      //$.heredoc_template,
+    //),
+    //quoted_template: $ => seq('"', /\w+/, '"'),
+    //heredoc_template: $ => '',
+
+    // TODO: string_literals are special template literals
+    string_lit: $ => seq('"', /\w+/, '"'),
+
+    // TODO: unicode identifier
+    identifier: $ => /\w+/,
+
+    // http://stackoverflow.com/questions/13014947/regex-to-match-a-c-style-multiline-comment/36328890#36328890
+    comment: $ => token(choice(
+      seq('#', /.*/),
+      seq('//', /.*/),
+      seq(
+        '/*',
+        /[^*]*\*+([^/*][^*]*\*+)*/,
+        '/'
+      )
+    ))
+  }
+});