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

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

Synopsis:

Function: fold -- apply binary operator repeatedly

Input:

an instance of class Function.

an instance of class VisibleList.

Output:

an instance of class VisibleList.

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

i1 : fold(identity, {a,b,c,d,e})



o1 = ((((a, b), c), d), e)



o1 : Sequence

i2 : fold(plus, {1,2,3,4,5})



o2 = 15

Code:

     -- ../../../Macaulay2/m2/fold.m2:16-18
     fold(Function,VisibleList) := VisibleList => (f,v) -> (
          if # v === 0 then error "expected a nonempty list";
          fold(f,v#0,drop(v,1)))