link printf

procedure main()
   fsf1 := partial(fs,f1)
   fsf2 := partial(fs,f2)
   every s :=  [ 0, 1, 2, 3 ] |
               [ 2, 4, 6, 8 ] do {
         printf("\ns       := %s\n",list2string(s))
         printf("fsf1(s) := %s\n",list2string(fsf1(s)))
         printf("fsf2(s) := %s\n",list2string(fsf2(s)))
      }
end

procedure partial(f,g)  #: partial application of f & g
   @( p := create repeat {
                  s := (r@&source)[1]  # return r / get argument s
                  r := f(g,s)          # apply f(g,...)
                  }
      )                                # create and activate procedure p
   return p
end

procedure fs(f,s)       #: return list where f is applied to each element of s
   every put(r := [], f(!s))
   return r
end

procedure f1(n)         # double
   return n * 2
end

procedure f2(n)         #: square
   return n ^ 2
end

procedure list2string(L)         #: format list as a string
   every (s := "[ ") ||:= !L || " "
   return s || "]"
end