private static void Output(ColoredCharacter[] result, ref int index, string value, ConsoleColor color)
{
for (var i = 0; i < value.Length; i++, index++)
{
result[index] = new ColoredCharacter(value[i], color);
}
}
public ColoredCharacter[] Highlight(string line)
{
var index = 0;
var result = new ColoredCharacter[line.Length];
while (index < line.Length)
{
switch (_state)
{
case TokenState.None:
ColorNone(line, result, ref index);
break;
case TokenState.MultiComment:
ColorMultiComment(line, result, ref index);
break;
case TokenState.String:
ColorString(line, result, ref index);
break;
}
}
return(result);
}
private void ColorMultiComment(string line, ColoredCharacter[] result, ref int index)
{
while (_multiCommentDepth > 0)
{
if (index >= line.Length)
{
return;
}
if (OutputIfNext(line, result, ref index, "/*", CommentColor))
{
_multiCommentDepth++;
continue;
}
if (OutputIfNext(line, result, ref index, "*/", CommentColor))
{
_multiCommentDepth--;
continue;
}
result[index] = new ColoredCharacter(line[index], CommentColor);
index++;
}
_state = TokenState.None;
}
private void ColorString(string line, ColoredCharacter[] result, ref int index)
{
while (index < line.Length)
{
var ch = line[index];
if (ch == '\\' && index + 1 < line.Length && line[index + 1] == _stringTerminator)
{
result[index + 0] = new ColoredCharacter('\\', StringColor);
result[index + 1] = new ColoredCharacter(_stringTerminator, StringColor);
index += 2;
continue;
}
result[index] = new ColoredCharacter(ch, StringColor);
index++;
if (ch == _stringTerminator)
{
_state = TokenState.None;
_stringTerminator = '\0';
return;
}
}
}
public ColoredCharacter[] Highlight(string line)
{
var index = 0;
var result = new ColoredCharacter[line.Length];
while (index < line.Length)
{
switch (_state)
{
case TokenState.None:
ColorNone(line, result, ref index);
break;
case TokenState.MultiComment:
ColorMultiComment(line, result, ref index);
break;
case TokenState.String:
ColorString(line, result, ref index);
break;
}
}
return result;
}
private void ColorNone(string line, ColoredCharacter[] result, ref int index)
{
while (index < line.Length)
{
if (OutputIfNext(line, result, ref index, "//", CommentColor))
{
for (var i = index; i < line.Length; i++, index++)
{
result[i] = new ColoredCharacter(line[i], CommentColor);
}
return;
}
if (OutputIfNext(line, result, ref index, "/*", CommentColor))
{
_state = TokenState.MultiComment;
_multiCommentDepth = 1;
return;
}
var ch = line[index];
if (OutputIfNext(line, result, ref index, "\"", StringColor) ||
OutputIfNext(line, result, ref index, "\'", StringColor))
{
_state = TokenState.String;
_stringTerminator = ch;
return;
}
if (Operators.TryGetValue(ch, out var operators))
{
var idx = index;
var op = operators.FirstOrDefault(s => IsNext(line, idx, s));
if (op != null)
{
Output(result, ref index, op, OperatorColor);
continue;
}
}
if (char.IsLetter(ch) || ch == '_' || ch == '`')
{
var start = index;
var isBacktick = ch == '`';
if (isBacktick)
{
index++; // opening backtick
}
while (index < line.Length && (char.IsLetterOrDigit(line[index]) || line[index] == '_'))
{
index++;
}
if (isBacktick && index < line.Length && line[index] == '`')
{
index++; // closing backtick
}
var word = line.Substring(start, index - start);
index = start;
if (isBacktick)
{
Output(result, ref index, word, OperatorColor);
continue;
}
if (Keywords.Contains(word))
{
Output(result, ref index, word, KeywordColor);
continue;
}
Output(result, ref index, word, IdentifierColor);
continue;
}
if (char.IsDigit(ch))
{
var format = NumberFormat.Decimal;
var hasDecimal = false;
var hasExp = false;
var justTake = false;
if (ch == '0' && index + 1 < line.Length)
{
var nextChar = line[index + 1];
if (nextChar == 'x' || nextChar == 'X')
{
format = NumberFormat.Hexadecimal;
}
if (nextChar == 'b' || nextChar == 'B')
{
format = NumberFormat.Binary;
}
if (format != NumberFormat.Decimal)
{
if (index + 2 < line.Length && line[index + 2] == '_')
{
result[index++] = new ColoredCharacter('0', NumberColor);
continue;
}
result[index + 0] = new ColoredCharacter('0', NumberColor);
result[index + 1] = new ColoredCharacter(nextChar, NumberColor);
index += 2;
}
}
bool IsDigit(char c) =>
char.IsDigit(c) || (format == NumberFormat.Hexadecimal && HexChars.Contains(c));
while (index < line.Length)
{
var c = line[index];
if (justTake)
{
justTake = false;
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
if (c == '_' && (index + 1 < line.Length && IsDigit(line[index + 1])))
{
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
if (format == NumberFormat.Decimal)
{
if (c == '.' && !hasDecimal && !hasExp)
{
hasDecimal = true;
if (index + 1 >= line.Length || !IsDigit(line[index + 1]))
{
break;
}
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
if ((c == 'e' || c == 'E') && !hasExp)
{
if (index + 1 < line.Length)
{
var next = line[index + 1];
if (next == '+' || next == '-')
{
justTake = true;
}
}
hasExp = true;
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
}
if (!IsDigit(c))
{
break;
}
result[index++] = new ColoredCharacter(c, NumberColor);
}
continue;
}
result[index] = new ColoredCharacter(line[index], OtherColor);
index++;
}
}
private static Highlighter Redraw()
{
var inputString = new string(_input.ToArray());
var newHighlighter = _originalHighlighter.Clone();
var currentColors = newHighlighter.Highlight(inputString);
SavePosition();
var length = Math.Max(currentColors.Length, _previousColors.Length);
int start = 0;
for (; start < length; start++)
{
if (start >= _previousColors.Length || start >= currentColors.Length)
{
break;
}
var prev = _previousColors[start];
var curr = currentColors[start];
if (prev.Character != curr.Character || prev.Color != curr.Color)
{
break;
}
}
Move(-_position + start);
ConsoleColor?prevColor = null;
for (var i = start; i < length; i++)
{
var curr = new ColoredCharacter(' ', ConsoleColor.Gray);
if (i < currentColors.Length)
{
curr = currentColors[i];
}
if (!prevColor.HasValue || prevColor.Value != curr.Color)
{
Console.ForegroundColor = curr.Color;
}
prevColor = curr.Color;
Console.Write(curr.Character);
_position++;
if (Console.CursorLeft == Console.BufferWidth - 1 && Console.CursorTop == Console.BufferHeight - 1)
{
Console.WriteLine();
Move(-1);
_position++;
}
}
RestorePosition();
_previousColors = currentColors;
return(newHighlighter);
}
private void ColorString(string line, ColoredCharacter[] result, ref int index)
{
while (index < line.Length)
{
var ch = line[index];
if (ch == '\\' && index + 1 < line.Length && line[index + 1] == _stringTerminator)
{
result[index + 0] = new ColoredCharacter('\\', StringColor);
result[index + 1] = new ColoredCharacter(_stringTerminator, StringColor);
index += 2;
continue;
}
result[index] = new ColoredCharacter(ch, StringColor);
index++;
if (ch == _stringTerminator)
{
_state = TokenState.None;
_stringTerminator = '\0';
return;
}
}
}
private void ColorNone(string line, ColoredCharacter[] result, ref int index)
{
while (index < line.Length)
{
if (OutputIfNext(line, result, ref index, "//", CommentColor))
{
for (var i = index; i < line.Length; i++, index++)
{
result[i] = new ColoredCharacter(line[i], CommentColor);
}
return;
}
if (OutputIfNext(line, result, ref index, "/*", CommentColor))
{
_state = TokenState.MultiComment;
_multiCommentDepth = 1;
return;
}
var ch = line[index];
if (OutputIfNext(line, result, ref index, "\"", StringColor) ||
OutputIfNext(line, result, ref index, "\'", StringColor))
{
_state = TokenState.String;
_stringTerminator = ch;
return;
}
string[] operators;
if (Operators.TryGetValue(ch, out operators))
{
var idx = index;
var op = operators.FirstOrDefault(s => IsNext(line, idx, s));
if (op != null)
{
Output(result, ref index, op, OperatorColor);
continue;
}
}
if (char.IsLetter(ch) || ch == '_')
{
var start = index;
while (index < line.Length && (char.IsLetterOrDigit(line[index]) || line[index] == '_'))
{
index++;
}
var word = line.Substring(start, index - start);
index = start;
if (Keywords.Contains(word))
{
Output(result, ref index, word, KeywordColor);
continue;
}
Output(result, ref index, word, IdentifierColor);
continue;
}
if (char.IsDigit(ch))
{
var format = NumberFormat.Decimal;
var hasDecimal = false;
var hasExp = false;
var justTake = false;
if (ch == '0' && index + 1 < line.Length)
{
var nextChar = line[index + 1];
if (nextChar == 'x' || nextChar == 'X')
format = NumberFormat.Hexadecimal;
if (nextChar == 'b' || nextChar == 'B')
format = NumberFormat.Binary;
if (format != NumberFormat.Decimal)
{
if (index + 2 < line.Length && line[index + 2] == '_')
{
result[index++] = new ColoredCharacter('0', NumberColor);
continue;
}
result[index + 0] = new ColoredCharacter('0', NumberColor);
result[index + 1] = new ColoredCharacter(nextChar, NumberColor);
index += 2;
}
}
Func<char, bool> isDigit = c => char.IsDigit(c) || (format == NumberFormat.Hexadecimal && HexChars.Contains(c));
while (index < line.Length)
{
var c = line[index];
if (justTake)
{
justTake = false;
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
if (c == '_' && (index + 1 < line.Length && isDigit(line[index + 1])))
{
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
if (format == NumberFormat.Decimal)
{
if (c == '.' && !hasDecimal && !hasExp)
{
hasDecimal = true;
if (index + 1 >= line.Length || !isDigit(line[index + 1]))
break;
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
if ((c == 'e' || c == 'E') && !hasExp)
{
if (index + 1 < line.Length)
{
var next = line[index + 1];
if (next == '+' || next == '-')
justTake = true;
}
hasExp = true;
result[index++] = new ColoredCharacter(c, NumberColor);
continue;
}
}
if (!isDigit(c))
break;
result[index++] = new ColoredCharacter(c, NumberColor);
}
continue;
}
result[index] = new ColoredCharacter(line[index], OtherColor);
index++;
}
}
private void ColorMultiComment(string line, ColoredCharacter[] result, ref int index)
{
while (_multiCommentDepth > 0)
{
if (index >= line.Length)
return;
if (OutputIfNext(line, result, ref index, "/*", CommentColor))
{
_multiCommentDepth++;
continue;
}
if (OutputIfNext(line, result, ref index, "*/", CommentColor))
{
_multiCommentDepth--;
continue;
}
result[index] = new ColoredCharacter(line[index], CommentColor);
index++;
}
_state = TokenState.None;
}
private static bool OutputIfNext(string line, ColoredCharacter[] result, ref int index, string value, ConsoleColor color)
{
var isNext = IsNext(line, index, value);
if (isNext)
Output(result, ref index, value, color);
return isNext;
}
private static void Output(ColoredCharacter[] result, ref int index, string value, ConsoleColor color)
{
for (var i = 0; i < value.Length; i++, index++)
{
result[index] = new ColoredCharacter(value[i], color);
}
}