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If you like this stuff, consider how to "implement" JSON in Prolog: :- op(400, yfx, :). ?- JSON = { a: 1, b: "a string", c: { d: "a compoun

If you like this stuff, consider how to "implement" JSON in Prolog: :- op(400, yfx, :). ?- JSON = { a: 1, b: "a string", c: { d: "a compound" } }, JSON = { a: X, b: Y, c: { d: Z }} Basically, you don't ;) all we did here is declaring ':' as an infix operator. The next lines bind/unify a term to the var JSON, and the last line is again unification in action (basically destructuring on steroids), binding the vars X, Y, and Z to the respective value 1, "a string", and "a compound" from the previously bound JSON var. You can paste this snippet into [1] and execute it right in your browser to check that indeed X, Y, and Z are bound as described if you wish. Not that it matters that much. Prolog is really for indeterministically searching a large/infinite space such as in planning (and yes it can be used for theorem proving and program verification as well). It's always fun to see newcomers trying to implement pointless low-level stuff such as list primitives when coming from a functional programming background or even getters/setters. [1]: https://quantumprolog.sgml.net/browser-demo/browser-demo.html https://quantumprolog.sgml.net/browser-demo/browser-demo.htm...

xlii 2y ago
> Prolog is for indeterministically… One side note here. Yes you can do indeterministic search but it’s not a property in Prolog. In fact, Prolog execution is completely deterministic without use of randomization. But I guess that in some domains (e.g. optimization) people would rather shuffle numbers than do a boring 1…1000000000 loops.
- bux93 2y ago
  The search order is neither indeterministic, nor deterministic; it is undefined. Some implementations do depth-first search, others go random. If your code is logically correct, it doesn't matter in the end - except if you use the cut-operator which essentially says 'don't look any further, just go with the first match', which will behave (in)deterministically based on the implementation.
deleted 2y ago
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YeGoblynQueenne 2y ago
>> Prolog is really for indeterministically searching a large/infinite space such as in planning (and yes it can be used for theorem proving and program verification as well). I'd say theorem proving is what Prolog "is really for", in the sense that it's a language whose interpreter is an automated theorem prover. It just so happens that a (first-order) theorem prover is the best tool to explore an infinite space, if it's worth its salt, because that's what it has to do in order to find a proof in the first place. And of course you can cast all sorts of combinatorial problems like planning and verification as proofs (this sequence of actions reaches this goal state from this starting state). Edit: incidentally, it's so dumb that the standard for pattern matching in the industry is regexes, with their insufferable, cryptic pandemonium of notations, rather than Prolog, which has got to be the language with the simplest possible syntax in all of computer science this side of Brainfuck. When I was doing my NLP homerwork during my MSc I kept writing small ad-hoc parsers that were all balls of mud around a bunch of regex scripts, and I longed for the simplicity of Prolog and its DCGs (I couldn't use Prolog because the homework was in Python and at the time there was no Janus). Why do programmers do that to themselves?

xlii 2y ago

> Prolog is for indeterministically… One side note here. Yes you can do indeterministic search but it’s not a property in Prolog. In fact, Prolog execution is completely deterministic without use of randomization. But I guess that in some domains (e.g. optimization) people would rather shuffle numbers than do a boring 1…1000000000 loops.

bux93 2y ago
The search order is neither indeterministic, nor deterministic; it is undefined. Some implementations do depth-first search, others go random. If your code is logically correct, it doesn't matter in the end - except if you use the cut-operator which essentially says 'don't look any further, just go with the first match', which will behave (in)deterministically based on the implementation.

deleted 2y ago

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YeGoblynQueenne 2y ago

>> Prolog is really for indeterministically searching a large/infinite space such as in planning (and yes it can be used for theorem proving and program verification as well). I'd say theorem proving is what Prolog "is really for", in the sense that it's a language whose interpreter is an automated theorem prover. It just so happens that a (first-order) theorem prover is the best tool to explore an infinite space, if it's worth its salt, because that's what it has to do in order to find a proof in the first place. And of course you can cast all sorts of combinatorial problems like planning and verification as proofs (this sequence of actions reaches this goal state from this starting state). Edit: incidentally, it's so dumb that the standard for pattern matching in the industry is regexes, with their insufferable, cryptic pandemonium of notations, rather than Prolog, which has got to be the language with the simplest possible syntax in all of computer science this side of Brainfuck. When I was doing my NLP homerwork during my MSc I kept writing small ad-hoc parsers that were all balls of mud around a bunch of regex scripts, and I longed for the simplicity of Prolog and its DCGs (I couldn't use Prolog because the homework was in Python and at the time there was no Janus). Why do programmers do that to themselves?