protected virtual StatementSequenceNode ParseStatementSequence(IStatementParentNode parent, Token token)
{
// PARSE: (<expression> ['.' [<statements>]])
StatementSequenceNode result = new StatementSequenceNode(parent);
ExpressionNode expression = this.ParseExpression(result, token);
if (expression == null)
{
this.ReportParserError(result, SemanticErrors.MissingExpression, token);
}
SpecialCharacterToken period = null;
token = this.GetNextTokenxx(Preference.Default);
if (Parser.IsStatementDelimiter(token))
{
period = (SpecialCharacterToken)token;
}
else
{
result.SetContents(expression, null, null);
this.ResidueToken = token;
return(result);
}
// ['.' [<statements>]])
token = this.GetNextTokenxx(Preference.NegativeSign);
if (token is EofToken)
{
result.SetContents(expression, period, null);
this.ResidueToken = token;
return(result);
}
if (Parser.IsBlockEndDelimiter(token))
{
result.SetContents(expression, period, null);
this.ResidueToken = token;
return(result);
}
else if (Parser.IsStatementDelimiter(token))
{
this.ReportParserError(result, SemanticErrors.MissingStatement, token);
result.SetContents(expression, period, null);
this.ResidueToken = token;
return(result);
}
StatementNode nextStatement = this.ParseStatement(result, token);
result.SetContents(expression, period, nextStatement);
return(result);
}
protected virtual ReturnStatementNode ParseReturnStatement(IStatementParentNode parent, ReturnOperatorToken returnOperator)
{
// PARSE: <return statement> ::= returnOperator <expression>
// Also: <statements> ::= <return statement> [’.’]
ReturnStatementNode result = new ReturnStatementNode(parent, returnOperator);
Token token = this.GetNextTokenxx(Preference.NegativeSign);
ExpressionNode expression = this.ParseExpression(result, token);
if (expression == null)
{
this.ReportParserError(result, SemanticErrors.MissingExpression, token);
}
SpecialCharacterToken period = null;
token = this.GetNextTokenxx(Preference.Default);
if (Parser.IsStatementDelimiter(token))
{
period = (SpecialCharacterToken)token;
token = this.GetNextTokenxx(Preference.Default);
}
result.SetContents(expression, period);
// Returns statement ... should have reached the end of the statement.
this.ResidueToken = token;
if (token is EofToken)
{
return(result); // OK
}
else if (Parser.IsBlockEndDelimiter(token))
{
return(result); // OK;
}
else if (Parser.IsStatementDelimiter(token))
{
this.ReportParserError(result, SemanticErrors.MissingStatement, token);
}
else
{
this.ReportParserError(result, SemanticErrors.CodeAfterReturnStatement, token);
}
return(result);
}
