internal override string CheckAssign()
{
if (Items.Count == 0)
{
return("can't assign to ()");
}
for (int i = 0; i < Items.Count; i++)
{
Expression e = Items[i];
if (e.CheckAssign() != null)
{
// we don't return the same message here as CPython doesn't seem to either,
// for example ((yield a), 2,3) = (2,3,4) gives a different error than
// a = yield 3 = yield 4.
return("can't assign to " + e.NodeName);
}
}
return(null);
}
private Statement FinishAssignments(Expression right) {
List<Expression> left = null;
Expression singleLeft = null;
while (MaybeEat(TokenKind.Assign)) {
string assignError = right.CheckAssign();
if (assignError != null) {
ReportSyntaxError(right.StartIndex, right.EndIndex, assignError, ErrorCodes.SyntaxError | ErrorCodes.NoCaret);
}
if (singleLeft == null) {
singleLeft = right;
} else {
if (left == null) {
left = new List<Expression>();
left.Add(singleLeft);
}
left.Add(right);
}
if (MaybeEat(TokenKind.KeywordYield)) {
right = ParseYieldExpression();
} else {
right = ParseTestListAsExpr();
}
}
if (left != null) {
Debug.Assert(left.Count > 0);
AssignmentStatement assign = new AssignmentStatement(left.ToArray(), right);
assign.SetLoc(_globalParent, left[0].StartIndex, right.EndIndex);
return assign;
} else {
Debug.Assert(singleLeft != null);
AssignmentStatement assign = new AssignmentStatement(new[] { singleLeft }, right);
assign.SetLoc(_globalParent, singleLeft.StartIndex, right.EndIndex);
return assign;
}
}
internal override string CheckAssign()
{
return(Value.CheckAssign());
}
private Statement FinishAssignments(Expression right) {
List<Expression> left = new List<Expression>();
while (MaybeEat(TokenKind.Assign)) {
string assignError = right.CheckAssign();
if (assignError != null) {
ReportSyntaxError(right.Span.Start, right.Span.End, assignError, ErrorCodes.SyntaxError);
}
left.Add(right);
if (MaybeEat(TokenKind.KeywordYield)) {
right = ParseYieldExpression();
} else {
bool trailingComma;
var exprs = ParseExpressionList(out trailingComma);
if (exprs.Count == 0) {
ReportSyntaxError(left[0].Start, left[0].End, "invalid syntax");
}
right = MakeTupleOrExpr(exprs, trailingComma);
}
}
Debug.Assert(left.Count > 0);
AssignmentStatement assign = new AssignmentStatement(left.ToArray(), right);
assign.SetLoc(left[0].Start, right.End);
return assign;
}
internal override string CheckAssign()
{
return(_expression.CheckAssign());
}
