apply

apply(v,f) -- applies the function f to each element of the list v, returning the list of results. If v is a sequence, then a sequence is returned.

     i1 = apply(1 .. 5, i->i^2)
     
     o1 = 1,4,9,16,25
     
     o1 : Sequence

     i2 = apply({1,3,5,7}, i->i^2)
     
     o2 = {1,9,25,49}
     
     o2 : List

apply(v,w,f) -- produces, from lists or sequences v and w, a list z in which the i-th element w_i is obtained by evaluating f(v_i,w_i). If v and w are lists of the same class, then the result is also of that class. If v and w are sequences, then so is the result.

     i3 = apply(1 .. 5, a .. e, identity)
     
     o3 = (1,a),(2,b),(3,c),(4,d),(5,e)
     
     o3 : Sequence

     i4 = apply({1,3,5,7}, i->i^2)
     
     o4 = {1,9,25,49}
     
     o4 : List

apply(n,f) -- equivalent to apply(list (0 .. n-1),f), for an integer n.

See also scan, select, any, all, and member.

apply(x,f) -- produces a new hash table y from an hash table x by applying the function f to each of the values of x. This means that if x#k === v then y#k === f(v). If f(v) is null, then no entry is made in y.