/// <summary>
/// Parses string literal text, processes escaped sequences.
/// </summary>
/// <param name="buffer">Characters buffer to read from.</param>
/// <param name="start">Offset in <paramref name="buffer"/> of first character.</param>
/// <param name="length">Number of characters.</param>
/// <param name="tryprocess">Callback that handles escaped character sequences. Returns new buffer position in case the sequence was processed, otherwise <c>-1</c>.</param>
/// <param name="binary">Whether to force a binary string output.</param>
/// <returns>Parsed text, either <see cref="string"/> or <see cref="byte"/>[].</returns>
object ProcessStringText(char[] buffer, int start, int length, ProcessStringDelegate tryprocess, bool binary = false)
{
Debug.Assert(start >= 0);
Debug.Assert(length >= 0);
Debug.Assert(tryprocess != null);
if (length == 0)
{
return(string.Empty);
}
int to = start + length;
Debug.Assert(start >= 0);
Debug.Assert(to <= buffer.Length);
PhpStringBuilder lazyBuilder = null;
// find first backslash quickly
int index = start;
while (index < to && buffer[index] != '\\')
{
index++;
}
//
for (; index < to; index++)
{
var c = buffer[index];
if (c == '\\' && index + 1 < to)
{
// ensure string builder lazily
if (lazyBuilder == null)
{
lazyBuilder = new PhpStringBuilder(_encoding, binary, length);
lazyBuilder.Append(buffer, start, index - start);
}
int processed = tryprocess(buffer, index + 1, lazyBuilder);
if (processed > 0)
{
Debug.Assert(processed >= index + 1);
index = processed;
continue;
}
}
if (lazyBuilder != null)
{
lazyBuilder.Append(c);
}
}
//
return(lazyBuilder == null
? Intern(buffer, start, length)
: lazyBuilder.StringResult); // TODO: .Result; and handle String or byte[] properly
}
object GetTokenAsQuotedString(ProcessStringDelegate tryprocess, char quote)
{
// 1/ "..."
// 2/ b"..."
// 3/ ...
bool binary = false;
int start = token_start;
int end = token_end;
if (start == end)
{
return(string.Empty);
}
if (buffer[start] == 'b')
{
binary = true;
start++;
}
if (end - start >= 2 && buffer[start] == quote && buffer[end - 1] == quote)
{
// quoted
start++;
end--;
}
else
{
if (binary) // rollback
{
binary = false;
start--;
}
}
return(ProcessStringText(buffer, start, end - start, tryprocess, binary));
}
bool ProcessEndNowDoc(ProcessStringDelegate tryprocess)
{
BEGIN(LexicalStates.ST_END_HEREDOC);
int trail = LabelTrailLength();
int start = BufferTokenStart;
int length = TokenLength - _hereDocLabel.Length - trail;
string sourcetext = GetTokenSubstring(0, length, intern: false);
string text = tryprocess != null
? (string)ProcessStringText(buffer, start, length, tryprocess)
: sourcetext;
text = FixHeredocIndent(text);
// move back at the end of the heredoc label - yyless does not work properly (requires additional condition for the optional ';')
lookahead_index = token_end = lookahead_index - _hereDocLabel.Length - trail;
_tokenSemantics.Object = new KeyValuePair <string, string>(text, sourcetext);
//
return(text.Length != 0);
}
