Erlang (programming language)/Tutorials/Folding

Fun with folding

Fold is a powerful tool, when you get to know it. lists:foldr(F,S,L) takes three arguments: F is some folding function, S is some starting value, and L is some List that needs folding. Let us do some simple folding. The following fold calculates the lenght of a list. Here the current list item, _C is ignored, and the accumulator, A, counts the number of elements in the list.

 lists:foldr( fun(_C,A)->A+1 end, 0, [1,2,3]).
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