// Block IF
ParseNode KBlockIf(ParseNode expr)
{
ConditionalParseNode node = new ConditionalParseNode();
TokenID id;
do {
ParseNode labelNode;
CollectionParseNode statements = new CollectionParseNode();
SimpleToken token = _ls.GetKeyword();
++_blockDepth;
while (!IsEndOfIfBlock(token.ID)) {
labelNode = CheckLabel();
if (labelNode != null) {
statements.Add(labelNode);
}
ParseNode subnode = Statement(token);
if (subnode != null) {
statements.Add(MarkLine());
statements.Add(subnode);
}
ExpectEndOfLine();
token = _ls.GetKeyword();
}
--_blockDepth;
// Labels on terminators are valid so we need
// to check for and add those.
labelNode = CheckLabel();
if (labelNode != null) {
statements.Add(labelNode);
}
node.Add(expr, statements);
id = token.ID;
if (id == TokenID.KELSEIF) {
ExpectToken(TokenID.LPAREN);
expr = Expression();
ExpectToken(TokenID.RPAREN);
ExpectToken(TokenID.KTHEN);
ExpectEndOfLine();
} else if (id == TokenID.KELSE) {
// We mark the end of the sequence of IF blocks with
// a null expression.
expr = null;
ExpectEndOfLine();
}
} while(id == TokenID.KELSEIF || id == TokenID.KELSE);
_ls.BackToken();
ExpectToken(TokenID.KENDIF);
return node;
}
// Logical IF
ParseNode KLogicalIf(ParseNode expr)
{
ConditionalParseNode node = new ConditionalParseNode();
_parsingIf = true;
CollectionParseNode body = new CollectionParseNode();
body.Add(Statement(_ls.GetKeyword()));
_parsingIf = false;
node.Add(expr, body);
return node;
}
// Parse the body of a standard DO or DO WHILE loop.
CollectionParseNode ParseDoBody(SymbolParseNode endLabelNode)
{
CollectionParseNode statements = new CollectionParseNode();
bool loopDone = false;
SimpleToken token = _ls.GetKeyword();
++_blockDepth;
do {
ParseNode labelNode = CheckLabel();
if (labelNode != null) {
statements.Add(labelNode);
}
if (token.ID == TokenID.KENDDO) {
_messages.Warning(MessageCode.NONSTANDARDENDDO, 4, "Use of ENDDO is non-standard");
loopDone = true;
break;
}
statements.Add(MarkLine());
ParseNode subnode = Statement(token);
if (subnode != null) {
statements.Add(subnode);
}
if (_ls.HasLabel && endLabelNode != null && _ls.Label == endLabelNode.Symbol.Name) {
loopDone = true;
break;
}
ExpectEndOfLine();
token = _ls.GetKeyword();
} while (token.ID != TokenID.ENDOFFILE);
--_blockDepth;
if (!loopDone) {
_messages.Error(MessageCode.MISSINGDOENDLABEL, "End label for DO loop not found");
}
return statements;
}
