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defaulty

This example compares defaulty and tagged data representations using the ports_profiler tool. The example defines both defaulty and tagged objects implementing the same predicate. This predicate, count_atomics/3, counts the number of atoms and the number of numbers in a list that can contain atoms, numbers, and other types of terms that are irrelevant. Running the same query for both representations, the ports_profiler tool is used to highlight their performance difference.

For a detailed analysis of this example, see the following blog post:

https://logtalk.org/2019/12/17/the-cost-of-defaulty-representations.html

Print Logtalk, Prolog backend, and kernel versions (if running as a notebook):

%versions

Start by loading the example and the ports_profiler tool:

logtalk_load(defaulty(loader)).

Activate the ports profiler:

ports_profiler::start.

Get ports profiling data for the defaulty representation:

defaulty::count_atomics([a,1,_,b,2,_,c,3,_], As, Ns).

Print the profiling data:

ports_profiler::data.

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Entity Predicate Fact Rule Call Exit *Exit Fail Redo Error

defaulty count_atomic/5 3 15 9 9 0 0 0 0 defaulty count_atomics/3 0 1 1 1 0 0 0 0 defaulty count_atomics/5 1 9 10 10 0 0 0 0 ---------------------------------------------------------------------------

true. -->

Reset the profiling data for the next query:

ports_profiler::reset.

Get ports profiling data for the tagged representation:

tagged::count_atomics([a(a),n(1),o(_),a(b),n(2),o(_),a(c),n(3),o(_)], As, Ns).

Print the profiling data:

ports_profiler::data.

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Entity Predicate Fact Rule Call Exit *Exit Fail Redo Error

tagged count_atomic/5 3 6 9 9 0 0 0 0 tagged count_atomics/3 0 1 1 1 0 0 0 0 tagged count_atomics/5 1 9 10 10 0 0 0 0 -------------------------------------------------------------------------

true. -->

Deactivate the ports profiler:

ports_profiler::stop.