Each versus Reduce

gistfile1.txt

/* On Array */

VALUE
rb_ary_each(ary)
    VALUE ary;
{
    long i;

    for (i=0; i<RARRAY(ary)->len; i++) {
        rb_yield(RARRAY(ary)->ptr[i]);
    }
    return ary;
}

/* On Enumerable */

static VALUE
enum_inject(argc, argv, obj)
    int argc;
    VALUE *argv, obj;
{
    VALUE memo = Qundef;

    if (rb_scan_args(argc, argv, "01", &memo) == 0)
        memo = Qundef;
    rb_iterate(rb_each, obj, inject_i, (VALUE)&memo);
    if (memo == Qundef) return Qnil;
    return memo;
}