// Parse a statement function.
// We basically save the generated expression parse tree in the symbol
// to be inserted whenever a reference to the statement function is made.
ParseNode KStatementFunction(IdentifierToken identToken)
{
string methodName = identToken.Name;
Symbol method = _localSymbols.Get(methodName);
if (method != null && method.Defined && method.IsMethod) {
_messages.Error(MessageCode.SUBFUNCDEFINED, String.Format("Statement function {0} already defined", methodName));
SkipToEndOfLine();
return null;
}
// Create a special symbol table just for this statement function
_stfSymbols = new SymbolCollection(_localSymbols);
// Parameter list expected
int altReturnCount = 0;
Collection<Symbol> parameters = ParseParameterDecl(_stfSymbols, SymScope.LOCAL, out altReturnCount);
if (altReturnCount > 0) {
_messages.Error(MessageCode.ALTRETURNNOTALLOWED, "Alternate return not permitted for statement functions");
}
if (method == null) {
method = _localSymbols.Add(methodName, new SymFullType(), SymClass.FUNCTION, null, _ls.LineNumber);
}
method.Class = SymClass.INLINE;
method.Parameters = parameters;
method.Linkage = SymLinkage.BYVAL;
method.Defined = true;
ExpectToken(TokenID.EQUOP);
method.InlineValue = Expression();
// Blow away the temporary symbol table now we're out of scope
_stfSymbols = null;
return null;
}
// Parse an identifier from the specified token and assign the corresponding
// symbol to the identifier parse node.
ParseNode ParseIdentifierFromToken(IdentifierToken identToken)
{
IdentifierParseNode node = ParseIdentifierParseNode();
if (node != null) {
Symbol sym = GetMakeSymbolForCurrentScope(identToken.Name);
if (sym == null) {
_messages.Error(MessageCode.UNDEFINEDVARIABLE, String.Format("Undefined identifier {0}", identToken.Name));
return null;
}
node.Symbol = sym;
sym.IsReferenced = true;
}
return node;
}