/// <summary>
/// Determines whether a particular character is valid as the first character of an atom.
/// </summary>
public static bool IsValidIdentifierAtomStartChar(char value)
{
return(SymbolCharacters.IsValidStartChar(value));
}
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
});
}
