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Estimated hours taken: 0.1 Add the DPPD (dozens of problems in partial deduction) suite to the tests directory.
79 lines
2.0 KiB
Mathematica
79 lines
2.0 KiB
Mathematica
/*
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The "maxlength" Benchmark
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Part of the DPPD Library.
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General Description
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A simple benchmark testing whether a partial deducer can perform
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tupling. The benchmark program traverses a list twice to get its
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length as well as the maximum value of the list. By tupling these
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traversals are merged into a single traversal. The benchmark program
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uses built-ins but no negations. This particular benchmark program is
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treated in more detail in the technical report CW 225.
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The benchmark program
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*/
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:- module maxlength.
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:- interface.
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:- pred maxlength is semidet.
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:- implementation.
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:- import_module list, max_length_impl, run.
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maxlength :-
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max_length([1,2,3,4,3,2,1],Max1,Len1),
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use(Max1),
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use(Len1),
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max_length([],Max2,Len2),
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use(Max2),
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use(Len2),
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max_length([1,5,3,2,6,3,7,3,2,1,8,5,3,5,2,3],Max3,Len3),
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use(Max3),
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use(Len3),
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max_length([1,5,3,2,6,3,7,3,2,1,8,5,3,5,2,3],Max4,5),
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use(Max4),
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max_length([1,5,3,2,6,3,7,3,2,1,8,5,3,5,2,3],3,Len5),
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use(Len5).
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/*
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The partial deduction query
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:- max_length(L,Max,Len).
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The run-time queries
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:- max_length([1,2,3,4,3,2,1],Max,Len).
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:- max_length([],Max,Len).
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:- max_length([1,5,3,2,6,3,7,3,2,1,8,5,3,5,2,3],Max,Len).
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:- max_length([1,5,3,2,6,3,7,3,2,1,8,5,3,5,2,3],Max,5).
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:- max_length([1,5,3,2,6,3,7,3,2,1,8,5,3,5,2,3],3,Len).
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Example solution
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With the ECCE partial deduction system one can obtain the following
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tupled program (which runs 20 % faster on Sicstus Prolog, but
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unfortunately 10 % slower on Prolog by BIM - the problem is probably
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due to caching behaviour of the Sparc processor):
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max_length__1(X1,X2,X3) :- max1_conj__2(X1,0,X2,X3).
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max1_conj__2([],X1,X1,0).
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max1_conj__2([X1|X2],X3,X4,X5) :-
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X1 =< X3,
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max1_conj__2(X2,X3,X4,X6),
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X5 is '+'(X6,1).
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max1_conj__2([X1|X2],X3,X4,X5) :-
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X1 > X3,
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max1_conj__2(X2,X1,X4,X6),
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X5 is '+'(X6,1).
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_________________________________________________________________
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Michael Leuschel / K.U. Leuven / michael@cs.kuleuven.ac.be
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*/
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