Add subscript operator

grammar.coffee

@@ -199,7 +199,8 @@ module.exports =
         @identifier,
         @assignment,
         @field_access,
-        @deref_field_access)
+        @deref_field_access,
+        @subscript_access)
 
       deref: -> prec(10, seq("*", @expression))
       address_of: -> prec(10, seq("&", @expression))
@@ -210,6 +211,9 @@ module.exports =
       deref_field_access: -> seq(
         @expression, "->", @identifier)
 
+      subscript_access: -> seq(
+        @expression, "[", @expression, "]")
+
       function_call: -> seq(
         @expression, "(", err(commaSep(@expression)), ")")
 
@@ -242,7 +246,8 @@ module.exports =
           @deref,
           @identifier,
           @field_access,
-          @deref_field_access),
+          @deref_field_access,
+          @subscript_access),
         "=",
         @expression))
 

grammar_test/expressions.txt

@@ -39,6 +39,7 @@ Field access
 int main() {
   s.data1;
   p->data2;
+  q[data3];
 }
 
 ---
@@ -46,7 +47,8 @@ int main() {
 (function_declaration (identifier) (identifier) (formal_parameters)
   (statement_block
     (expression_statement (field_access (identifier) (identifier)))
-    (expression_statement (deref_field_access (identifier) (identifier)))))
+    (expression_statement (deref_field_access (identifier) (identifier)))
+    (expression_statement (subscript_access (identifier) (identifier)))))
 
 ============================================
 Boolean operators
@@ -102,6 +104,7 @@ int main() {
   b = *c = 2;
   d.e = 3;
   f->g = 4;
+  h[i] = j;
 }
 
 ---
@@ -111,7 +114,8 @@ int main() {
     (var_declaration (storage_class) (identifier) (var_assignment (identifier) (number)))
     (expression_statement (assignment (identifier) (assignment (deref (identifier)) (number))))
     (expression_statement (assignment (field_access (identifier) (identifier)) (number)))
-    (expression_statement (assignment (deref_field_access (identifier) (identifier)) (number)))))
+    (expression_statement (assignment (deref_field_access (identifier) (identifier)) (number)))
+    (expression_statement (assignment (subscript_access (identifier) (identifier)) (identifier)))))
 
 ============================================
 Pointer operations