private static char GetUnicode(StringEnumerator se, int maxDigits)
{
var code = 0;
for (var count = 0; count < maxDigits; count++)
{
var digitCode = se.Peek();
if (digitCode >= '0' && digitCode <= '9')
{
digitCode = digitCode - '0';
}
else if (digitCode >= 'a' && digitCode <= 'f')
{
digitCode = digitCode - 'a' + 10;
}
else if (digitCode >= 'A' && digitCode <= 'F')
{
digitCode = digitCode - 'A' + 10;
}
else
{
break;
}
se.Pop();
code = code * 16 + digitCode;
}
return((char)code);
}
private static Renderer ParseRenderer(StringEnumerator se)
{
var character = se.Pop();
var name = ParseRendererName(se);
var renderer = CreateRendererInstance(name);
character = se.Pop();
while (character != -1 && character != '}')
{
var parameterName = ParseParameterName(se).Trim();
if (se.Peek() == '=')
{
// Skip the `=`
se.Pop();
var parameterValue = ParseParameterValue(se);
SetPropertyValue(renderer, parameterName, parameterValue);
}
character = se.Pop();
}
return(renderer);
}
private static string ParseParameterName(StringEnumerator se)
{
var parameterName = new StringBuilder();
int character;
int nestLevel = 0;
while ((character = se.Peek()) != -1)
{
if ((character == '=' || character == '}' || character == ':') && nestLevel == 0)
{
break;
}
switch (character)
{
case '$':
se.Pop();
parameterName.Append('$');
if (se.Peek() == '{')
{
parameterName.Append('{');
nestLevel++;
se.Pop();
}
continue;
case '}':
nestLevel--;
break;
case '\\':
// Skip the backslash
se.Pop();
// Append next character
parameterName.Append((char)se.Pop());
continue;
}
parameterName.Append((char)character);
se.Pop();
}
return(parameterName.ToString());
}
private static string ParseRendererName(StringEnumerator se)
{
var name = new StringBuilder();
int character;
while ((character = se.Peek()) != -1)
{
if (character == ':' || character == '}')
{
break;
}
name.Append((char)character);
se.Pop();
}
return(name.ToString());
}
public static List <Renderer> CompileRenderers(StringEnumerator se, bool isNested, out string text)
{
var renderers = new List <Renderer>();
var literal = new StringBuilder();
int character;
int startPosition = se.Position;
while ((character = se.Peek()) != -1)
{
if (isNested)
{
// Possible escape char `\`
if (character == '\\')
{
se.Pop();
var nextChar = se.Peek();
// Escape chars
if (IsEndOfRenderer(nextChar))
{
// Read next char and append
se.Pop();
literal.Append((char)nextChar);
}
else
{
// Don't treat `\` as escape char
literal.Append('\\');
}
continue;
}
if (IsEndOfRenderer(character))
{
// End of inner renderer.
// `}` is when double nested inner renderer.
// `:` when single nested renderer
break;
}
}
se.Pop();
// Detect `${` (indicates a new renderer)
if (character == '$' && se.Peek() == '{')
{
AddLiteral(literal, renderers);
var newRenderer = ParseRenderer(se);
if (CanBeConvertedToLiteral(newRenderer))
{
newRenderer = ConvertToLiteral(newRenderer);
}
renderers.Add(newRenderer);
}
else
{
literal.Append((char)character);
}
}
AddLiteral(literal, renderers);
var endPosition = se.Position;
MergeLiterals(renderers);
text = se.Substring(startPosition, endPosition);
return(renderers);
}
private static string ParseParameterValue(StringEnumerator se)
{
var value = new StringBuilder();
int character;
while ((character = se.Peek()) != -1)
{
if (character == ':' || character == '}')
{
break;
}
// Code in this condition was replaced
// to support escape codes e.g. '\r' '\n' '\u003a',
// which can not be used directly as they are used as tokens by the parser
// All escape codes listed in the following link were included
// in addition to "\{", "\}", "\:" which are NLog specific:
// http://blogs.msdn.com/b/csharpfaq/archive/2004/03/12/what-character-escape-sequences-are-available.aspx
if (character == '\\')
{
// Skip the backslash
se.Pop();
var nextChar = (char)se.Peek();
switch (nextChar)
{
case ':':
case '{':
case '}':
case '\'':
case '"':
case '\\':
se.Pop();
value.Append(nextChar);
break;
case '0':
se.Pop();
value.Append('\0');
break;
case 'a':
se.Pop();
value.Append('\a');
break;
case 'b':
se.Pop();
value.Append('\b');
break;
case 'f':
se.Pop();
value.Append('\f');
break;
case 'n':
se.Pop();
value.Append('\n');
break;
case 'r':
se.Pop();
value.Append('\r');
break;
case 't':
se.Pop();
value.Append('\t');
break;
case 'u':
se.Pop();
value.Append(GetUnicode(se, 4)); // 4 digits
break;
case 'U':
se.Pop();
value.Append(GetUnicode(se, 8)); // 8 digits
break;
case 'x':
se.Pop();
value.Append(GetUnicode(se, 4)); // 1-4 digits
break;
case 'v':
se.Pop();
value.Append('\v');
break;
}
continue;
}
value.Append((char)character);
se.Pop();
}
return(value.ToString());
}
