public ExpressionResult FindExpression(string text, int offset)
{
Init(text, offset);
ExpressionFinder p = new ExpressionFinder();
lexer = ParserFactory.CreateLexer(SupportedLanguage.VBNet, new StringReader(text));
Token t = lexer.NextToken();
// put all tokens in front of targetPosition into the EF-Parser
while (t.EndLocation < targetPosition)
{
p.InformToken(t);
t = lexer.NextToken();
}
// put current token into EF-Parser if it cannot be continued (is simple operator)
if (t.EndLocation == targetPosition && ((t.Kind <= Tokens.ColonAssign && t.Kind > Tokens.Identifier) || t.Kind == Tokens.EOL))
{
p.InformToken(t);
t = lexer.NextToken();
}
// make sure semantic actions are executed
p.Advance();
// remember current state, we'll use it to determine the context
var block = p.CurrentBlock;
ExpressionContext context = p.IsIdentifierExpected && !p.IsMissingModifier ? ExpressionContext.IdentifierExpected : GetContext(block);
BitArray expectedSet;
try {
expectedSet = p.GetExpectedSet();
} catch (InvalidOperationException) {
expectedSet = null;
}
// put current token into EF-Parser
if (t.Location < targetPosition)
{
p.InformToken(t);
}
if (p.Errors.Any())
{
foreach (var e in p.Errors)
{
LoggingService.Warn("not expected: " + e);
}
}
if (p.NextTokenIsPotentialStartOfExpression)
{
return(new ExpressionResult("", new DomRegion(targetPosition.Line, targetPosition.Column), context, expectedSet));
}
int lastExpressionStartOffset = LocationToOffset(p.CurrentBlock.lastExpressionStart);
if (lastExpressionStartOffset < 0)
{
return(new ExpressionResult("", new DomRegion(targetPosition.Line, targetPosition.Column), context, expectedSet));
}
return(MakeResult(text, lastExpressionStartOffset, offset, context, expectedSet));
}