Add for-in loops and math assignment operators to js grammar

examples/grammars/javascript.cc

@@ -22,6 +22,7 @@ namespace tree_sitter_examples {
             sym("switch_statement"),
             sym("while_statement"),
             sym("for_statement"),
+            sym("for_in_statement"),
             sym("break_statement"),
             sym("var_declaration"),
             sym("throw_statement"),
@@ -31,12 +32,20 @@ namespace tree_sitter_examples {
         { "statement_block", in_braces(err(repeat(sym("statement")))) },
         { "for_statement", seq({
             keyword("for"),
-            in_parens(seq({
+            in_parens(err(seq({
                 choice({
                     sym("var_declaration"),
                     sym("expression_statement") }),
                 sym("expression_statement"),
-                err(sym("expression")) })),
+                sym("expression") }))),
+            sym("statement") }) },
+        { "for_in_statement", seq({
+            keyword("for"),
+            in_parens(err(seq({
+                optional(keyword("var")),
+                sym("identifier"),
+                keyword("in"),
+                sym("expression") }))),
             sym("statement") }) },
         { "throw_statement", terminated(seq({
             keyword("throw"),
@@ -79,9 +88,11 @@ namespace tree_sitter_examples {
         { "break_statement", terminated(keyword("break")) },
         { "var_declaration", terminated(seq({
             keyword("var"),
-            comma_sep(err(choice({
-                sym("assignment"),
-                sym("identifier") }))) })) },
+            comma_sep(err(seq({
+                sym("identifier"),
+                optional(seq({
+                    str("="),
+                    sym("expression") })) }))) })) },
         { "expression_statement", terminated(err(sym("expression"))) },
         { "return_statement", terminated(seq({
             keyword("return"),
@@ -152,7 +163,12 @@ namespace tree_sitter_examples {
             choice({
                 sym("identifier"),
                 sym("property_access") }),
-            str("="),
+            choice({
+                str("="),
+                str("+="),
+                str("-="),
+                str("*="),
+                str("/=") }),
             sym("expression") })) },
         { "function_expression", seq({
             keyword("function"),

spec/runtime/languages/javascript/control_flow.txt

@@ -1,3 +1,18 @@
+==========================================
+parses multiple statements
+==========================================
+var x = {}, z, i = 0;
+firstFunction(x)
+secondFunction(x);
+---
+(program
+    (var_declaration
+        (identifier) (object)
+        (identifier)
+        (identifier) (number))
+    (expression_statement (function_call (identifier) (identifier)))
+    (expression_statement (function_call (identifier) (identifier))))
+
 ==========================================
 js parses if statements
 ==========================================
@@ -49,11 +64,27 @@ for (var i = 1; someCondition(i); i = next()) {
 }
 ---
 (program (for_statement
-    (var_declaration (assignment (identifier) (number)))
+    (var_declaration (identifier) (number))
     (expression_statement (function_call (identifier) (identifier)))
     (assignment (identifier) (function_call (identifier)))
     (statement_block (expression_statement (function_call (identifier))))))
 
+==========================================
+parses for-in loops
+==========================================
+for (var key in someObject)
+    doSomething();
+for (key in someObject)
+    doSomethingElse();
+---
+(program
+    (for_in_statement
+        (identifier) (identifier)
+        (expression_statement (function_call (identifier))))
+    (for_in_statement
+        (identifier) (identifier)
+        (expression_statement (function_call (identifier)))))
+
 ==========================================
 parses while loops
 ==========================================

spec/runtime/languages/javascript/errors.txt

@@ -32,7 +32,7 @@ moreStuff();
 (program
     (expression_statement (function_call (identifier)))
     (for_statement
-        (var_declaration (assignment (identifier) (number)))
+        (var_declaration (identifier) (number))
         (expression_statement (ERROR '*'))
         (math_op (identifier))
         (statement_block (expression_statement (ERROR '*'))))

spec/runtime/languages/javascript/literals.txt

@@ -22,21 +22,6 @@ theFunction('', "", 'single-quoted-string', "double-quoted-string");
 (program (expression_statement (function_call (identifier)
     (string) (string) (string) (string))))
 
-==========================================
-parses multiple statements
-==========================================
-var x = {}, z, i = 0;
-firstFunction(x)
-secondFunction(x);
----
-(program
-    (var_declaration
-        (assignment (identifier) (object))
-        (identifier)
-        (assignment (identifier) (number)))
-    (expression_statement (function_call (identifier) (identifier)))
-    (expression_statement (function_call (identifier) (identifier))))
-
 ==========================================
 parses function expressions
 ==========================================
@@ -47,11 +32,11 @@ var x = {
 };
 ---
 (program
-    (var_declaration (assignment
+    (var_declaration
         (identifier)
         (object (identifier) (function_expression
             (formal_parameters (identifier) (identifier))
-            (statement_block (var_declaration (assignment (identifier) (identifier)))))))))
+            (statement_block (var_declaration (identifier) (identifier)))))))
 
 ==========================================
 parses comments
@@ -72,14 +57,14 @@ var thing = {
 (program
     (comment)
     (comment)
-    (var_declaration (assignment (identifier) (object
+    (var_declaration (identifier) (object
         (comment)
         (comment)
         (identifier) (function_expression
             (formal_parameters (identifier) (comment))
             (statement_block
                 (comment)
-                (expression_statement (function_call (identifier)))))))))
+                (expression_statement (function_call (identifier))))))))
 
 ==========================================
 parses comments within expressions

spec/runtime/languages/javascript/operators.txt

@@ -13,12 +13,12 @@ parses constructor calls
 var x = new Node(5, new Node(3, null));
 ---
 (program (var_declaration
-    (assignment (identifier)
+    (identifier)
+    (constructor_call (function_call (identifier)
+        (number)
         (constructor_call (function_call (identifier)
             (number)
-            (constructor_call (function_call (identifier)
-                (number)
-                (null))))))))
+            (null)))))))
 
 ==========================================
 parses property access with dot notation
@@ -116,6 +116,20 @@ print(x in y)
     (identifier)
     (in_expression (identifier) (identifier)))))
 
+============================================
+parses assignment operators
+============================================
+x += 1;
+x -= 1;
+x *= 2;
+x /= 2;
+---
+(program
+    (expression_statement (assignment (identifier) (number)))
+    (expression_statement (assignment (identifier) (number)))
+    (expression_statement (assignment (identifier) (number)))
+    (expression_statement (assignment (identifier) (number))))
+
 ============================================
 parses property access and operators
 ============================================