support generator functions (#4620)

1 files changed, 146 insertions, 36 deletions

diff --git a/lib/ast.js b/lib/ast.js
index ead2c7d5..ea823b28 100644
--- a/lib/ast.js
+++ b/lib/ast.js
@@ -113,7 +113,9 @@ var AST_Node = DEFNODE("Node", "start end", {
     walk: function(visitor) {
         visitor.visit(this);
     },
-    _validate: noop,
+    _validate: function() {
+        if (this.TYPE == "Node") throw new Error("should not instantiate AST_Node");
+    },
     validate: function() {
         var ctor = this.CTOR;
         do {
@@ -187,6 +189,9 @@ AST_Node.disable_validation = function() {
 
 var AST_Statement = DEFNODE("Statement", null, {
     $documentation: "Base class of all statements",
+    _validate: function() {
+        if (this.TYPE == "Statement") throw new Error("should not instantiate AST_Statement");
+    },
 });
 
 var AST_Debugger = DEFNODE("Debugger", null, {
@@ -215,7 +220,7 @@ function validate_expression(value, prop, multiple, allow_spread, allow_hole) {
     if (value instanceof AST_Destructured) throw new Error(prop + " cannot " + multiple + " AST_Destructured");
     if (value instanceof AST_Hole && !allow_hole) throw new Error(prop + " cannot " + multiple + " AST_Hole");
     if (value instanceof AST_Spread && !allow_spread) throw new Error(prop + " cannot " + multiple + " AST_Spread");
-    if (value instanceof AST_Statement && !is_function(value)) {
+    if (value instanceof AST_Statement && !(value instanceof AST_LambdaExpression)) {
         throw new Error(prop + " cannot " + multiple + " AST_Statement");
     }
     if (value instanceof AST_SymbolDeclaration) {
@@ -265,6 +270,7 @@ var AST_BlockScope = DEFNODE("BlockScope", "enclosed functions make_def parent_s
         return this.parent_scope.resolve();
     },
     _validate: function() {
+        if (this.TYPE == "BlockScope") throw new Error("should not instantiate AST_BlockScope");
         if (this.parent_scope == null) return;
         if (!(this.parent_scope instanceof AST_BlockScope)) throw new Error("parent_scope must be AST_BlockScope");
         if (!(this.resolve() instanceof AST_Scope)) throw new Error("must be contained within AST_Scope");
@@ -289,9 +295,10 @@ var AST_Block = DEFNODE("Block", "body", {
         });
     },
     _validate: function() {
+        if (this.TYPE == "Block") throw new Error("should not instantiate AST_Block");
         this.body.forEach(function(node) {
             if (!(node instanceof AST_Statement)) throw new Error("body must be AST_Statement[]");
-            if (is_function(node)) throw new Error("body cannot contain AST_Function");
+            if (node instanceof AST_LambdaExpression) throw new Error("body cannot contain AST_LambdaExpression");
         });
     },
 }, AST_BlockScope);
@@ -306,8 +313,9 @@ var AST_StatementWithBody = DEFNODE("StatementWithBody", "body", {
         body: "[AST_Statement] the body; this should always be present, even if it's an AST_EmptyStatement"
     },
     _validate: function() {
+        if (this.TYPE == "StatementWithBody") throw new Error("should not instantiate AST_StatementWithBody");
         if (!(this.body instanceof AST_Statement)) throw new Error("body must be AST_Statement");
-        if (is_function(this.body)) throw new Error("body cannot be AST_Function");
+        if (this.body instanceof AST_LambdaExpression) throw new Error("body cannot be AST_LambdaExpression");
     },
 }, AST_BlockScope);
 
@@ -346,7 +354,10 @@ var AST_LabeledStatement = DEFNODE("LabeledStatement", "label", {
 }, AST_StatementWithBody);
 
 var AST_IterationStatement = DEFNODE("IterationStatement", null, {
-    $documentation: "Internal class.  All loops inherit from it."
+    $documentation: "Internal class.  All loops inherit from it.",
+    _validate: function() {
+        if (this.TYPE == "IterationStatement") throw new Error("should not instantiate AST_IterationStatement");
+    },
 }, AST_StatementWithBody);
 
 var AST_DWLoop = DEFNODE("DWLoop", "condition", {
@@ -355,6 +366,7 @@ var AST_DWLoop = DEFNODE("DWLoop", "condition", {
         condition: "[AST_Node] the loop condition.  Should not be instanceof AST_Statement"
     },
     _validate: function() {
+        if (this.TYPE == "DWLoop") throw new Error("should not instantiate AST_DWLoop");
         must_be_expression(this, "condition");
     },
 }, AST_IterationStatement);
@@ -401,7 +413,7 @@ var AST_For = DEFNODE("For", "init condition step", {
         if (this.init != null) {
             if (!(this.init instanceof AST_Node)) throw new Error("init must be AST_Node");
             if (this.init instanceof AST_Statement
-                && !(this.init instanceof AST_Definitions || is_function(this.init))) {
+                && !(this.init instanceof AST_Definitions || this.init instanceof AST_LambdaExpression)) {
                 throw new Error("init cannot be AST_Statement");
             }
         }
@@ -467,6 +479,9 @@ var AST_Scope = DEFNODE("Scope", "uses_eval uses_with", {
         return this.uses_eval || this.uses_with;
     },
     resolve: return_this,
+    _validate: function() {
+        if (this.TYPE == "Scope") throw new Error("should not instantiate AST_Scope");
+    },
 }, AST_Block);
 
 var AST_Toplevel = DEFNODE("Toplevel", "globals", {
@@ -517,8 +532,9 @@ var AST_Lambda = DEFNODE("Lambda", "argnames length_read rest uses_arguments", {
     $documentation: "Base class for functions",
     $propdoc: {
         argnames: "[(AST_DefaultValue|AST_Destructured|AST_SymbolFunarg)*] array of function arguments and/or destructured literals",
+        length_read: "[boolean/S] whether length property of this function is accessed",
         rest: "[(AST_Destructured|AST_SymbolFunarg)?] rest parameter, or null if absent",
-        uses_arguments: "[boolean/S] tells whether this function accesses the arguments array",
+        uses_arguments: "[boolean/S] whether this function accesses the arguments array",
     },
     each_argname: function(visit) {
         var tw = new TreeWalker(function(node) {
@@ -549,6 +565,7 @@ var AST_Lambda = DEFNODE("Lambda", "argnames length_read rest uses_arguments", {
         });
     },
     _validate: function() {
+        if (this.TYPE == "Lambda") throw new Error("should not instantiate AST_Lambda");
         this.argnames.forEach(function(node) {
             validate_destructured(node, function(node) {
                 if (!(node instanceof AST_SymbolFunarg)) throw new Error("argnames must be AST_SymbolFunarg[]");
@@ -567,12 +584,33 @@ var AST_Accessor = DEFNODE("Accessor", null, {
     },
 }, AST_Lambda);
 
+var AST_LambdaExpression = DEFNODE("LambdaExpression", "inlined", {
+    $documentation: "Base class for function expressions",
+    $propdoc: {
+        inlined: "[boolean/S] whether this function has been inlined",
+    },
+    _validate: function() {
+        if (this.TYPE == "LambdaExpression") throw new Error("should not instantiate AST_LambdaExpression");
+    },
+}, AST_Lambda);
+
 function is_arrow(node) {
-    return node instanceof AST_AsyncArrow || node instanceof AST_Arrow;
+    return node instanceof AST_Arrow || node instanceof AST_AsyncArrow;
+}
+
+function is_async(node) {
+    return node instanceof AST_AsyncArrow
+        || node instanceof AST_AsyncDefun
+        || node instanceof AST_AsyncFunction
+        || node instanceof AST_AsyncGeneratorDefun
+        || node instanceof AST_AsyncGeneratorFunction;
 }
 
-function is_function(node) {
-    return is_arrow(node) || node instanceof AST_AsyncFunction || node instanceof AST_Function;
+function is_generator(node) {
+    return node instanceof AST_AsyncGeneratorDefun
+        || node instanceof AST_AsyncGeneratorFunction
+        || node instanceof AST_GeneratorDefun
+        || node instanceof AST_GeneratorFunction;
 }
 
 function walk_lambda(node, tw) {
@@ -583,7 +621,7 @@ function walk_lambda(node, tw) {
     }
 }
 
-var AST_Arrow = DEFNODE("Arrow", "inlined value", {
+var AST_Arrow = DEFNODE("Arrow", "value", {
     $documentation: "An arrow function expression",
     $propdoc: {
         value: "[AST_Node?] simple return expression, or null if using function body.",
@@ -610,13 +648,9 @@ var AST_Arrow = DEFNODE("Arrow", "inlined value", {
             if (this.body.length) throw new Error("body must be empty if value exists");
         }
     },
-}, AST_Lambda);
+}, AST_LambdaExpression);
 
-function is_async(node) {
-    return node instanceof AST_AsyncArrow || node instanceof AST_AsyncDefun || node instanceof AST_AsyncFunction;
-}
-
-var AST_AsyncArrow = DEFNODE("AsyncArrow", "inlined value", {
+var AST_AsyncArrow = DEFNODE("AsyncArrow", "value", {
     $documentation: "An asynchronous arrow function expression",
     $propdoc: {
         value: "[AST_Node?] simple return expression, or null if using function body.",
@@ -643,9 +677,9 @@ var AST_AsyncArrow = DEFNODE("AsyncArrow", "inlined value", {
             if (this.body.length) throw new Error("body must be empty if value exists");
         }
     },
-}, AST_Lambda);
+}, AST_LambdaExpression);
 
-var AST_AsyncFunction = DEFNODE("AsyncFunction", "inlined name", {
+var AST_AsyncFunction = DEFNODE("AsyncFunction", "name", {
     $documentation: "An asynchronous function expression",
     $propdoc: {
         name: "[AST_SymbolLambda?] the name of this function",
@@ -655,10 +689,10 @@ var AST_AsyncFunction = DEFNODE("AsyncFunction", "inlined name", {
             if (!(this.name instanceof AST_SymbolLambda)) throw new Error("name must be AST_SymbolLambda");
         }
     },
-}, AST_Lambda);
+}, AST_LambdaExpression);
 
-var AST_Function = DEFNODE("Function", "inlined name", {
-    $documentation: "A function expression",
+var AST_AsyncGeneratorFunction = DEFNODE("AsyncGeneratorFunction", "name", {
+    $documentation: "An asynchronous generator function expression",
     $propdoc: {
         name: "[AST_SymbolLambda?] the name of this function",
     },
@@ -667,36 +701,67 @@ var AST_Function = DEFNODE("Function", "inlined name", {
             if (!(this.name instanceof AST_SymbolLambda)) throw new Error("name must be AST_SymbolLambda");
         }
     },
-}, AST_Lambda);
+}, AST_LambdaExpression);
 
-function is_defun(node) {
-    return node instanceof AST_AsyncDefun || node instanceof AST_Defun;
-}
+var AST_Function = DEFNODE("Function", "name", {
+    $documentation: "A function expression",
+    $propdoc: {
+        name: "[AST_SymbolLambda?] the name of this function",
+    },
+    _validate: function() {
+        if (this.name != null) {
+            if (!(this.name instanceof AST_SymbolLambda)) throw new Error("name must be AST_SymbolLambda");
+        }
+    },
+}, AST_LambdaExpression);
 
-var AST_AsyncDefun = DEFNODE("AsyncDefun", "inlined name", {
-    $documentation: "An asynchronous function definition",
+var AST_GeneratorFunction = DEFNODE("GeneratorFunction", "name", {
+    $documentation: "A generator function expression",
     $propdoc: {
-        name: "[AST_SymbolDefun] the name of this function",
+        name: "[AST_SymbolLambda?] the name of this function",
     },
     _validate: function() {
-        if (!(this.name instanceof AST_SymbolDefun)) throw new Error("name must be AST_SymbolDefun");
+        if (this.name != null) {
+            if (!(this.name instanceof AST_SymbolLambda)) throw new Error("name must be AST_SymbolLambda");
+        }
     },
-}, AST_Lambda);
+}, AST_LambdaExpression);
 
-var AST_Defun = DEFNODE("Defun", "inlined name", {
-    $documentation: "A function definition",
+var AST_LambdaDefinition = DEFNODE("LambdaDefinition", "inlined name", {
+    $documentation: "Base class for function definitions",
     $propdoc: {
+        inlined: "[boolean/S] whether this function has been inlined",
         name: "[AST_SymbolDefun] the name of this function",
     },
     _validate: function() {
+        if (this.TYPE == "LambdaDefinition") throw new Error("should not instantiate AST_LambdaDefinition");
         if (!(this.name instanceof AST_SymbolDefun)) throw new Error("name must be AST_SymbolDefun");
     },
 }, AST_Lambda);
 
+var AST_AsyncDefun = DEFNODE("AsyncDefun", null, {
+    $documentation: "An asynchronous function definition",
+}, AST_LambdaDefinition);
+
+var AST_AsyncGeneratorDefun = DEFNODE("AsyncGeneratorDefun", null, {
+    $documentation: "An asynchronous generator function definition",
+}, AST_LambdaDefinition);
+
+var AST_Defun = DEFNODE("Defun", null, {
+    $documentation: "A function definition",
+}, AST_LambdaDefinition);
+
+var AST_GeneratorDefun = DEFNODE("GeneratorDefun", null, {
+    $documentation: "A generator function definition",
+}, AST_LambdaDefinition);
+
 /* -----[ JUMPS ]----- */
 
 var AST_Jump = DEFNODE("Jump", null, {
-    $documentation: "Base class for “jumps” (for now that's `return`, `throw`, `break` and `continue`)"
+    $documentation: "Base class for “jumps” (for now that's `return`, `throw`, `break` and `continue`)",
+    _validate: function() {
+        if (this.TYPE == "Jump") throw new Error("should not instantiate AST_Jump");
+    },
 }, AST_Statement);
 
 var AST_Exit = DEFNODE("Exit", "value", {
@@ -709,7 +774,10 @@ var AST_Exit = DEFNODE("Exit", "value", {
         visitor.visit(node, function() {
             if (node.value) node.value.walk(visitor);
         });
-    }
+    },
+    _validate: function() {
+        if (this.TYPE == "Exit") throw new Error("should not instantiate AST_Exit");
+    },
 }, AST_Jump);
 
 var AST_Return = DEFNODE("Return", null, {
@@ -738,6 +806,7 @@ var AST_LoopControl = DEFNODE("LoopControl", "label", {
         });
     },
     _validate: function() {
+        if (this.TYPE == "LoopControl") throw new Error("should not instantiate AST_LoopControl");
         if (this.label != null) {
             if (!(this.label instanceof AST_LabelRef)) throw new Error("label must be AST_LabelRef");
         }
@@ -772,7 +841,7 @@ var AST_If = DEFNODE("If", "condition alternative", {
         must_be_expression(this, "condition");
         if (this.alternative != null) {
             if (!(this.alternative instanceof AST_Statement)) throw new Error("alternative must be AST_Statement");
-            if (is_function(this.alternative)) throw new error("alternative cannot be AST_Function");
+            if (this.alternative instanceof AST_LambdaExpression) throw new error("alternative cannot be AST_LambdaExpression");
         }
     },
 }, AST_StatementWithBody);
@@ -801,6 +870,9 @@ var AST_Switch = DEFNODE("Switch", "expression", {
 
 var AST_SwitchBranch = DEFNODE("SwitchBranch", null, {
     $documentation: "Base class for `switch` branches",
+    _validate: function() {
+        if (this.TYPE == "SwitchBranch") throw new Error("should not instantiate AST_SwitchBranch");
+    },
 }, AST_Block);
 
 var AST_Default = DEFNODE("Default", null, {
@@ -889,6 +961,7 @@ var AST_Definitions = DEFNODE("Definitions", "definitions", {
         });
     },
     _validate: function() {
+        if (this.TYPE == "Definitions") throw new Error("should not instantiate AST_Definitions");
         if (this.definitions.length < 1) throw new Error("must have at least one definition");
     },
 }, AST_Statement);
@@ -1036,6 +1109,7 @@ var AST_PropAccess = DEFNODE("PropAccess", "expression property", {
         return p;
     },
     _validate: function() {
+        if (this.TYPE == "PropAccess") throw new Error("should not instantiate AST_PropAccess");
         must_be_expression(this, "expression");
     },
 });
@@ -1096,6 +1170,7 @@ var AST_Unary = DEFNODE("Unary", "operator expression", {
         });
     },
     _validate: function() {
+        if (this.TYPE == "Unary") throw new Error("should not instantiate AST_Unary");
         if (typeof this.operator != "string") throw new Error("operator must be string");
         must_be_expression(this, "expression");
     },
@@ -1183,6 +1258,27 @@ var AST_Await = DEFNODE("Await", "expression", {
     },
 });
 
+var AST_Yield = DEFNODE("Yield", "expression nested", {
+    $documentation: "A yield expression",
+    $propdoc: {
+        expression: "[AST_Node?] return value for iterator, or null if undefined",
+        nested: "[boolean] whether to iterate over expression as generator",
+    },
+    walk: function(visitor) {
+        var node = this;
+        visitor.visit(node, function() {
+            if (node.expression) node.expression.walk(visitor);
+        });
+    },
+    _validate: function() {
+        if (this.expression != null) {
+            must_be_expression(this, "expression");
+        } else if (this.nested) {
+            throw new Error("yield* must contain expression");
+        }
+    },
+});
+
 /* -----[ LITERALS ]----- */
 
 var AST_Array = DEFNODE("Array", "elements", {
@@ -1208,6 +1304,9 @@ var AST_Destructured = DEFNODE("Destructured", "rest", {
     $propdoc: {
         rest: "[(AST_Destructured|AST_SymbolDeclaration|AST_SymbolRef)?] rest parameter, or null if absent",
     },
+    _validate: function() {
+        if (this.TYPE == "Destructured") throw new Error("should not instantiate AST_Destructured");
+    },
 });
 
 function validate_destructured(node, check, allow_default) {
@@ -1319,6 +1418,7 @@ var AST_ObjectProperty = DEFNODE("ObjectProperty", "key value", {
         });
     },
     _validate: function() {
+        if (this.TYPE == "ObjectProperty") throw new Error("should not instantiate AST_ObjectProperty");
         if (typeof this.key != "string") {
             if (!(this.key instanceof AST_Node)) throw new Error("key must be string or AST_Node");
             must_be_expression(this, "key");
@@ -1356,6 +1456,7 @@ var AST_Symbol = DEFNODE("Symbol", "scope name thedef", {
         thedef: "[SymbolDef/S] the definition of this symbol"
     },
     _validate: function() {
+        if (this.TYPE == "Symbol") throw new Error("should not instantiate AST_Symbol");
         if (typeof this.name != "string") throw new Error("name must be string");
     },
 });
@@ -1448,6 +1549,9 @@ var AST_Template = DEFNODE("Template", "expressions strings tag", {
 
 var AST_Constant = DEFNODE("Constant", null, {
     $documentation: "Base class for all constants",
+    _validate: function() {
+        if (this.TYPE == "Constant") throw new Error("should not instantiate AST_Constant");
+    },
 });
 
 var AST_String = DEFNODE("String", "value quote", {
@@ -1496,6 +1600,9 @@ var AST_RegExp = DEFNODE("RegExp", "value", {
 
 var AST_Atom = DEFNODE("Atom", null, {
     $documentation: "Base class for atoms",
+    _validate: function() {
+        if (this.TYPE == "Atom") throw new Error("should not instantiate AST_Atom");
+    },
 }, AST_Constant);
 
 var AST_Null = DEFNODE("Null", null, {
@@ -1525,6 +1632,9 @@ var AST_Infinity = DEFNODE("Infinity", null, {
 
 var AST_Boolean = DEFNODE("Boolean", null, {
     $documentation: "Base class for booleans",
+    _validate: function() {
+        if (this.TYPE == "Boolean") throw new Error("should not instantiate AST_Boolean");
+    },
 }, AST_Atom);
 
 var AST_False = DEFNODE("False", null, {