std::pair<Integer, bool> eatInteger(void)
{
auto res = eatNumber();
if (!res.second)
{
// make sure it is 0
return std::make_pair(static_cast<Integer>(0), false);
}
return std::make_pair(static_cast<Integer>(res.first), true);
}
/* The lexer is in charge of reading the file.
* Some of sub-lexer (like eatComment) also read file.
* lexing is finished when the lexer return Tok_EOF */
static ocamlKeyword lex (lexingState * st)
{
int retType;
/* handling data input here */
while (st->cp == NULL || st->cp[0] == '\0')
{
st->cp = fileReadLine ();
if (st->cp == NULL)
return Tok_EOF;
}
if (isAlpha (*st->cp))
{
readIdentifier (st);
retType = lookupKeyword (vStringValue (st->name), Lang_Ocaml);
if (retType == -1) /* If it's not a keyword */
{
return OcaIDENTIFIER;
}
else
{
return retType;
}
}
else if (isNum (*st->cp))
return eatNumber (st);
else if (isSpace (*st->cp))
{
eatWhiteSpace (st);
return lex (st);
}
/* OCaml permit the definition of our own operators
* so here we check all the consecuting chars which
* are operators to discard them. */
else if (isOperator[*st->cp])
return eatOperator (st);
else
switch (*st->cp)
{
case '(':
if (st->cp[1] == '*') /* ergl, a comment */
{
eatComment (st);
return lex (st);
}
else
{
st->cp++;
return Tok_PARL;
}
case ')':
st->cp++;
return Tok_PARR;
case '[':
st->cp++;
return Tok_BRL;
case ']':
st->cp++;
return Tok_BRR;
case '{':
st->cp++;
return Tok_CurlL;
case '}':
st->cp++;
return Tok_CurlR;
case '\'':
st->cp++;
return Tok_Prime;
case ',':
st->cp++;
return Tok_comma;
case '=':
st->cp++;
return Tok_EQ;
case ';':
st->cp++;
return Tok_semi;
case '"':
eatString (st);
return Tok_Val;
case '_':
st->cp++;
return Tok_Val;
case '#':
st->cp++;
return Tok_Sharp;
case '\\':
st->cp++;
return Tok_Backslash;
default:
st->cp++;
break;
}
/* default return if nothing is recognized,
* shouldn't happen, but at least, it will
* be handled without destroying the parsing. */
return Tok_Val;
}
