Did you know ... Search Documentation:
apply.pl -- Apply predicates on a list
PublicShow source

This module defines meta-predicates that apply a predicate on all members of a list.

See also
- apply_macros.pl provides compile-time expansion for part of this library.
- http://www.cs.otago.ac.nz/staffpriv/ok/pllib.htm
To be done
- Add include/4, include/5, exclude/4, exclude/5
Source include(:Goal, +List1, ?List2) is det
Filter elements for which Goal succeeds. True if List2 contains those elements Xi of List1 for which call(Goal, Xi) succeeds.
See also
- Older versions of SWI-Prolog had sublist/3 with the same arguments and semantics.
Source exclude(:Goal, +List1, ?List2) is det
Filter elements for which Goal fails. True if List2 contains those elements Xi of List1 for which call(Goal, Xi) fails.
Source partition(:Pred, +List, ?Included, ?Excluded) is det
Filter elements of List according to Pred. True if Included contains all elements for which call(Pred, X) succeeds and Excluded contains the remaining elements.
Source partition(:Pred, +List, ?Less, ?Equal, ?Greater) is semidet
Filter List according to Pred in three sets. For each element Xi of List, its destination is determined by call(Pred, Xi, Place), where Place must be unified to one of <, = or >. Pred must be deterministic.
Source maplist(:Goal, ?List)
True if Goal can successfully be applied on all elements of List. Arguments are reordered to gain performance as well as to make the predicate deterministic under normal circumstances.
Source maplist(:Goal, ?List1, ?List2)
As maplist/2, operating on pairs of elements from two lists.
Source maplist(:Goal, ?List1, ?List2, ?List3)
As maplist/2, operating on triples of elements from three lists.
Source maplist(:Goal, ?List1, ?List2, ?List3, ?List4)
As maplist/2, operating on quadruples of elements from four lists.
Source convlist(:Goal, +ListIn, -ListOut) is det
Similar to maplist/3, but elements for which call(Goal, ElemIn, _) fails are omitted from ListOut. For example (using library(yall)):
?- convlist([X,Y]>>(integer(X), Y is X^2),
            [3, 5, 4.4, 2], L).
L = [9, 25, 4].
Compatibility
- Also appears in YAP library(maplist) and SICStus library(lists).
Source foldl(:Goal, +List, +V0, -V)
Source foldl(:Goal, +List1, +List2, +V0, -V)
Source foldl(:Goal, +List1, +List2, +List3, +V0, -V)
Source foldl(:Goal, +List1, +List2, +List3, +List4, +V0, -V)
Fold a list, using arguments of the list as left argument. The foldl family of predicates is defined by:
foldl(P, [X11,...,X1n], ..., [Xm1,...,Xmn], V0, Vn) :-
      P(X11, ..., Xm1, V0, V1),
      ...
      P(X1n, ..., Xmn, V', Vn).
Source scanl(:Goal, +List, +V0, -Values)
Source scanl(:Goal, +List1, +List2, +V0, -Values)
Source scanl(:Goal, +List1, +List2, +List3, +V0, -Values)
Source scanl(:Goal, +List1, +List2, +List3, +List4, +V0, -Values)
Left scan of list. The scanl family of higher order list operations is defined by:
scanl(P, [X11,...,X1n], ..., [Xm1,...,Xmn], V0,
      [V0,V1,...,Vn]) :-
      P(X11, ..., Xm1, V0, V1),
      ...
      P(X1n, ..., Xmn, V', Vn).

Undocumented predicates

The following predicates are exported, but not or incorrectly documented.

Source foldl(Arg1, Arg2, Arg3, Arg4, Arg5)
Source foldl(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6)
Source scanl(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6)
Source foldl(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7)
Source scanl(Arg1, Arg2, Arg3, Arg4, Arg5)
Source scanl(Arg1, Arg2, Arg3, Arg4, Arg5, Arg6, Arg7)