fold(VisibleList,Function) -- apply binary operator repeatedly

fold(VisibleList,Function) -- apply binary operator repeatedly

Synopsis:

Function: fold -- apply binary operator repeatedly

Input:

an instance of class VisibleList.

an instance of class Function.

Output:

an instance of class VisibleList.

fold({xn,...,x1,x0},f) -- computes f(...f(x2,f(x1,x0))...)}.

i1 : fold({a,b,c,d,e}, identity)



o1 = (a, (b, (c, (d, e))))



o1 : Sequence

Code:

     -- ../../../Macaulay2/m2/fold.m2:19-21
     fold(VisibleList,Function) := VisibleList => (v,f) -> (
          if #v === 0 then error "expected a nonempty list";
          fold(drop(v,-1),v#-1,f))