protected async IAsyncEnumerable <Token> Lex()
{
char c;
while (!await InputStream.Eof())
{
int line = TranslationUnit.CurrentLine, column = TranslationUnit.CurrentColumn;
string filename = TranslationUnit.CurrentFilename;
// #include <FILENAME_TO_PARSE>
if (TranslationUnit.LexerState == LexingLibraryFilename)
{
var sb = new StringBuilder();
while (!await InputStream.Eof() && ((c = await InputStream.Peek()) != '>'))
{
sb.Append(await InputStream.Read());
}
TranslationUnit.LexerState = LexerState.LexerReady;
yield return(new ValueToken <string>(Terminal.Filename, line, column, filename, sb.ToString()));
continue; // Parse the next token
}
c = await InputStream.Read();
if (char.IsLetter(c) || c == '_')
{
var sb = new StringBuilder(c.ToString());
Symbol symbol;
while ((c = await InputStream.Peek()) == '_' || char.IsLetter(c) || char.IsDigit(c))
{
sb.Append(await InputStream.Read());
}
var ident = sb.ToString();
if (ReservedWords.ContainsKey(ident))
{
yield return(new Token(ReservedWords[ident], line, column, filename));
}
else if (TranslationUnit.Symbols.ContainsKey(ident) &&
((symbol = TranslationUnit.Symbols[ident]).Type == SymbolType.EnumSymbol ||
symbol.Type == TypedefSymbol))
{
yield return(symbol.Type == TypedefSymbol
? new ValueToken <Symbol>(TypedefName, line, column, filename, symbol) as Token
: new ValueToken <EnumSymbol>(EnumConstant, line, column, filename, (symbol as EnumSymbol) !) as Token);
}
else
{
yield return(new ValueToken <string>(Identifier, line, column, filename, ident));
}
}
else if (char.IsDigit(c))
{
var integer = 0UL + c - '0';
var fraction = 0M;
var real = 0M;
var hexOrOctal = false;
var floating = false;
var unsigned = false;
var isLong = false;
var nonDouble = false;
var d = 0d;
if (c == '0')
{
if ((c = await InputStream.Peek()) == 'x' || c == 'X')
{
await InputStream.Read();
while (char.IsDigit(c = char.ToLower(await InputStream.Peek())) || (c >= 'a' && c <= 'f'))
{
await InputStream.Read();
integer *= 0x10;
integer += (ulong)(char.IsDigit(c) ? c - '0' : c - 'a' + 0xa);
}
hexOrOctal = true;
}
else if ((c = await InputStream.Peek()) >= '0' && c <= '7') // Octal
{
while ((c = await InputStream.Peek()) >= '0' && c <= '7')
{
c = await InputStream.Read();
integer *= 8;
integer += (ulong)(c - '0');
}
hexOrOctal = true;
}
}
if (!hexOrOctal)
{
while (char.IsDigit(await InputStream.Peek()))
{
c = await InputStream.Read();
integer *= 10;
integer += (ulong)(c - '0');
}
if (await InputStream.Peek() == '.')
{
var multiplier = 0.1M;
floating = true;
await InputStream.Read();
while (char.IsDigit(await InputStream.Peek()))
{
c = await InputStream.Read();
fraction += (c - '0') * multiplier;
multiplier *= 0.1M;
}
d = (double)(integer + fraction);
}
if ((c = await InputStream.Peek()) == 'e' || c == 'E')
{
floating = true;
real = integer + fraction;
var eSign = 1;
var e = 0;
await InputStream.Read();
if ((c = await InputStream.Peek()) == '+' || c == '-')
{
await InputStream.Read();
eSign = c == '-' ? -1 : 1;
}
while (char.IsDigit(await InputStream.Peek()))
{
c = await InputStream.Read();
e *= 10;
e += c - '0';
}
if (real != 0m)
{
e *= eSign;
d = (double)real * Math.Pow(10.0, (double)e);
while (real >= 10m)
{
real /= 10m;
e += eSign;
}
while (real < 1m)
{
real *= 10m;
e -= eSign;
}
if (e == 308 && real >= 1.7976931348623157m || e > 308)
{
d = double.MaxValue;
}
else if (e == -324 && real <= 4.94065645841247m || e < -324)
{
d = double.Epsilon;
}
}
}
}
while ((c = await InputStream.Peek()) == 'l' || c == 'L' || c == 'u' || c == 'U' || c == 'f' || c == 'F')
{
switch (c = char.ToLower(await InputStream.Read()))
{
case 'l':
isLong = true;
break;
case 'u':
unsigned = true;
break;
case 'f':
if (!floating)
{
real = integer;
floating = true;
}
nonDouble = true;
break;
}
}
var valid = true;
if (floating && (isLong || unsigned))
{
Error("Invalid suffix combination");
valid = false;
}
if (floating)
{
var token = new FloatingToken(line, column, filename, d, nonDouble);
token.IsValid = valid;
yield return(token);
}
else
{
yield return(new IntegerToken(line, column, filename, integer, unsigned, isLong));
}
}
else
{
switch (c)
{
case ' ':
case '\t':
while (!await InputStream.Eof() && ((c = await InputStream.Peek()) == ' ' || c == '\t'))
{
await InputStream.Read();
}
if (OutputTrivia)
{
yield return(new Token(Whitespace, line, column, filename));
}
break;
case '\r':
if (await InputStream.Peek() == '\n')
{
await InputStream.Read();
}
if (OutputTrivia)
{
yield return(new Token(Newline, line, column, filename));
}
break;
case '\n':
if (OutputTrivia)
{
yield return(new Token(Newline, line, column, filename));
}
break;
case '\"':
case '\'':
{
char delimeter = c;
var sb = new StringBuilder();
while (!await InputStream.Eof() && (c = await InputStream.Peek()) != delimeter && c != '\r' && c != '\n')
{
if (c == '\\')
{
await InputStream.Read();
if (!await InputStream.Eof())
{
c = await InputStream.Read();
if (char.IsDigit(c) && c < '8')
{
int cc = c - '0';
for (var i = 0; i < 2 && char.IsDigit(c = await InputStream.Peek()) && c < '8'; i++)
{
cc *= 8;
cc += await InputStream.Read() - '0';
}
sb.Append((char)cc);
}
else
{
switch (c)
{
case 'n':
sb.Append('\n');
break;
case 't':
sb.Append('\t');
break;
case 'v':
sb.Append('\v');
break;
case 'b':
sb.Append('\b');
break;
case 'r':
sb.Append('\r');
break;
case 'f':
sb.Append('\f');
break;
case 'a':
sb.Append('\a');
break;
case '\\':
sb.Append('\\');
break;
case '?':
sb.Append('?');
break;
case '\'':
sb.Append('\'');
break;
case '"':
sb.Append('"');
break;
case 'x':
case 'X':
{
var letter = c;
int i;
int cc = 0;
for (i = 0; i < 2 && (char.IsDigit(c = char.ToLower(await InputStream.Peek())) || (c >= 'a' && c <= 'f')); i++)
{
await InputStream.Read();
cc *= 0x10;
if (char.IsDigit(c))
{
cc += c - '0';
}
else
{
cc += char.ToLower(c) - 'a' + 0xa;
}
}
if (i == 0)
{
sb.Append("\\" + letter);
}
else
{
sb.Append((char)cc);
}
break;
}
default:
sb.Append('\\');
sb.Append(c);
break;
}
}
}
}
else
{
sb.Append(await InputStream.Read());
}
}
var valid = true;
if (await InputStream.Eof() || (c = await InputStream.Peek()) != delimeter)
{
Error($"{delimeter} expected");
valid = false;
}
else
{
await InputStream.Read();
}
if (delimeter == '\'' && sb.Length != 1)
{
Error("Invalid character literal");
valid = false;
}
var token = new ValueToken <string>(delimeter == '\"' ? StringLiteral : CharLiteral, line, column, filename, sb.ToString());
token.IsValid = valid;
yield return(token);
break;
}
case '~':
yield return(new Token(Tilde, line, column, filename));
break;
case '#':
if (PreprocessorTokens && await InputStream.Peek() == '#')
{
await InputStream.Read();
yield return(new Token(DoublePound, line, column, filename));
}
else
{
if (!PreprocessorTokens)
{
Error("Unexpected symbol #");
}
yield return(PreprocessorTokens
? new Token(Pound, line, column, filename)
: new ValueToken <char>(Terminal.Unknown, line, column, filename, '#'));
}
break;
case '(':
yield return(new Token(LeftParen, line, column, filename));
break;
case ')':
yield return(new Token(RightParen, line, column, filename));
break;
case '{':
yield return(new Token(LeftBrace, line, column, filename));
break;
case '}':
yield return(new Token(RightBrace, line, column, filename));
break;
case '[':
yield return(new Token(LeftBracket, line, column, filename));
break;
case ']':
yield return(new Token(RightBracket, line, column, filename));
break;
case ':':
yield return(new Token(Colon, line, column, filename));
break;
case ';':
yield return(new Token(Semicolon, line, column, filename));
break;
case ',':
yield return(new Token(Comma, line, column, filename));
break;
case '.':
yield return(new Token(Dot, line, column, filename));
break;
case '?':
yield return(new Token(Query, line, column, filename));
break;
case '!':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(NotEqual, line, column, filename));
}
else
{
yield return(new Token(Bang, line, column, filename));
}
break;
case '%':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(ModAssign, line, column, filename));
}
else
{
yield return(new Token(Percent, line, column, filename));
}
break;
case '^':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(XorAssign, line, column, filename));
}
else
{
yield return(new Token(Caret, line, column, filename));
}
break;
case '&':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(AndAssign, line, column, filename));
}
else if (await InputStream.Peek() == '&')
{
await InputStream.Read();
yield return(new Token(LogicalAnd, line, column, filename));
}
else
{
yield return(new Token(Ampersand, line, column, filename));
}
break;
case '*':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(MultiplyAssign, line, column, filename));
}
else
{
yield return(new Token(Star, line, column, filename));
}
break;
case '-':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(SubtractAssign, line, column, filename));
}
else if (await InputStream.Peek() == '-')
{
await InputStream.Read();
yield return(new Token(Decrement, line, column, filename));
}
else if (await InputStream.Peek() == '>')
{
await InputStream.Read();
yield return(new Token(Arrow, line, column, filename));
}
else
{
yield return(new Token(Minus, line, column, filename));
}
break;
case '+':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(AddAssign, line, column, filename));
}
else if (await InputStream.Peek() == '+')
{
await InputStream.Read();
yield return(new Token(Increment, line, column, filename));
}
else
{
yield return(new Token(Plus, line, column, filename));
}
break;
case '=':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(DoubleEquals, line, column, filename));
}
else
{
yield return(new Token(Assign, line, column, filename));
}
break;
case '|':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(OrAssign, line, column, filename));
}
else if (await InputStream.Peek() == '|')
{
await InputStream.Read();
yield return(new Token(LogicalOr, line, column, filename));
}
else
{
yield return(new Token(Pipe, line, column, filename));
}
break;
case '<':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(LessThanOrEqual, line, column, filename));
}
else if (await InputStream.Peek() == '<')
{
await InputStream.Read();
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(ShiftLeftAssign, line, column, filename));
}
else
{
yield return(new Token(ShiftLeft, line, column, filename));
}
}
else
{
yield return(new Token(LessThan, line, column, filename));
}
break;
case '>':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(GreaterThanOrEqual, line, column, filename));
}
else if (await InputStream.Peek() == '>')
{
await InputStream.Read();
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(ShiftRightAssign, line, column, filename));
}
else
{
yield return(new Token(ShiftRight, line, column, filename));
}
}
else
{
yield return(new Token(GreaterThan, line, column, filename));
}
break;
case '/':
if (await InputStream.Peek() == '=')
{
await InputStream.Read();
yield return(new Token(DivideAssign, line, column, filename));
}
else if (await InputStream.Peek() == '/')
{
await InputStream.Read();
var sb = OutputTrivia ? new StringBuilder() : null;
while (!await InputStream.Eof() && await InputStream.Peek() != '\r' && await InputStream.Peek() != '\n')
{
c = await InputStream.Read();
if (OutputTrivia)
{
sb !.Append(c);
}
}
if (OutputTrivia)
{
yield return(new ValueToken <string>(Comment, line, column, filename, sb !.ToString().Trim()));
}
}
else if (await InputStream.Peek() == '*')
{
await InputStream.Read();
var sb = OutputTrivia ? new StringBuilder() : null;
var terminated = false;
while (!await InputStream.Eof())
{
if (await InputStream.Peek() == '*')
{
await InputStream.Read();
if (await InputStream.Peek() == '/')
{
await InputStream.Read();
terminated = true;
break;
}
else if (OutputTrivia)
{
sb !.Append('*');
}
}
else
{
c = await InputStream.Read();
if (OutputTrivia)
{
sb !.Append(c);
}
}
}
if (!terminated)
{
Error("Unterminated comment.");
}
if (OutputTrivia)
{
var token = new ValueToken <string>(Comment, line, column, filename, sb !.ToString().Trim());
if (!terminated)
{
token.IsValid = false;
}
yield return(token);
}
}
else
{
yield return(new Token(Slash, line, column, filename));
}
break;
default:
yield return(new ValueToken <char>(Terminal.Unknown, line, column, filename, c));
Error($"Unexpected symbol {c}");
break;
}
}
}
yield return(Sentinel);
}
