/usr/share/Yap/cleanup.yap is in yap 6.2.2-6build1.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 | % cleanup.yap
% Copyright (C) 2002 by Christian Thaeter
%
% public interface:
%
% :- fragile name/arity.
% declares the predicate denoted by name/arity as fragile predicate.
% Whenever such a fragile predicate is used in a query it will be
% called through call_cleanup/1.
%
% call_cleanup(Goal).
% call_cleanup(Goal,CleanUpGoal).
% Goal will be called in a cleanup-context, where any registered
% CleanUpGoal inside of that context will be called when Goal is left,
% either by a fail, cut or exeption.
% It is possible to nest cleanup contexts.
%
% on_cleanup(CleanUpGoal).
% registers CleanUpGoal to the current cleanup context.
% CleanUpGoal's are executed in reverse order of their registration.
% throws an exception if called outside of any cleanup-context.
%
% cleanup_all.
% calls all pending CleanUpGoals and resets the cleanup-system to an initial state.
% should only be used as one of the last calls in the main program.
%
% hidden predicates:
% most private predicates could also be used in special cases, such as manually setting up cleanup-contexts.
% Read the Source.
:- module( cleanup, [
call_cleanup/2,
call_cleanup/1,
on_cleanup/1,
cleanup_all/0,
op(1150, fx,fragile)
]).
:- multifile user:goal_expansion/3.
:- user_defined_directive(fragile(G), cleanup:cleanup_expansion(G)).
:- meta_predicate
call_cleanup(:,:),
call_cleanup(:),
on_cleanup(:),
on_cleanup(?,:),
on_cleanupz(:),
on_cleanupz(?,:).
:- initialization(init_cleanup).
init_cleanup :-
bb_put(expansion_toggle,1),
\+ bb_get(cleanup_level,_),
bb_put(cleanup_level,0).
% TODO: would be nice to register cleanup_all into the
% toplevel to be called after each query is finished
init_cleanup.
% call goal G with a cleanup CL in a cleanup context
call_cleanup(G,CL) :-
needs_cleanup(L),
on_cleanup(L,CL),
(
catch(G,X,(do_cleanup(L),throw(X)))
;
do_cleanup(L)
).
% call a goal G in a cleanup context
call_cleanup(G) :-
needs_cleanup(L),
(
catch(G,X,(do_cleanup(L),throw(X)))
;
do_cleanup(L)
).
% begin cleanup level
needs_cleanup(CL) :-
bb_get(cleanup_level,L),
CL is L + 1,
bb_put(cleanup_level,CL).
cleanup_context(CL) :-
bb_get(cleanup_level,CL).
% leave cleanup level, call all registred cleanup predicates within
do_cleanup(CL) :-
CN is CL - 1,
bb_put(cleanup_level,CN),
next_cleanup(CL).
next_cleanup(CL) :-
!,recorded(cleanup:handle,(L,G),R),
CL =< L,
erase(R),
(call(G);true),
next_cleanup(CL).
% clean up all remaining stuff / reinitialize cleanup-module
cleanup_all :-
do_cleanup(1).
cleanup_all.
% register a cleanup predicate (normal reverse-order cleanup)
on_cleanup(G) :-
bb_get(cleanup_level,L),
on_cleanup(L,G).
on_cleanup(L,G) :-
L =< 0,
throw(error(instantiation_error,no_cleanup_context(G))).
on_cleanup(L,G) :-
callable(G),
recorda(cleanup:handle,(L,G),_).
% register a cleanup predicate (reverse-reverse-order cleanup)
on_cleanupz(G) :-
bb_get(cleanup_level,L),
on_cleanupz(L,G).
on_cleanupz(L,G) :-
L =< 0,
throw(no_cleanup_context(G)).
on_cleanupz(L,G) :-
callable(G),
recordz(cleanup:handle,(L,G),_).
% helpers
cleanup_expansion(X) :-
var(X),!,throw(error(instantiation_error,fragile(X))).
cleanup_expansion((H,T)) :- !,cleanup_expansion(H),cleanup_expansion(T).
cleanup_expansion([H,T]) :- !, cleanup_expansion(H),
( T = [] -> true ; cleanup_expansion(T) ).
cleanup_expansion(M:G/A) :-
atom(G),integer(A),!,
compose_var_goal(G/A,GG),
\+ user:goal_expansion(GG,M,call_cleanup(M:GG)),
assert(( user:goal_expansion(GG,M,NG)
:- bb_get(expansion_toggle,1)
-> bb_put(expansion_toggle,0),
NG=call_cleanup(M:GG)
; bb_put(expansion_toggle,1),
NG=M:GG )).
cleanup_expansion(G/A) :-
!,prolog_flag(typein_module,M),cleanup_expansion(M:G/A).
cleanup_expansion(X) :-
!,throw(error(instantiation_error,fragile(X))).
compose_var_goal(G/A,NG) :-
arity_to_vars(A,L), NG =.. [G|L].
arity_to_vars(N,L) :-
arity_to_vars(N,[],L).
arity_to_vars(N,L1,L2) :-
N > 0,
NN is N-1,
LT = [L|L1],
arity_to_vars(NN,LT,L2).
arity_to_vars(0,L,L).
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