/// <remarks>
/// This method returns the expression before a specified offset.
/// That method is used in code completion to determine the expression given
/// to the parser for type resolve.
/// </remarks>
public static string GetExpressionBeforeOffset(TextArea textArea, int initialOffset)
{
Document document = textArea.Document;
int offset = initialOffset;
while (offset - 1 > 0)
{
switch (document.GetCharAt(offset - 1))
{
case '\n':
case '\r':
case '}':
goto done;
// offset = SearchBracketBackward(document, offset - 2, '{','}');
// break;
case ']':
offset = SearchBracketBackward(document, offset - 2, '[', ']');
break;
case ')':
offset = SearchBracketBackward(document, offset - 2, '(', ')');
break;
case '.':
--offset;
break;
case '"':
if (offset < initialOffset - 1)
{
return(null);
}
return("\"\"");
case '\'':
if (offset < initialOffset - 1)
{
return(null);
}
return("'a'");
case '>':
if (document.GetCharAt(offset - 2) == '-')
{
offset -= 2;
break;
}
goto done;
default:
if (Char.IsWhiteSpace(document.GetCharAt(offset - 1)))
{
--offset;
break;
}
int start = offset - 1;
if (!IsLetterDigitOrUnderscore(document.GetCharAt(start)))
{
goto done;
}
while (start > 0 && IsLetterDigitOrUnderscore(document.GetCharAt(start - 1)))
{
--start;
}
string word = document.GetText(start, offset - start).Trim();
switch (word)
{
case "ref":
case "out":
case "in":
case "return":
case "throw":
case "case":
goto done;
}
if (word.Length > 0 && !IsLetterDigitOrUnderscore(word[0]))
{
goto done;
}
offset = start;
break;
}
}
done:
//// simple exit fails when : is inside comment line or any other character
//// we have to check if we got several ids in resulting line, which usually happens when
//// id. is typed on next line after comment one
//// Would be better if lexer would parse properly such expressions. However this will cause
//// modifications in this area too - to get full comment line and remove it afterwards
if (offset < 0)
{
return(string.Empty);
}
string resText = document.GetText(offset, textArea.Caret.Offset - offset).Trim();
int pos = resText.LastIndexOf('\n');
if (pos >= 0)
{
offset += pos + 1;
//// whitespaces and tabs, which might be inside, will be skipped by trim below
}
string expression = document.GetText(offset, textArea.Caret.Offset - offset).Trim();
return(expression);
}
public static string GetLineAsString(Document document, int lineNumber)
{
LineSegment line = document.GetLineSegment(lineNumber);
return(document.GetText(line.Offset, line.Length));
}