mirror of
https://github.com/Mercury-Language/mercury.git
synced 2025-12-20 00:15:27 +00:00
81175cbf10
bintree_set.nl: Fix naming conventions (delete/remove). (XXX should fix set.nl too!) graph.nl, pqueue.nl, random.nl, bintree_set.nl: Add missing determinism annotations. io.nl, io.nu.nl: Add io__call_system. mercury_compile.nl: Call a script `mercury_update_interface' to update the interface files without stuffing up the timestamps. Output a `<Module>.date' timestamp file. Also, eliminate the circular interface dependency warning, since it was giving false hits on circular implementation dependencies. GNUMakefile, Makefile.common, Makefile.mercury: Fix a bug or two. Update the interface files intelligently.
144 lines
4.2 KiB
Mathematica
144 lines
4.2 KiB
Mathematica
%---------------------------------------------------------------------------%
|
|
%---------------------------------------------------------------------------%
|
|
%
|
|
% file pqueue.nl - implements a priority queue.
|
|
%
|
|
% A qpueue is a priority queue DDT with the smallest element at the root.
|
|
% It takes keys and values to provide a dictionary type function, and
|
|
% is not guarenteed to be stable. XXX this should be fixed.
|
|
%
|
|
%---------------------------------------------------------------------------%
|
|
%---------------------------------------------------------------------------%
|
|
|
|
:- module pqueue.
|
|
|
|
:- interface.
|
|
|
|
:- import_module list, std_util.
|
|
|
|
:- type pqueue(_K, _V).
|
|
|
|
% Create an empty priority queue
|
|
:- pred pqueue__init(pqueue(_K, _V)).
|
|
:- mode pqueue__init(out) is det.
|
|
|
|
% Insert a value V with key K into a priority queue
|
|
% and return the new priority queue.
|
|
:- pred pqueue__insert(pqueue(K, V), K, V, pqueue(K, V)).
|
|
:- mode pqueue__insert(in, in, in, out) is det.
|
|
|
|
% Remove the smallest item from the priority queue.
|
|
:- pred pqueue__remove(pqueue(K, V), K, V, pqueue(K, V)).
|
|
:- mode pqueue__remove(in, out, out, out) is semidet.
|
|
|
|
% Extract all the items from a priority queue by
|
|
% repeated removal, and place them in an associative
|
|
% list.
|
|
:- pred pqueue__to_assoc_list(pqueue(K, V), assoc_list(K, V)).
|
|
:- mode pqueue__to_assoc_list(in, out) is det.
|
|
|
|
% Insert all the key-value pairs in an association list
|
|
% into a priority queue.
|
|
:- pred pqueue__assoc_list_to_pqueue(assoc_list(K, V), pqueue(K, V)).
|
|
:- mode pqueue__assoc_list_to_pqueue(in, out) is det.
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
:- implementation.
|
|
|
|
:- import_module int.
|
|
|
|
:- type pqueue(K, V) ---> empty
|
|
; pqueue(int, K, V, pqueue(K, V), pqueue(K, V)).
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
pqueue__init(empty).
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
pqueue__insert(empty, K, V, pqueue(0, K, V, empty, empty)).
|
|
pqueue__insert(pqueue(D0, K0, V0, L0, R0), K, V, PQ) :-
|
|
D is D0 + 1,
|
|
compare(CMP, K, K0),
|
|
(
|
|
CMP = (<)
|
|
->
|
|
K1 = K,
|
|
V1 = V,
|
|
pqueue__insert_2(K0, V0, L0, R0, L, R)
|
|
;
|
|
K1 = K0,
|
|
V1 = V0,
|
|
pqueue__insert_2(K, V, L0, R0, L, R)
|
|
),
|
|
PQ = pqueue(D, K1 ,V1, L, R).
|
|
|
|
:- pred pqueue__insert_2(K, V, pqueue(K, V), pqueue(K, V),
|
|
pqueue(K, V), pqueue(K, V)).
|
|
:- mode pqueue__insert_2(in, in, in, in, out, out) is det.
|
|
|
|
pqueue__insert_2(K, V, empty, empty, pqueue(0, K, V, empty, empty), empty).
|
|
pqueue__insert_2(K, V, pqueue(D0, K0, V0, L0, R0), empty,
|
|
pqueue(D0, K0, V0, L0, R0), pqueue(0, K, V, empty, empty)).
|
|
pqueue__insert_2(K, V, empty, pqueue(D0, K0, V0, L0, R0),
|
|
pqueue(0, K, V, empty, empty), pqueue(D0, K0, V0, L0, R0)).
|
|
pqueue__insert_2(K, V, pqueue(D0, K0, V0, L0, R0), pqueue(D1, K1, V1, L1, R1),
|
|
PQ1, PQ2) :-
|
|
(
|
|
D0 > D1
|
|
->
|
|
pqueue__insert(pqueue(D1, K1, V1, L1, R1), K, V, PQ2),
|
|
PQ1 = pqueue(D0, K0, V0, L0, R0)
|
|
;
|
|
pqueue__insert(pqueue(D0, K0, V0, L0, R0), K, V, PQ1),
|
|
PQ2 = pqueue(D1, K1, V1, L1, R1)
|
|
).
|
|
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
pqueue__remove(pqueue(_, K, V, L0, R0), K, V, PQ) :-
|
|
pqueue__remove_2(L0, R0, PQ).
|
|
|
|
:- pred pqueue__remove_2(pqueue(K, V), pqueue(K, V), pqueue(K, V)).
|
|
:- mode pqueue__remove_2(in, in, out) is det.
|
|
|
|
pqueue__remove_2(empty, empty, empty).
|
|
pqueue__remove_2(empty, pqueue(D, K, V, L, R), pqueue(D, K, V, L, R)).
|
|
pqueue__remove_2(pqueue(D, K, V, L, R), empty, pqueue(D, K, V, L, R)).
|
|
pqueue__remove_2(pqueue(D0, K0, V0, L0, R0), pqueue(D1, K1, V1, L1, R1), PQ) :-
|
|
compare(CMP, K0, K1),
|
|
(
|
|
CMP = (<)
|
|
->
|
|
D0M1 is D0 - 1,
|
|
int__max(D0M1, D1, D),
|
|
pqueue__remove_2(L0, R0, PQ0),
|
|
PQ = pqueue(D, K0, V0, PQ0, pqueue(D1, K1, V1, L1, R1))
|
|
;
|
|
D1M1 is D0 - 1,
|
|
int__max(D1M1, D1, D),
|
|
pqueue__remove_2(L1, R1, PQ1),
|
|
PQ = pqueue(D, K1, V1, PQ1, pqueue(D0, K0, V0, L0, R0))
|
|
).
|
|
|
|
%---------------------------------------------------------------------------%
|
|
|
|
pqueue__to_assoc_list(Q0, L) :-
|
|
(
|
|
pqueue__remove(Q0, K, V, Q1)
|
|
->
|
|
pqueue__to_assoc_list(Q1, L0),
|
|
L = [K - V | L0]
|
|
;
|
|
L = []
|
|
).
|
|
|
|
pqueue__assoc_list_to_pqueue([], Q) :-
|
|
pqueue__init(Q).
|
|
pqueue__assoc_list_to_pqueue([K - V | L], Q) :-
|
|
pqueue__assoc_list_to_pqueue(L, Q0),
|
|
pqueue__insert(Q0, K, V, Q).
|
|
|