public TemplateParserEnumerator(string text)
{
_text = text;
_start = 0;
_end = 0;
_type = default;
}
public SyntaxElement(SyntaxElementType type, string text, Range range)
{
Type = type;
Text = text;
Range = range;
}
public bool MoveNext()
{
var text = _text;
_start = _end;
if (text.Length <= _start)
{
return(false);
}
var i = _start;
var first = text[i];
_type = SyntaxElementType.Invalid;
if (first == '$')
{
++i;
if (i < text.Length)
{
var second = text[i];
if (second == '(') // $(expression)
{
var bracketNest = 0;
for (++i; i < text.Length; ++i)
{
var c = text[i];
if (c == '(')
{
++bracketNest;
}
else if (c == ')')
{
--bracketNest;
if (bracketNest < 0)
{
++i;
_type = SyntaxElementType.Expression;
break;
}
}
}
}
else if (second == '<') // $< any raw codes $>
{
for (++i; i < text.Length; ++i)
{
var c = text[i];
if (c == '$')
{
++i;
if (i < text.Length && text[i] == '>')
{
++i;
_type = SyntaxElementType.Raw;
break;
}
}
}
}
else // identifier or keywords
{
// $if, $for, $foreach, $while
var keyword =
StartWith(text.AsSpan(i), "if") ? 2 :
StartWith(text.AsSpan(i), "for") ? 3 :
StartWith(text.AsSpan(i), "foreach") ? 7 :
StartWith(text.AsSpan(i), "while") ? 5 :
0;
if (keyword != 0)
{
i += keyword;
_type = SyntaxElementType.ControlStart;
for (++i; i < text.Length; ++i)
{
if (text[i] == '$')
{
++i;
if (i < text.Length && text[i] == '{')
{
++i;
break;
}
}
}
}
else if (CharHelper.IsIdentifierStart(text[i]))
{
// $identifier
_type = SyntaxElementType.Identifier;
for (++i; i < text.Length; ++i)
{
if (!CharHelper.IsIdentifierPart(text[i]))
{
break;
}
}
}
}
}
}
else if (first == '\\') // ignore characters until \n (including \n)
{
for (++i; i < text.Length; ++i)
{
if (text[i] == '\n')
{
++i;
_type = SyntaxElementType.EndOfLine;
break;
}
}
}
else // string
{
_type = SyntaxElementType.String;
for (++i; i < text.Length; ++i)
{
var c = text[i];
if (c == '$')
{
break;
}
if (c == '\\')
{
var j = i + 1;
if (j < text.Length)
{
var c1 = text[j];
if (c1 == '\r' || c1 == '\n')
{
break;
}
}
}
}
}
_end = i;
return(true);
}
