protected async IAsyncEnumerable <Token> DoPreprocess(IAsyncStream <Token> input)
{
while (!await input.Eof())
{
Token token;
if ((await input.Peek()).Kind == Pound)
{
await input.Read();
if ((await input.Peek()).Kind == Identifier)
{
switch ((await input.Read() as ValueToken <string>) !.Value.ToLower())
{
protected async IAsyncEnumerable <string> asyncStreamFuncQueries(IAsyncStream <string> input)
{
while (!await input.Eof())
{
yield return((await input.Read()) + "?");
}
}
protected async IAsyncEnumerable <char> CountLines(IAsyncStream <char> input)
{
await foreach (char c in input)
{
yield return(c);
if (c == '\r')
{
if (!await input.Eof() && await input.Peek() == '\n')
{
yield return(await input.Read());
}
TranslationUnit.CurrentLine++;
TranslationUnit.CurrentColumn = 1;
}
else if (c == '\n')
{
TranslationUnit.CurrentLine++;
TranslationUnit.CurrentColumn = 1;
}
else if (c == '\t')
{
// TODO: Is this the expectation for tabs?
TranslationUnit.CurrentColumn += TAB_WIDTH - ((TranslationUnit.CurrentColumn - 1) % TAB_WIDTH);
}
else
{
TranslationUnit.CurrentColumn++;
}
}
}
protected async IAsyncEnumerable <string> asyncStreamFuncLessThan6(IAsyncStream <int> input)
{
while (!await input.Eof())
{
if (await input.Peek() <= 5)
{
yield return((await input.Read()).ToString());
}
else
{
yield break;
}
}
}
protected async Task ProcessIncludeFileLine(IAsyncStream <Token> input, BufferBlock <Token> tokenBuffer)
{
Terminal?t = default;
if ((await input.Peek()).Kind == Pound)
{
var poundToken = (await input.Read());
if ((await input.Peek()).Kind == Identifier)
{
ValueToken <string> directiveToken;
switch ((directiveToken = (ValueToken <string>)(await input.Read())).Value.ToLower())
{
case "include":
if ((t = (await input.Peek()).Kind) == LessThan || t == StringLiteral)
{
string?filename = null;
if (t == StringLiteral)
{
var token = await input.Read();
filename = ((ValueToken <string>)token).Value;
if (!await input.Eof())
{
if ((await input.Peek()).Kind != Newline)
{
// TODO: Error
}
else
{
tokenBuffer.Post(await input.Read());
}
// TODO: Error
}
}
else
{
try
{
var token = await input.Read();
TranslationUnit.LexerState = LexerState.LexingLibraryFilename;
if ((await input.Peek()).Kind == Filename)
{
filename = ((ValueToken <string>) await input.Read()).Value;
}
}
finally
{
TranslationUnit.LexerState = LexerState.LexerReady;
}
if ((await input.Peek()).Kind != GreaterThan)
{
// TODO: Error
}
else
{
await input.Read();
}
if (!await input.Eof())
{
if ((await input.Peek()).Kind != Newline)
{
// TODO: Error
}
else
{
tokenBuffer.Post(await input.Read());
}
// TODO: Error
}
}
if (filename != null)
{
var dummyTask = tokenBuffer.PostAllAsync(
ProcessPipeline(filename, IncludePipeline() !
.Chain(FilterEof !)))
.ContinueWith(_ => tokenBuffer.Complete());
}
}
break;
default:
{
// Pass directive on to the rest of the pipeline
// (this method only handles the #include directive)
tokenBuffer.Post(poundToken);
tokenBuffer.Post(directiveToken);
while (!await input.Eof())
{
var token = await input.Read();
tokenBuffer.Post(token);
if (token.Kind == Newline)
{
break;
}
}
tokenBuffer.Complete();
break;
}
}
}
else
{
// Pass line on to the rest of the pipeline
tokenBuffer.Post(poundToken);
while (!await input.Eof())
{
var token = await input.Read();
tokenBuffer.Post(token);
if (token.Kind == Newline)
{
break;
}
}
tokenBuffer.Complete();
}
}
else
{
while (!await input.Eof())
{
var token = await input.Read();
tokenBuffer.Post(token);
if (token.Kind == Newline)
{
break;
}
}
tokenBuffer.Complete();
}
}
protected async IAsyncEnumerable <char> SpliceLines(IAsyncStream <char> input)
{
char c;
while (!await input.Eof())
{
switch (c = await input.Read())
{
// Splice lines ending in '\' with the next line.
case '\\':
bool whitespace = false;
while (!await input.Eof() && (await input.Peek() == ' ' || await input.Peek() == '\t'))
{
whitespace = true;
await input.Read();
}
if (await input.Eof())
{
if (whitespace)
{
yield return(' ');
}
yield return('\\');
}
else
{
c = await input.Read();
if (c == '\r')
{
if (!await input.Eof() && await input.Peek() == '\n')
{
await input.Read();
}
}
else if (c != '\n')
{
yield return('\\');
if (whitespace)
{
yield return(' ');
}
yield return(c);
}
}
break;
case '\r': // Convert "\r\n" to "\n"
if (!await input.Eof() && await input.Peek() == '\n')
{
await input.Read();
}
yield return('\n');
break;
default:
yield return(c);
break;
}
}
}
protected async IAsyncEnumerable <char> ReplaceTrigraphs(IAsyncStream <char> input)
{
int num_question_marks = 0;
char c;
while (!await input.Eof())
{
switch (c = await input.Read())
{
case '?':
num_question_marks++;
break;
default:
if (num_question_marks >= 2)
{
while (num_question_marks > 2)
{
yield return('?');
num_question_marks--;
}
switch (c)
{
case '=':
yield return('#');
break;
case '/':
yield return('\\');
break;
case '\'':
yield return('^');
break;
case '(':
yield return('[');
break;
case ')':
yield return(']');
break;
case '!':
yield return('|');
break;
case '<':
yield return('{');
break;
case '>':
yield return('}');
break;
case '-':
yield return('~');
break;
default:
while (num_question_marks > 0)
{
yield return('?');
}
yield return(c);
break;
}
num_question_marks = 0;
}
else
{
yield return(c);
}
break;
}
}
while (num_question_marks > 0)
{
yield return('?');
}
}