void ReadNumber(SourceUnit unit, ScanResult <LoreToken> result)
{
const string HexChars = "abcdefABCDEF";
var accum = new StringBuilder();
var isfloat = false;
var nofloatstart = false;
var nofloatend = false;
var ishex = false;
var chr = unit.Peek();
if (chr == '.')
{
nofloatstart = true;
accum.Append("0");
}
else if (chr == '0' && unit.See(2) && unit.Peek(1) == 'x')
{
ishex = true;
unit.Skip(2);
}
if (!unit.See(0))
{
Throw("Unexpected end of file.");
}
while (unit.See(0) && (chr = unit.Peek()) > 0)
{
if (chr == '.')
{
if (!unit.See(1) || !char.IsDigit(unit.Peek(1)))
{
nofloatend = true;
if (nofloatstart)
{
Throw("Floating-point literal must have a digit before or after the decimal point.");
}
}
if (isfloat)
{
break;
// Throw ("There can only be one decimal point in a floating-point literal.");
}
isfloat = true;
accum.Append(unit.Read());
if (nofloatend)
{
accum.Append('0');
break;
}
continue;
}
if (ishex)
{
if (char.IsDigit(chr) || HexChars.Contains(chr))
{
accum.Append(unit.Read());
continue;
}
break;
}
if (char.IsDigit(chr))
{
accum.Append(unit.Read());
continue;
}
break;
}
var str = accum.ToString();
ulong hexvalue = 0;
if (ishex)
{
if (!ulong.TryParse(str, NumberStyles.HexNumber, NumberFormatInfo.InvariantInfo, out hexvalue))
{
try {
ulong.Parse(str, NumberStyles.HexNumber, NumberFormatInfo.InvariantInfo);
} catch (Exception e) {
Throw($"Unable to parse base-16 integer literal: {e.Message}.");
}
}
}
else if (isfloat)
{
try {
float.Parse(str, NumberStyles.Float, NumberFormatInfo.InvariantInfo);
} catch (Exception e) {
Throw($"Unable to parse floating-point literal: {e.Message}.");
}
}
else
{
try {
ulong.Parse(str, NumberStyles.Integer, NumberFormatInfo.InvariantInfo);
} catch (Exception e) {
Throw($"Unable to parse integer literal: {e.Message}.");
}
}
result.Token = isfloat ? LoreToken.FloatLiteral : LoreToken.IntLiteral;
result.Value = ishex ? hexvalue.ToString() : str;
}
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++;
}
}