On Saturday, 12 December 2020 at 16:43:43 UTC, Bastiaan Veelo
wrote:
On Friday, 11 December 2020 at 19:49:12 UTC, vnr wrote:
For a project with good performance, I would need to be able
to analyse text. To do so, I would write a parser by hand
using the recursive descent algorithm, based on a stream of
tokens. I started writing a lexer with the d-lex package
(https://code.dlang.org/packages/d-lex), it works really well,
unfortunately, it's quite slow for the number of lines I'm
aiming to analyse (I did a test, for a million lines, it
lasted about 3 minutes). As the parser will only have to
manipulate tokens, I think that the performance of the lexer
will be more important to consider. Therefore, I wonder what
resources there are, in D, for writing an efficient lexer.
Have you looked at Pegged [1]? It will give you the lexer and
parser in one go. I'd be very interested to see how it performs
on that kind of input.
-- Bastiaan.
[1] https://code.dlang.org/packages/pegged
Yes, I know Pegged, it's a really interesting parser generator
engine, nevertheless, the grammar of what I would like to analyse
is not a PEG. But I am also curious to know the performances of
this tool for very large inputs.
