private Statement ParseYieldStmt()
{
NextToken();
Location start = GetStart();
FunctionDefinition current = CurrentFunction;
int yieldId = 0;
if (current == null) {
ReportSyntaxError("'yield' outside function");
} else {
yieldId = current.YieldCount++;
}
Expression e = ParseTestListAsExpr(false);
YieldStatement ret = new YieldStatement(e, yieldId);
ret.SetLoc(GetExternal(), start, GetEnd());
return ret;
}
private Expression ParseGeneratorExpression(Expression test)
{
ForStatement root = ParseGenExprFor();
Statement current = root;
for (; ; ) {
if (PeekToken(Tokens.KeywordForToken)) {
current = NestGenExpr(current, ParseGenExprFor());
} else if (PeekToken(Tokens.KeywordIfToken)) {
current = NestGenExpr(current, ParseGenExprIf());
} else {
YieldStatement ys = new YieldStatement(test, 0);
ys.SetLoc(GetExternal(), test.Start, test.End);
NestGenExpr(current, ys);
break;
}
}
SymbolId fname = SymbolTable.StringToId("__gen_" + System.Threading.Interlocked.Increment(ref genexp_counter));
NameExpression pname = new NameExpression(SymbolTable.GeneratorParmName);
FunctionDefinition func = new FunctionDefinition(fname, new Expression[] { pname }, new Expression[] { }, FunctionAttributes.None, root, context.SourceFile);
func.YieldCount = 1;
func.SetLoc(GetExternal(), root.Start, GetEnd());
func.Header = root.End;
// Transform the root "for" statement
Expression outermost = root.List;
root.List = pname;
CallExpression gexp = FinishCallExpr(new NameExpression(fname), new Arg(outermost));
CallExpression iter = FinishCallExpr(new NameExpression(SymbolTable.Iter), new Arg(gexp));
GeneratorExpression ret = new GeneratorExpression(func, iter);
ret.SetLoc(GetExternal(), root.Start, GetEnd());
return ret;
}