From 063b9432cc6db5457b10529cf95f624fdad48d25 Mon Sep 17 00:00:00 2001 From: Markus Triska Date: Thu, 24 Apr 2025 18:19:05 +0200 Subject: [PATCH] ENHANCED: use a fast test for the expected case of chars in atom_chars/2 etc. Suggested by Oleg Finkelstein, thank you a lot! Example, before this change: ?- t+\(length(As, 1_000_000), maplist(=(a), As), time(atom_chars(A, As))). % CPU time: 0.693s, 7_000_041 inferences true. Now: ?- t+\(length(As, 1_000_000), maplist(=(a), As), time(atom_chars(A, As))). % CPU time: 0.080s, 40 inferences true. This also partially ameliorates #2907. --- src/lib/builtins.pl | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/src/lib/builtins.pl b/src/lib/builtins.pl index d553e9b8..8402a89b 100644 --- a/src/lib/builtins.pl +++ b/src/lib/builtins.pl @@ -1719,20 +1719,27 @@ must_be_number(N, PI) :- ). -chars_or_vars(Cs, _) :- +chars_or_vars(Cs, PI) :- + ( '$is_partial_string'(Cs) -> + % use a fast test for the expected case + true + ; chars_or_vars_(Cs, PI) + ). + +chars_or_vars_(Cs, _) :- ( var(Cs) -> ! ; Cs == [] -> ! ). -chars_or_vars([C|Cs], PI) :- +chars_or_vars_([C|Cs], PI) :- ( nonvar(C) -> ( atom(C), atom_length(C, 1) -> chars_or_vars(Cs, PI) ; throw(error(type_error(character, C), PI)) ) - ; chars_or_vars(Cs, PI) + ; chars_or_vars_(Cs, PI) ). -- 2.54.0