mirror of
https://github.com/Mercury-Language/mercury.git
synced 2025-12-15 05:44:58 +00:00
679eaeaec9
Estimated hours taken: 0.25 disj_gen: Remove redundant code. liveness: Trap some unreachable code. lookup_switch, tree: Move the code for testing code trees for emptyness to tree.m.
57 lines
1.8 KiB
Mathematica
57 lines
1.8 KiB
Mathematica
%-----------------------------------------------------------------------------%
|
|
% Copyright (C) 1995 University of Melbourne.
|
|
% This file may only be copied under the terms of the GNU General
|
|
% Public License - see the file COPYING in the Mercury distribution.
|
|
%-----------------------------------------------------------------------------%
|
|
%
|
|
% Main authors: conway, fjh.
|
|
%
|
|
% This file provides a 'tree' data type.
|
|
% The code generater uses this to build a tree of instructions and
|
|
% then flatten them into a list.
|
|
%
|
|
%-----------------------------------------------------------------------------%
|
|
%-----------------------------------------------------------------------------%
|
|
|
|
:- module tree.
|
|
:- import_module list.
|
|
|
|
%-----------------------------------------------------------------------------%
|
|
|
|
:- interface.
|
|
:- type tree(T) ---> empty
|
|
; node(T)
|
|
; tree(tree(T), tree(T)).
|
|
|
|
:- pred tree__flatten(tree(T), list(T)).
|
|
:- mode tree__flatten(in, out) is det.
|
|
|
|
:- pred tree__is_empty(tree(T)).
|
|
:- mode tree__is_empty(in) is semidet.
|
|
|
|
%-----------------------------------------------------------------------------%
|
|
|
|
:- implementation.
|
|
|
|
tree__flatten(T, L) :-
|
|
tree__flatten_2(T, [], L).
|
|
|
|
:- pred tree__flatten_2(tree(T), list(T), list(T)).
|
|
:- mode tree__flatten_2(in, in, out) is det.
|
|
% flatten_2(T, L0, L) is true iff L is the list that results from
|
|
% traversing T left-to-right depth-first, and then appending L0.
|
|
tree__flatten_2(empty, L, L).
|
|
tree__flatten_2(node(T), L, [T|L]).
|
|
tree__flatten_2(tree(T1,T2), L0, L) :-
|
|
tree__flatten_2(T2, L0, L1),
|
|
tree__flatten_2(T1, L1, L).
|
|
|
|
%-----------------------------------------------------------------------------%
|
|
|
|
tree__is_empty(empty).
|
|
tree__is_empty(tree(L, R)) :-
|
|
tree__is_empty(L),
|
|
tree__is_empty(R).
|
|
|
|
%-----------------------------------------------------------------------------%
|