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Better string_get_n_chars_/3

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bakaq
2023-09-24 19:21:03 -03:00
parent 2fe79b5fc3
commit c50291cec8
1 changed files with 9 additions and 37 deletions
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46
src/lib/pio.pl
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@@ -22,7 +22,7 @@
:- use_module(library(iso_ext), [ :- use_module(library(iso_ext), [
bb_get/2, bb_put/2, setup_call_cleanup/3, partial_string/3, partial_string_tail/2 bb_get/2, bb_put/2, setup_call_cleanup/3, partial_string/3, partial_string_tail/2
]). ]).
:- use_module(library(lists), [length/2, member/2, maplist/2]). :- use_module(library(lists), [append/3, length/2, member/2, maplist/2]).
:- use_module(library(charsio), [get_n_chars/3]). :- use_module(library(charsio), [get_n_chars/3]).
:- meta_predicate(phrase_from_file(2, ?)). :- meta_predicate(phrase_from_file(2, ?)).
@@ -71,39 +71,18 @@ phrase_from_file(NT, File, Options) :-
% How many chars to read from stream and buffer in each step % How many chars to read from stream and buffer in each step
chars_to_read(4096). chars_to_read(4096).
stream_to_lazy_list(Stream, Xs) :- stream_to_lazy_list(Stream, Ls) :-
stream_property(Stream, reposition(Rep)),
( Rep = true ->
stream_to_lazy_list_repositionable(Stream, Xs)
; stream_to_lazy_list_buffer(Stream, Xs)
).
stream_to_lazy_list_repositionable(Stream, Xs) :-
stream_property(Stream, position(Pos)),
freeze(Xs, reader_step_repositionable(Stream, Pos, Xs)).
reader_step_repositionable(Stream, Pos, Xs0) :-
set_stream_position(Stream, Pos),
( at_end_of_stream(Stream)
-> Xs0 = []
; chars_to_read(CharsToRead),
get_n_chars(Stream, CharsToRead, Cs),
partial_string(Cs, Xs0, Xs),
stream_to_lazy_list_repositionable(Stream, Xs)
).
stream_to_lazy_list_buffer(Stream, Ls) :-
get_stream_buffer_position(Stream, Pos), get_stream_buffer_position(Stream, Pos),
freeze(Ls, render_step_buffer(Stream, Pos, Ls)). freeze(Ls, render_step(Stream, Pos, Ls)).
render_step_buffer(Stream, Pos, Ls) :- render_step(Stream, Pos, Ls) :-
set_stream_buffer_position(Stream, Pos), set_stream_buffer_position(Stream, Pos),
( buffer_at_end_of_stream(Stream) -> ( buffer_at_end_of_stream(Stream) ->
Ls = [] Ls = []
; chars_to_read(CharsToRead), ; chars_to_read(CharsToRead),
buffer_get_n_chars(Stream, CharsToRead, Chars), buffer_get_n_chars(Stream, CharsToRead, Chars),
partial_string(Chars, Ls, Ls0), partial_string(Chars, Ls, Ls0),
stream_to_lazy_list_buffer(Stream, Ls0) stream_to_lazy_list(Stream, Ls1)
). ).
buffer_at_end_of_stream(Stream) :- buffer_at_end_of_stream(Stream) :-
@@ -173,17 +152,10 @@ string_get_n_chars(String, Pos, N, Chars) :-
'$skip_max_list'(_, Pos, String, String1), '$skip_max_list'(_, Pos, String, String1),
string_get_n_chars_(String1, N, Chars). string_get_n_chars_(String1, N, Chars).
string_get_n_chars_([], _, []). string_get_n_chars_(String, N, Chars) :-
string_get_n_chars_([S|Ss], N, Chars) :- '$skip_max_list'(N1, N, String, _),
( N = 0 -> length(Chars, N1),
Chars = [] append(Chars, _, String).
; N = 1 ->
% This case is needed to not break the tail of the partial string
Chars = [S]
; Chars = [S|Cs],
N1 is N - 1,
string_get_n_chars_(Ss, N1, Cs)
).
stream_bufferids(Stream, BufferId, BufferPosId, BufferLenId) :- stream_bufferids(Stream, BufferId, BufferPosId, BufferLenId) :-
( bb_get(streams_buffers, _) -> ( bb_get(streams_buffers, _) ->