/// <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
}
protected object GetTokenAsSinglyQuotedString(string text, Encoding /*!*/ encoding, bool forceBinaryString)
{
PhpStringBuilder result = new PhpStringBuilder(encoding, forceBinaryString, TokenLength);
int pos = 1;
char c;
while (pos < text.Length)
{
c = text[pos++];
if (c == '\\' && pos < text.Length)
{
switch (c = text[pos++])
{
case '\\':
case '\'':
result.Append(c);
break;
default:
result.Append('\\');
result.Append(c);
break;
}
}
else
{
if (c == '\'')
{
break;
}
result.Append(c);
}
}
return(result.Result);
}
int _processDoubleQuotedString(char[] buffer, int pos, PhpStringBuilder result)
{
switch (buffer[pos])
{
case 'n':
result.Append('\n');
return(pos);
case 'r':
result.Append('\r');
return(pos);
case 't':
result.Append('\t');
return(pos);
case 'v':
result.Append('\v');
return(pos);
case 'e':
result.Append((char)0x1B);
return(pos);
case 'f':
result.Append('\f');
return(pos);
case '\\':
case '$':
case '"':
result.Append(buffer[pos]);
return(pos);
case '`':
if (CurrentLexicalState == LexicalStates.ST_IN_SHELL)
{
result.Append(buffer[pos]);
return(pos);
}
break;
case 'u':
if (EnableUtfCodepoints)
{
pos++;
result.Append(ParseCodePoint(buffer, ref pos, 4));
return(pos - 1);
}
else
{
break;
}
case 'x':
{
// \x[0-9A-Fa-f]{1,2}
int digit;
if ((digit = Convert.AlphaNumericToDigit(buffer[++pos])) < 16)
{
int hex_code = digit;
if ((digit = Convert.AlphaNumericToDigit(buffer[++pos])) < 16)
{
hex_code = (hex_code << 4) + digit;
}
else
{
pos--; // rollback
}
result.Append((byte)hex_code);
return(pos);
}
break;
}
default:
{
// \[0-7]{1,3}
int digit;
if ((digit = Convert.NumericToDigit(buffer[pos])) < 8) // 1
{
int octal_code = digit;
if ((digit = Convert.NumericToDigit(buffer[++pos])) < 8) // 2
{
octal_code = (octal_code << 3) + digit;
if ((digit = Convert.NumericToDigit(buffer[++pos])) < 8) // 3
{
octal_code = (octal_code << 3) + digit;
}
else
{
pos--; // rollback
}
}
else
{
pos--; // rollback
}
result.Append((byte)octal_code);
return(pos);
}
break;
}
}
// not handled:
return(-1);
}
protected object ProcessEscapedString(string text, Encoding /*!*/ encoding, bool forceBinaryString)
{
if (text.Length == 0)
{
return(string.Empty);
}
PhpStringBuilder result = new PhpStringBuilder(encoding, forceBinaryString, text.Length);
int pos = 0;
char c;
while (pos < text.Length)
{
c = text[pos++];
if (c == '\\' && pos < text.Length)
{
switch (c = text[pos++])
{
case 'n':
result.Append('\n');
break;
case 'r':
result.Append('\r');
break;
case 't':
result.Append('\t');
break;
case '\\':
case '$':
case '"':
result.Append(c);
break;
case 'C':
//if (!inUnicodeString) goto default;
result.Append(ParseCodePointName(ref pos));
break;
case 'u':
case 'U':
//if (!inUnicodeString) goto default;
result.Append(ParseCodePoint(c == 'u' ? 4 : 6, ref pos));
break;
case 'x':
{
int digit;
if (pos < text.Length && (digit = Convert.AlphaNumericToDigit(text[pos])) < 16)
{
int hex_code = digit;
pos++;
if (pos < text.Length && (digit = Convert.AlphaNumericToDigit(text[pos])) < 16)
{
pos++;
hex_code = (hex_code << 4) + digit;
}
//encodeBytes[0] = (byte)hex_code;
//result.Append(encodeChars, 0, encoding.GetChars(encodeBytes, 0, 1, encodeChars, 0));
result.Append((byte)hex_code);
}
else
{
result.Append('\\');
result.Append('x');
}
break;
}
default:
{
int digit;
if ((digit = Convert.NumericToDigit(c)) < 8)
{
int octal_code = digit;
if (pos < text.Length && (digit = Convert.NumericToDigit(text[pos])) < 8)
{
octal_code = (octal_code << 3) + digit;
pos++;
if (pos < text.Length && (digit = Convert.NumericToDigit(text[pos])) < 8)
{
pos++;
octal_code = (octal_code << 3) + digit;
}
}
//encodeBytes[0] = (byte)octal_code;
//result.Append(encodeChars, 0, encoding.GetChars(encodeBytes, 0, 1, encodeChars, 0));
result.Append((byte)octal_code);
}
else
{
result.Append('\\');
result.Append(c);
}
break;
}
}
}
else
{
result.Append(c);
}
}
return(result.Result);
}