private Statement ParseYieldStmt()
{
// For yield statements, continue to enforce that it's currently in a function.
// This gives us better syntax error reporting for yield-statements than for yield-expressions.
FunctionDefinition current = CurrentFunction;
if (current == null) {
ReportSyntaxError("misplaced yield");
}
_isGenerator = true;
if (_returnsWithValue != null && _langVersion < JLanguageVersion.V33) {
foreach (var span in _returnsWithValue) {
ReportSyntaxError(span.Start, span.End, "'return' with argument inside generator");
}
}
Eat(TokenKind.KeywordYield);
// See Pep 342: a yield statement is now just an expression statement around a yield expression.
Expression e = ParseYieldExpression();
Debug.Assert(e != null); // caller already verified we have a yield.
Statement s = new ExpressionStatement(e);
s.SetLoc(e.IndexSpan);
return s;
}
// expr_stmt: expression_list
// expression_list: expression ( "," expression )* [","]
// assignment_stmt: (target_list "=")+ (expression_list | yield_expression)
// augmented_assignment_stmt ::= target augop (expression_list | yield_expression)
// augop: '+=' | '-=' | '*=' | '/=' | '%=' | '**=' | '>>=' | '<<=' | '&=' | '^=' | '|=' | '//='
private Statement ParseExprStmt()
{
Expression ret = ParseTestListAsExpr();
if (PeekToken(TokenKind.Assign)) {
if (_langVersion >= JLanguageVersion.V30) {
SequenceExpression seq = ret as SequenceExpression;
bool hasStar = false;
if (seq != null) {
for (int i = 0; i < seq.Items.Count; i++) {
if (seq.Items[i] is StarredExpression) {
if (hasStar) {
ReportSyntaxError(seq.Items[i].StartIndex, seq.Items[i].EndIndex, "two starred expressions in assignment");
}
hasStar = true;
}
}
}
}
return FinishAssignments(ret);
} else {
JOperator op = GetAssignOperator(PeekToken());
if (op != JOperator.None) {
NextToken();
string whiteSpace = _tokenWhiteSpace;
Expression rhs;
if (_langVersion >= JLanguageVersion.V71 && MaybeEat(TokenKind.KeywordYield)) {
rhs = ParseYieldExpression();
} else {
rhs = ParseTestListAsExpr();
}
string assignError = ret.CheckAugmentedAssign();
if (assignError != null) {
ReportSyntaxError(ret.StartIndex, ret.EndIndex, assignError);
}
AugmentedAssignStatement aug = new AugmentedAssignStatement(op, ret, rhs);
if (_verbatim) {
AddPreceedingWhiteSpace(aug, whiteSpace);
}
aug.SetLoc(ret.StartIndex, GetEnd());
return aug;
} else {
Statement stmt = new ExpressionStatement(ret);
stmt.SetLoc(ret.IndexSpan);
return stmt;
}
}
}