On 2010-10-26 04:44, Nick Sabalausky wrote:
"Walter Bright"<newshou...@digitalmars.com> wrote in message
news:ia59si$1r0...@digitalmars.com...
Consider a string literal, say "abc\"def". With Goldie's method, I infer
this string has to be scanned twice. Once to find its limits, and the
second to convert it to the actual string.
Yea, that is true. With that string in the input, the value given to the
user code will be:
assert(tokenObtainedFromGoldie.toString() == q{"abc\"def"});
That's a consequence of the grammar being separated from lexing/parsing
implementation.
You're right that that does seem less than ideal. Although I'm not sure how
to remedy that without loosing the independence between grammar and
lex/parse implementation that is the main point of the GOLD-based style.
But there's something I don't quite understand about the approach you're
suggesting: You seem to be suggesting that a terminal be progressively
converted into its final form *as* it's still in the process of being
recognized by the DFA. Which means, you don't know *what* you're supposed to
be converting it into *while* you're converting it.
I don't have much knowledge in this area but isn't this what a
look-ahead is for? Just look ahead (hopefully) one character and decide
what to convert to.
--
/Jacob Carlborg
