// whitespace processing needs to happen in two phases. the first is where we collapse whitespace and handle new lines
// the second is what to do with trailing space and wrapping.
public static int ProcessWhitespace(WhitespaceMode whitespaceMode, ref char[] buffer, char[] input, int inputSize = -1)
{
if (inputSize < 0)
{
inputSize = input.Length;
}
if (inputSize == 0)
{
return(0);
}
bool collapseSpaceAndTab = (whitespaceMode & WhitespaceMode.CollapseWhitespace) != 0;
bool preserveNewLine = (whitespaceMode & WhitespaceMode.PreserveNewLines) != 0;
bool trimStart = (whitespaceMode & WhitespaceMode.TrimStart) != 0;
bool trimEnd = (whitespaceMode & WhitespaceMode.TrimEnd) != 0;
bool collapsing = false;
if (buffer == null)
{
buffer = ArrayPool <char> .GetMinSize(inputSize);
}
if (buffer.Length < inputSize)
{
ArrayPool <char> .Resize(ref buffer, inputSize);
}
int writeIndex = 0;
int start = 0;
int end = inputSize;
if (trimStart)
{
for (int i = 0; i < end; i++)
{
char c = input[i];
bool isWhiteSpace = c == ' ' || c >= '\t' && c <= '\r' || (c == ' ' || c == '\x0085');
if (!isWhiteSpace)
{
start = i;
break;
}
}
}
if (trimEnd)
{
for (int i = end - 1; i >= start; i--)
{
char c = input[i];
bool isWhiteSpace = c == ' ' || c >= '\t' && c <= '\r' || (c == ' ' || c == '\x0085');
if (!isWhiteSpace)
{
end = i + 1;
break;
}
}
}
for (int i = start; i < end; i++)
{
char c = input[i];
if (c == '\n' && !preserveNewLine)
{
continue;
}
bool isWhiteSpace = c == ' ' || c >= '\t' && c <= '\r' || (c == ' ' || c == '\x0085');
if (c == '\n')
{
if (preserveNewLine)
{
buffer[writeIndex++] = c;
continue;
}
}
if (collapsing)
{
if (!isWhiteSpace)
{
buffer[writeIndex++] = c;
collapsing = false;
}
}
else if (isWhiteSpace)
{
collapsing = collapseSpaceAndTab;
buffer[writeIndex++] = ' ';
}
else
{
buffer[writeIndex++] = c;
}
}
return(writeIndex);
}
