What does this syntax mean? (Prolog)
I have been trying to learn Prolog and came across this syntax on some example code.
solve(Hs) :- Hs = [_,_,开发者_运维技巧_,_,_],
member(h(_, _, _, _, dog), Hs).
This is only a portion of the code, but I'm confused with the h(_,_,_,_,dog)
does.
Any help would be greatly appreciated!
The underscores _
just indicate that there is a value in that position, but we don't care about it.
The first part effectively says that Hs
is a 5 item list. The second part says that in that list of Hs
, one of the items is a compound term h/5
(h with 5 subterms) where the last is the atom, dog
.
All the underscores can match anything. It is a wild card. You are basically looking for a fact(?) with the last part equal to dog.
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