AstExpansion ParseSpread(DestructuringErrors refDestructuringErrors)
{
var startLoc = Start;
Next();
var argument = ParseMaybeAssign(false, refDestructuringErrors);
return(new AstExpansion(this, startLoc, _lastTokEnd, argument));
}
AstNode ParseForStatement(Position nodeStart)
{
Next();
EnterLexicalScope();
Expect(TokenType.ParenL);
if (Type == TokenType.Semi)
{
return(ParseFor(nodeStart, null));
}
var isLet = IsLet();
if (Type == TokenType.Var || Type == TokenType.Const || isLet)
{
var startLoc = Start;
var kind = isLet ? VariableKind.Let : ToVariableKind((string)Value);
Next();
var declarations = new StructList <AstVarDef>();
ParseVar(ref declarations, true, kind);
AstDefinitions init;
if (kind == VariableKind.Let)
{
init = new AstLet(this, startLoc, _lastTokEnd, ref declarations);
}
else if (kind == VariableKind.Const)
{
init = new AstConst(this, startLoc, _lastTokEnd, ref declarations);
}
else
{
init = new AstVar(this, startLoc, _lastTokEnd, ref declarations);
}
if ((Type == TokenType.In || Options.EcmaVersion >= 6 && IsContextual("of")) &&
init.Definitions.Count == 1 &&
!(kind != VariableKind.Var && init.Definitions[0].Value != null))
{
return(ParseForIn(nodeStart, init));
}
return(ParseFor(nodeStart, init));
}
else
{
var refDestructuringErrors = new DestructuringErrors();
var init = ParseExpression(true, refDestructuringErrors);
if (Type == TokenType.In || Options.EcmaVersion >= 6 && IsContextual("of"))
{
init = ToAssignable(init);
CheckLVal(init, false, null);
CheckPatternErrors(refDestructuringErrors, true);
return(ParseForIn(nodeStart, init));
}
CheckExpressionErrors(refDestructuringErrors, true);
return(ParseFor(nodeStart, init));
}
}
static bool CheckExpressionErrors([CanBeNull] DestructuringErrors refDestructuringErrors, bool andThrow = false)
{
var pos = refDestructuringErrors?.ShorthandAssign ?? default;
if (!andThrow)
{
return(pos.Line > 0);
}
if (pos.Line > 0)
{
Raise(pos, "Shorthand property assignments are valid only in destructuring patterns");
}
return(false);
}
static void CheckPatternErrors([CanBeNull] DestructuringErrors refDestructuringErrors, bool isAssign)
{
if (refDestructuringErrors == null)
{
return;
}
if (refDestructuringErrors.TrailingComma.Line > 0)
{
RaiseRecoverable(refDestructuringErrors.TrailingComma, "Comma is not permitted after the rest element");
}
var parens = isAssign ? refDestructuringErrors.ParenthesizedAssign : refDestructuringErrors.ParenthesizedBind;
if (parens.Line > 0)
{
RaiseRecoverable(parens, "Parenthesized pattern");
}
}
