Sorting predicates in PROLOG

[EricGT]

This is cross posted on StackOverflow

Sorting predicates in PROLOG

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@elfi

I am new to prolog, is there any function to sort predicates ?

Yes.

order_by/2

Order_by/2 examples

Here are some examples for order_by/2 from library(solution_sequences) as test cases. :- begin_tests(order_by). % run_tests(order_by). data(0, 1, 1). data(1, 0, 0). data(0, 0, 0). data(1, 1, 0). data(1, 0, 1). data(0, 0, 1). data(1, 1, 1). data(0, 1, 0). % Bag ordering: same order as data % Item output format: List % Item element order: A,B,C % Data source: facts test(1,[ all( Cs == [[[0,1,1],[1,0,0],[0,0,0],[1,1,0],[1,0,1],[0,0,1],[1,1,1],[0,1,0]]] ) ] ) :- bagof([A,B,C], data(A, B, C), Cs…

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Note: order_by/2 will not work with your predicates because they have different names, i.e. p1, p2, …
They need to have the same functor for order_by/2 to work, e.g.

p( 201, 5, 2 ).
p( 301, 1, 2 ).
p( 401, 1, 4 ).
p( 501, 1, 5 ).