Add support for terraform

Author: tpkessler

grammar.js

@@ -49,6 +49,125 @@ module.exports = grammar(terra, {
       'end'
     ),
 
+    
+    terraform_function_definition: ($) => seq(
+      'terraform',
+      $._terraform_function_body      
+    ),
+
+    terraform_function_implementation: ($) => seq(
+      'terraform',
+      field('name', $._function_name),
+      $._terraform_function_body
+    ),
+
+    _local_terraform_function_implementation: ($) => seq(
+      'local',
+      'terraform',
+      field('name', choice($.identifier, $.escape_expression)),
+      $._terraform_function_body
+    ),
+
+    _terraform_function_body: ($) => seq(
+      field('parameters', $.terraform_function_parameters),
+      optional(field('concepts', $.type_constraints)),
+      field('body', optional_block($)),
+      'end'
+    ),
+
+    terraform_function_parameters: ($) => seq(
+      '(',
+      optional($._terraform_parameter_list),
+      ')',
+    ),
+
+    type_constraints: ($) => seq(
+      'where',
+      '{',
+      optional($._constrained_types_list),
+      '}'
+    ),
+
+    _terraform_parameter_list: ($) => choice(
+      seq(
+        list_seq(
+          choice(
+            $._typed_declaration,
+            $.identifier,
+            $.escape_expression,
+          ),
+          ','
+        ),
+        optional(seq(',', $.terraform_vararg_expression))
+      ),
+      $.terraform_vararg_expression
+    ),
+
+    terraform_vararg_expression: ($) => seq(
+      field('name', $.identifier),
+      $.vararg_expression
+    ),
+
+    _constrained_types_list: ($) => list_seq(
+      choice(
+        $.identifier,
+        seq($.identifier, ':', choice($.string, $.number, $._type_specifier)),
+      ),
+      ','
+    ),
+
+    concept_implementation: ($) => seq(
+      'concept',
+      field('name', $._function_name),
+      $._concept_body,
+    ),
+
+    _local_concept_implementation: ($) => seq(
+      'local',
+      'concept',
+      field('name', choice($.identifier, $.escape_expression)),
+      $._concept_body,
+    ),
+
+    _regular_concept_body: ($) => seq(
+      field('body', optional_block($)),
+      'end'
+    ),
+
+    _parametrized_concept_body: ($) => seq(
+      field(
+        'parameters',
+        seq('(', optional(list_seq($.expression, ',')), ')')
+      ),
+      field('concepts', $.type_constraints),
+      field('body', optional_block($)),
+      'end'
+    ),
+
+    _concept_body: ($) => choice(
+      $._regular_concept_body,
+      $._parametrized_concept_body,
+    ),
+
+    declaration: ($, old) => choice(
+      old,
+      $.terraform_function_implementation,
+      alias(
+        $._local_terraform_function_implementation,
+        $.terraform_function_implementation
+      ),
+      $.concept_implementation,
+      alias(
+        $._local_concept_implementation,
+        $.concept_implementation
+      ),
+    ),
+
+    expression: ($, old) => choice(
+      old,
+      $.terraform_function_definition,
+    ),
+
     statement: ($, old) => choice(
       old,
       $.test_statement,

queries/highlights.scm

@@ -22,3 +22,31 @@
   "end"
 ] @keyword)
 
+(type_constraints
+[
+  "where"
+] @keyword)
+
+(terraform_function_definition
+[
+  "terraform"
+  "end"
+] @keyword)
+
+(terraform_function_implementation
+[
+  "terraform"
+  "end"
+] @keyword)
+
+(terraform_function_implementation
+[
+  "terraform"
+  "end"
+] @keyword)
+
+(concept_implementation
+[
+  "concept"
+  "end"
+] @keyword)