Files
mercury/library/array2d.m
Julien Fischer f89054f165 Use error($pred, "...") in more spots in the standard library.
Also, throw software_error/1 exceptions rather than directly throwing strings
in a few spots.

Undo special Ralph-style formatting.

library/*.:
    As above.

tests/hard_coded/array2d_from_array.exp:
tests/hard_coded/array2d.exp:
tests/hard_coded/test_injection.exp:
   Update to conform with the above change.
2019-10-15 17:48:36 +11:00

287 lines
9.1 KiB
Mathematica

%---------------------------------------------------------------------------%
% vim: ft=mercury ts=4 sw=4 et
%---------------------------------------------------------------------------%
% Copyright (C) 2003, 2005-2007, 2011-2012 The University of Melbourne.
% Copyright (C) 2013-2018 The Mercury team.
% This file is distributed under the terms specified in COPYING.LIB.
%---------------------------------------------------------------------------%
%
% File: array2d.m.
% Author: Ralph Becket <rafe@cs.mu.oz.au>.
% Stability: medium-low.
%
% Two-dimensional rectangular (i.e. not ragged) array ADT.
%
% XXX The same caveats re: uniqueness of arrays apply to array2ds.
%
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%
:- module array2d.
:- interface.
:- import_module array.
:- import_module list.
%---------------------------------------------------------------------------%
% An array2d is a two-dimensional array stored in row-major order
% (that is, the elements of the first row in left-to-right
% order, followed by the elements of the second row and so forth.)
%
:- type array2d(T).
:- inst array2d for array2d/1
---> array2d(ground, ground, array).
% XXX These are work-arounds until we get nested uniqueness working.
%
:- mode array2d_di == di(array2d).
:- mode array2d_ui == in(array2d).
:- mode array2d_uo == out(array2d).
% init(M, N, X) = array2d([[X11, ..., X1N], ..., [XM1, ..., XMN]])
% where each XIJ = X. An exception is thrown if M < 0 or N < 0.
%
:- func init(int, int, T) = array2d(T).
:- mode init(in, in, in) = array2d_uo is det.
% array2d([[X11, ..., X1N], ..., [XM1, ..., XMN]]) constructs an array2d
% of size M * N, with the special case that bounds(array2d([]), 0, 0).
%
% An exception is thrown if the sublists are not all the same length.
%
:- func array2d(list(list(T))) = array2d(T).
:- mode array2d(in) = array2d_uo is det.
% A synonym for the above.
%
:- func from_lists(list(list(T))) = array2d(T).
:- mode from_lists(in) = array2d_uo is det.
% from_array(M, N, Array) constructs an array2d of size M * N where the
% elements are taken from Array in row-major order, i.e. the element at row
% I column J is taken from Array at index (I * N + J). Indices start from
% zero. Throws an exception if M < 0 or N < 0, or if the number of elements
% in Array does not equal M * N.
%
:- func from_array(int, int, array(T)) = array2d(T).
:- mode from_array(in, in, array_di) = array2d_uo is det.
% is_empty(Array):
% True iff Array contains zero elements.
%
:- pred is_empty(array2d(T)).
%:- mode is_empty(array2d_ui) is semidet.
:- mode is_empty(in) is semidet.
% bounds(array2d([[X11, ..., X1N], ..., [XM1, ..., XMN]), M, N)
%
:- pred bounds(array2d(T), int, int).
%:- mode bounds(array2d_ui, out, out) is det.
:- mode bounds(in, out, out) is det.
% in_bounds(array2d([[X11, ..., X1N], ..., [XM1, ..., XMN]), I, J)
% succeeds iff 0 =< I < M, 0 =< J < N.
%
:- pred in_bounds(array2d(T), int, int).
%:- mode in_bounds(array2d_ui, in, in ) is semidet.
:- mode in_bounds(in, in, in ) is semidet.
% array2d([[X11, ..., X1N], ..., [XM1, ..., XMN]]) ^ elem(I, J) = X
% where X is the J+1'th element of the I+1'th row (that is, indices
% start from zero.)
%
% An exception is thrown unless 0 =< I < M, 0 =< J < N.
%
:- func array2d(T) ^ elem(int, int) = T.
%:- mode array2d_ui ^ elem(in, in ) = out is det.
:- mode in ^ elem(in, in ) = out is det.
% T ^ unsafe_elem(I, J) is the same as T ^ elem(I, J) except that
% behaviour is undefined if not in_bounds(T, I, J).
%
:- func array2d(T) ^ unsafe_elem(int, int) = T.
%:- mode array2d_ui ^ unsafe_elem(in, in ) = out is det.
:- mode in ^ unsafe_elem(in, in ) = out is det.
% ( T0 ^ elem(I, J) := X ) = T
% where T ^ elem(II, JJ) = X if I = II, J = JJ
% and T ^ elem(II, JJ) = T0 ^ elem(II, JJ) otherwise.
%
% An exception is thrown unless 0 =< I < M, 0 =< J < N.
%
:- func ( array2d(T) ^ elem(int, int) := T ) = array2d(T).
:- mode ( array2d_di ^ elem(in, in) := in ) = array2d_uo is det.
% Pred version of the above.
%
:- pred set(int, int, T, array2d(T), array2d(T)).
:- mode set(in, in, in, array2d_di, array2d_uo) is det.
% T ^ unsafe_elem(I, J) := X is the same as T ^ elem(I, J) := X except
% that behaviour is undefined if not in_bounds(T, I, J).
%
:- func ( array2d(T) ^ unsafe_elem(int, int) := T ) = array2d(T).
:- mode ( array2d_di ^ unsafe_elem(in, in) := in ) = array2d_uo is det.
% Pred version of the above.
%
:- pred unsafe_set(int, int, T, array2d(T), array2d(T)).
:- mode unsafe_set(in, in, in, array2d_di, array2d_uo) is det.
% lists(array2d([[X11, ..., X1N], ..., [XM1, ..., XMN])) =
% [[X11, ..., X1N], ..., [XM1, ..., XMN]]
%
:- func lists(array2d(T)) = list(list(T)).
%:- mode lists(array2d_ui) = out is det.
:- mode lists(in ) = out is det.
% fill(Item, !Array2d):
% Sets every element of the array to Item.
%
:- pred fill(T::in, array2d(T)::array2d_di, array2d(T)::array2d_uo) is det.
%---------------------------------------------------------------------------%
%---------------------------------------------------------------------------%
:- implementation.
:- import_module require.
:- import_module int.
:- interface.
% This should be abstract, but needs to be exported for insts.
%
:- type array2d(T)
---> array2d(
int, % rows
int, % cols
array(T) % array
).
:- implementation.
%---------------------------------------------------------------------------%
init(M, N, X) =
( if M >= 0, N >= 0 then
array2d(M, N, array.init(M * N, X))
else
func_error($pred, "bounds must be non-negative")
).
%---------------------------------------------------------------------------%
array2d([]) = array2d(0, 0, make_empty_array).
array2d(Xss @ [Xs | _]) = T :-
M = length(Xss),
N = length(Xs),
A = array(condense(Xss)),
( if all [Ys] ( member(Ys, Xss) => length(Ys) = N ) then
T = array2d(M, N, A)
else
error($pred, "non-rectangular list of lists")
).
from_lists(Xss) = array2d(Xss).
from_array(M, N, Array) = Array2d :-
( if
M >= 0,
N >= 0
then
array.size(Array, Size),
compare(Result, Size, M * N),
(
Result = (=),
Array2d = array2d(M, N, Array)
;
Result = (>),
error($pred, "too many elements")
;
Result = (<),
error($pred, "too few elements")
)
else
error($pred, " bounds must be non-negative")
).
%---------------------------------------------------------------------------%
is_empty(array2d(_, _, A)) :-
array.is_empty(A).
%---------------------------------------------------------------------------%
bounds(array2d(M, N, _A), M, N).
%---------------------------------------------------------------------------%
in_bounds(array2d(M, N, _A), I, J) :-
0 =< I, I < M,
0 =< J, J < N.
%---------------------------------------------------------------------------%
T ^ elem(I, J) =
( if in_bounds(T, I, J) then
T ^ unsafe_elem(I, J)
else
func_error($pred, "indices out of bounds")
).
%---------------------------------------------------------------------------%
array2d(_M, N, A) ^ unsafe_elem(I, J) = A ^ unsafe_elem(I * N + J).
%---------------------------------------------------------------------------%
( T ^ elem(I, J) := X ) =
( if in_bounds(T, I, J) then
T ^ unsafe_elem(I, J) := X
else
func_error("array2d.'elem :=': indices out of bounds")
).
set(I, J, X, A, A ^ elem(I, J) := X).
%---------------------------------------------------------------------------%
( array2d(M, N, A) ^ unsafe_elem(I, J) := X ) =
array2d(M, N, A ^ unsafe_elem(I * N + J) := X).
unsafe_set(I, J, X, A, A ^ unsafe_elem(I, J) := X).
%---------------------------------------------------------------------------%
lists(array2d(M, N, A)) = lists_2((M * N) - 1, N - 1, N, A, [], []).
:- func lists_2(int, int, int, array(T), list(T), list(list(T))) =
list(list(T)).
%:- mode lists_2(in, in, in, array_ui, in, in ) = out is det.
:- mode lists_2(in, in, in, in, in, in ) = out is det.
lists_2(IJ, J, N, A, Xs, Xss) =
( if 0 =< IJ then
( if 0 =< J
then lists_2(IJ - 1, J - 1, N, A, [A ^ elem(IJ) | Xs], Xss )
else lists_2(IJ, N - 1, N, A, [], [Xs | Xss])
)
else
[Xs | Xss]
).
%---------------------------------------------------------------------------%
fill(Item, A0, A) :-
A0 = array2d(M, N, Array0),
array.fill(Item, Array0, Array),
A = array2d(M, N, Array).
%---------------------------------------------------------------------------%
:- end_module array2d.
%---------------------------------------------------------------------------%