foldall/4

Availability::- use_module(library(aggregate)).(can be autoloaded)

[det]foldall(:Folder, :Goal, +V0, -V)

Use Folder to fold V0 to V using all answers of Goal. This predicate generates all answers for Goal and for each answer it calls call(Folder,V0,V1). This predicate provides behaviour similar to aggregate_all/3-4, but operates in constant space and allows for custom aggregation (Folder) operators. The example below uses plus/3 to realise aggregate_all(sum(X), between(1,10,X), Sum).

?- foldall(plus(X), between(1,10,X), 0, Sum).
Sum = 55

The implementation uses nb_setarg/3 for non-backtrackable state updates.

See also: aggregate_all/3-4, foldl/4-7, nb_setarg/3.