Re-exported predicates

The following predicates are exported from this file while their implementation is defined in imported modules or non-module files loaded by this module.

 complement(+UGraphIn, -UGraphOut)

UGraphOut is a ugraph with an edge between all vertices that are not connected in UGraphIn and all edges from UGraphIn removed. Example:

?- complement([1-[3,5],2-[4],3-[],
               4-[1,2,7,5],5-[],6-[],7-[],8-[]], NL).
NL = [1-[2,4,6,7,8],2-[1,3,5,6,7,8],3-[1,2,4,5,6,7,8],
      4-[3,5,6,8],5-[1,2,3,4,6,7,8],6-[1,2,3,4,5,7,8],
      7-[1,2,3,4,5,6,8],8-[1,2,3,4,5,6,7]]

To be done

- Simple two-step algorithm. You could be smarter, I suppose.

 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.

See also

- include/3, exclude/3, partition/5.

 foldl(:Goal, +List, +V0, -V)

 foldl(:Goal, +List1, +List2, +V0, -V)

 foldl(:Goal, +List1, +List2, +List3, +V0, -V)

 foldl(:Goal, +List1, +List2, +List3, +List4, +V0, -V)

Fold an ensemble of m (0 <= m <= 4) lists of length n head-to-tail ("fold-left"), using columns of m list elements as arguments for Goal. The foldl family of predicates is defined as follows, with V0 an initial value and V the final value of the folding operation:

foldl(G, [X_11, ..., X_1n],
         [X_21, ..., X_2n],
         ...,
         [X_m1, ..., X_mn], V0, V) :-
   call(G, X_11, ..., X_m1, V0, V1),
   call(G, X_12, ..., X_m2, V1, V2),
   ...
   call(G, X_1n, ..., X_mn, V<n-1>, V).

No implementation for a corresponding foldr is given. A foldr implementation would consist in first calling reverse/2 on each of the m input lists, then applying the appropriate foldl. This is actually more efficient than using a properly programmed-out recursive algorithm that cannot be tail-call optimized.

Undocumented predicates

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

 lpa_apply(Arg1)

 lpa_apply(Arg1, Arg2)

 identity(Arg1, Arg2)

 complement(Arg1)

 every(Arg1, Arg2)

 some(Arg1, Arg2)

 somechk(Arg1, Arg2)

 map(Arg1, Arg2, Arg3)

 filter(Arg1, Arg2, Arg3)

 mapfilter(Arg1, Arg2, Arg3)

 foldl1(Arg1, Arg2, Arg3)

 foldr(Arg1, Arg2, Arg3, Arg4)

 foldr1(Arg1, Arg2, Arg3)