Add support for `%` operator in case guards (#96)

grammar.js

@@ -466,7 +466,8 @@ module.exports = grammar({
         binaryExpr(prec.left, 6, "*", $._case_clause_guard_expression),
         binaryExpr(prec.left, 6, "*.", $._case_clause_guard_expression),
         binaryExpr(prec.left, 6, "/", $._case_clause_guard_expression),
-        binaryExpr(prec.left, 6, "/.", $._case_clause_guard_expression)
+        binaryExpr(prec.left, 6, "/.", $._case_clause_guard_expression),
+        binaryExpr(prec.left, 6, "%", $._case_clause_guard_expression)
       ),
     _case_clause_guard_unit: ($) =>
       choice(

test/corpus/cases.txt

@@ -218,3 +218,38 @@ case var {
             (discard)))
         (record
           (constructor_name))))))
+
+================================================================================
+Case with int remainder in guard
+================================================================================
+
+case var {
+  _ if 11 % 2 == 0 -> True
+  _ -> False
+}
+
+--------------------------------------------------------------------------------
+
+(source_file
+  (case
+    (case_subjects
+      (identifier))
+    (case_clauses
+      (case_clause
+      (case_clause_patterns
+        (case_clause_pattern
+        (discard)))
+      (case_clause_guard
+        (binary_expression
+        (binary_expression
+            (integer)
+            (integer))
+        (integer)))
+      (record
+        (constructor_name)))
+      (case_clause
+      (case_clause_patterns
+        (case_clause_pattern
+        (discard)))
+      (record
+        (constructor_name))))))

test/highlight/cases.gleam

@@ -0,0 +1,11 @@
+pub fn case_with_remainder() {
+  case todo {
+    _ if 1 % 2 == 0 -> todo
+    //   ^ number
+    //     ^ operator
+    //       ^ number
+    //         ^ operator
+    //            ^ number
+    _ -> todo
+  }
+}