Thun/thun/gnu-prolog/meta-defs.pl

41 lines
920 B
Prolog

/*
Definitions
*/
do :- assert_defs(`defs.txt`), print_defs, halt.
joy_def(def(Def, Body)) --> symbol(Def), blanks, "==", joy_parse(Body).
joy_defs --> blanks, joy_def(Def), {assert_def(Def)}, blanks, joy_defs.
joy_defs --> [].
assert_defs(DefsFile) :-
read_file_to_codes(DefsFile, Codes, []),
phrase(joy_defs, Codes).
assert_def(def(Def, Body)) :-
retractall(def(Def, _)),
assertz(def(Def, Body)).
read_file_to_codes(File, Codes, _) :-
open(File, read, Stream),
stream_to_codes(Stream, Codes),
close(Stream).
stream_to_codes(Stream, Codes) :-
get_code(Stream, Code),
stream_to_codes(Code, Stream, Codes).
stream_to_codes(-1, _, []) :- !.
stream_to_codes(Ch, Stream, [Ch|Codes]) :- stream_to_codes(Stream, Codes).
print_defs :-
findall(def(Name, Body), def(Name, Body), List),
maplist(print_def, List).
print_def(Def) :- write(Def), write(`.`), nl.