FoldWhileList¶

Like FoldList, but stops once the predicate returns False.

$ wo 'FoldWhileList[Plus, 0, {1, 2, 3, 4}, # < 5 &]'
{0, 1, 3, 6}

A fifth argument gives the test the last m results (or All of them), and a sixth shifts where the fold stops — negative to stop earlier:

$ wo 'FoldWhileList[#1 + #2 &, 0, {1, 2, 3, 4}, # < 4 &, 1, -1]'
{0, 1, 3}

The operator form folds a list, taking its first element as the start:

$ wo 'FoldWhileList[#1 + #2 &, # < 4 &][{1, 2, 3, 4}]'
{1, 3, 6}