/*
 *  call-seq:
 *    each_cons(n) {...}
 *
 *  Iterates the given block for each array of consecutive <n>
 *  elements.
 *
 *  e.g.:
 *      (1..10).each_cons(3) {|a| p a}
 *      # outputs below
 *      [1, 2, 3]
 *      [2, 3, 4]
 *      [3, 4, 5]
 *      [4, 5, 6]
 *      [5, 6, 7]
 *      [6, 7, 8]
 *      [7, 8, 9]
 *      [8, 9, 10]
 *
 */
static VALUE
enum_each_cons(obj, n)
    VALUE obj, n;
{
    long size = NUM2LONG(n);
    NODE *memo;

    if (size <= 0) rb_raise(rb_eArgError, "invalid size");
    memo = rb_node_newnode(NODE_MEMO, rb_ary_new2(size), 0, size);

    rb_iterate(rb_each, obj, each_cons_i, (VALUE)memo);

    return Qnil;
}