private static ParseResult TryParseIdentifier <TChars>(
ExpandedTokenData <TChars> token,
PipExecutionContext context,
ref int position,
out TChars identifier,
bool logErrors = true)
where TChars : struct, ICharSpan <TChars>
{
Contract.Requires(token.IsValid);
Contract.RequiresNotNull(context);
var pathTable = context.PathTable;
var text = token.Text;
if (text.Length == 0 || position == text.Length)
{
var updateToken = token.UpdateLineInformationForPosition(position);
identifier = default(TChars);
return(new ParseResult()
{
Status = ParseStatus.UnexpectedEmptyIdentifier,
Path = updateToken.Path.ToString(pathTable),
Line = updateToken.Line,
Position = updateToken.Position,
});
}
int firstPosition = position;
char firstChar = text[position];
if (!SymbolCharacters.IsValidStartChar(firstChar))
{
var updateToken = token.UpdateLineInformationForPosition(position);
identifier = default(TChars);
return(new ParseResult()
{
Status = ParseStatus.UnexpectedCharacterAtStartOfIdentifier,
Path = updateToken.Path.ToString(pathTable),
Line = updateToken.Line,
Position = updateToken.Position,
Text = firstChar.ToString(),
});
}
position++;
for (; position < text.Length; position++)
{
char ch = text[position];
if (!SymbolCharacters.IsValidChar(ch))
{
break;
}
}
identifier = text.Subsegment(firstPosition, position - firstPosition);
return(new ParseResult {
Status = ParseStatus.Success
});
}
/// <summary>
/// Parses a dotted identifier. All error logging is the responsibility of the caller
/// </summary>
/// <param name="token">The token to parse</param>
/// <param name="context">Context with tables.</param>
/// <param name="identifier">The parsed identifier if successful, null if not.</param>
public static ParseResult TryParse <TChars>(
ExpandedTokenData <TChars> token,
PipExecutionContext context,
out DottedIdentifier identifier)
where TChars : struct, ICharSpan <TChars>
{
Contract.Requires(token.IsValid);
Contract.RequiresNotNull(context);
PathTable pathTableForError = context.PathTable;
SymbolTable symbolTable = context.SymbolTable;
int position = 0;
var text = token.Text;
int textLength = text.Length;
identifier = null;
if (text.Length == 0)
{
return(new ParseResult()
{
Status = ParseStatus.InvalidDottedIdentifierCannotBeEmpty,
Path = token.Path.ToString(pathTableForError),
Line = token.Line,
Position = token.Position,
});
}
TChars id;
var parseIdenfierResult = TryParseIdentifier(token, context, ref position, out id);
if (parseIdenfierResult.Status != ParseStatus.Success)
{
return(parseIdenfierResult);
}
identifier = DottedIdentifier.Create(symbolTable, id);
DottedIdentifier currentIdentifier = identifier;
while (position < textLength)
{
if (text[position] == '.')
{
if (position == textLength - 1)
{
// Last char is a dot.
var updateToken = token.UpdateLineInformationForPosition(position);
identifier = null;
return(new ParseResult()
{
Status = ParseStatus.InvalidDottedIdentifierUnexpectedDot,
Path = updateToken.Path.ToString(pathTableForError),
Line = updateToken.Line,
Position = updateToken.Position,
Text = currentIdentifier != null?currentIdentifier.Head.ToString(symbolTable.StringTable) : string.Empty,
});
}
position++;
TChars currentId;
parseIdenfierResult = TryParseIdentifier(token, context, ref position, out currentId);
if (parseIdenfierResult.Status != ParseStatus.Success)
{
identifier = null;
return(parseIdenfierResult);
}
var tail = DottedIdentifier.Create(symbolTable, currentId);
currentIdentifier.m_tail = tail;
currentIdentifier = tail;
}
else
{
break;
}
}
if (position < textLength)
{
var updateToken = token.UpdateLineInformationForPosition(position);
identifier = null;
return(new ParseResult()
{
Status = ParseStatus.InvalidDottedIdentifierUnexpectedCharacter,
Path = updateToken.Path.ToString(pathTableForError),
Line = updateToken.Line,
Position = updateToken.Position,
Text = text[position].ToString(),
});
}
return(new ParseResult()
{
Status = ParseStatus.Success
});
}