Class: Enumerator::ArithmeticSequence

Inherits:
Enumerator show all
Defined in:
enumerator.c,
enumerator.c

Overview

Enumerator::ArithmeticSequence is a subclass of Enumerator, that is a representation of sequences of numbers with common difference. Instances of this class can be generated by the Range#step and Numeric#step methods.

The class can be used for slicing Array (see Array#slice) or custom collections.

Instance Method Summary collapse

Methods inherited from Enumerator

#+, #each_with_index, #each_with_object, #feed, #initialize, #initialize_copy, #next, #next_values, #peek, #peek_values, produce, #rewind, #with_index, #with_object

Methods included from Enumerable

#all?, #any?, #chain, #chunk, #chunk_while, #collect, #collect_concat, #count, #cycle, #detect, #drop, #drop_while, #each_cons, #each_entry, #each_slice, #each_with_index, #each_with_object, #entries, #filter, #filter_map, #find, #find_all, #find_index, #flat_map, #grep, #grep_v, #group_by, #include?, #inject, #lazy, #map, #max, #max_by, #member?, #min, #min_by, #minmax, #minmax_by, #none?, #one?, #partition, #reduce, #reject, #reverse_each, #select, #slice_after, #slice_before, #slice_when, #sort, #sort_by, #sum, #take, #take_while, #tally, #to_a, #to_h, #uniq, #zip

Constructor Details

This class inherits a constructor from Enumerator

Instance Method Details

#==(obj) ⇒ Boolean

Returns true only if obj is an Enumerator::ArithmeticSequence, has equivalent begin, end, step, and exclude_end? settings.

Returns:

  • (Boolean)

3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
# File 'enumerator.c', line 3811

static VALUE
arith_seq_eq(VALUE self, VALUE other)
{
    if (!RTEST(rb_obj_is_kind_of(other, rb_cArithSeq))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_begin(self), arith_seq_begin(other))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_end(self), arith_seq_end(other))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_step(self), arith_seq_step(other))) {
        return Qfalse;
    }

    if (arith_seq_exclude_end_p(self) != arith_seq_exclude_end_p(other)) {
        return Qfalse;
    }

    return Qtrue;
}

#==(obj) ⇒ Boolean

Returns true only if obj is an Enumerator::ArithmeticSequence, has equivalent begin, end, step, and exclude_end? settings.

Returns:

  • (Boolean)

3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
# File 'enumerator.c', line 3811

static VALUE
arith_seq_eq(VALUE self, VALUE other)
{
    if (!RTEST(rb_obj_is_kind_of(other, rb_cArithSeq))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_begin(self), arith_seq_begin(other))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_end(self), arith_seq_end(other))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_step(self), arith_seq_step(other))) {
        return Qfalse;
    }

    if (arith_seq_exclude_end_p(self) != arith_seq_exclude_end_p(other)) {
        return Qfalse;
    }

    return Qtrue;
}

#beginObject

#each {|i| ... } ⇒ Object #eachObject

Overloads:

  • #each {|i| ... } ⇒ Object

    Yields:

    • (i)

3879
3880
3881
3882
3883
3884
3885
3886
3887
3888
3889
3890
3891
3892
3893
3894
3895
3896
3897
3898
3899
3900
3901
3902
3903
3904
3905
3906
3907
3908
3909
3910
3911
3912
3913
3914
3915
3916
3917
3918
3919
3920
3921
3922
3923
3924
3925
3926
3927
3928
3929
3930
3931
3932
3933
# File 'enumerator.c', line 3879

static VALUE
arith_seq_each(VALUE self)
{
    VALUE c, e, s, len_1, last;
    int x;

    if (!rb_block_given_p()) return self;

    c = arith_seq_begin(self);
    e = arith_seq_end(self);
    s = arith_seq_step(self);
    x = arith_seq_exclude_end_p(self);

    if (!RB_TYPE_P(s, T_COMPLEX) && ruby_float_step(c, e, s, x, TRUE)) {
        return self;
    }

    if (NIL_P(e)) {
        while (1) {
            rb_yield(c);
            c = rb_int_plus(c, s);
        }

        return self;
    }

    if (rb_equal(s, INT2FIX(0))) {
        while (1) {
            rb_yield(c);
        }

        return self;
    }

    len_1 = num_idiv(num_minus(e, c), s);
    last = num_plus(c, num_mul(s, len_1));
    if (x && rb_equal(last, e)) {
        last = num_minus(last, s);
    }

    if (rb_num_negative_int_p(s)) {
        while (NUM_GE(c, last)) {
            rb_yield(c);
            c = num_plus(c, s);
        }
    }
    else {
        while (NUM_GE(last, c)) {
            rb_yield(c);
            c = num_plus(c, s);
        }
    }

    return self;
}

#endObject

#==(obj) ⇒ Boolean

Returns true only if obj is an Enumerator::ArithmeticSequence, has equivalent begin, end, step, and exclude_end? settings.

Returns:

  • (Boolean)

3811
3812
3813
3814
3815
3816
3817
3818
3819
3820
3821
3822
3823
3824
3825
3826
3827
3828
3829
3830
3831
3832
3833
3834
3835
# File 'enumerator.c', line 3811

static VALUE
arith_seq_eq(VALUE self, VALUE other)
{
    if (!RTEST(rb_obj_is_kind_of(other, rb_cArithSeq))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_begin(self), arith_seq_begin(other))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_end(self), arith_seq_end(other))) {
        return Qfalse;
    }

    if (!rb_equal(arith_seq_step(self), arith_seq_step(other))) {
        return Qfalse;
    }

    if (arith_seq_exclude_end_p(self) != arith_seq_exclude_end_p(other)) {
        return Qfalse;
    }

    return Qtrue;
}

#exclude_end?Boolean

Returns:

  • (Boolean)

#firstNumeric? #first(n) ⇒ Array

Returns the first number in this arithmetic sequence, or an array of the first n elements.

Overloads:


3452
3453
3454
3455
3456
3457
3458
3459
3460
3461
3462
3463
3464
3465
3466
3467
3468
3469
3470
3471
3472
3473
3474
3475
3476
3477
3478
3479
3480
3481
3482
3483
3484
3485
3486
3487
3488
3489
3490
3491
3492
3493
3494
3495
3496
3497
3498
3499
3500
3501
3502
3503
3504
3505
3506
3507
3508
3509
3510
3511
3512
3513
3514
3515
3516
3517
3518
3519
3520
3521
3522
3523
3524
3525
3526
3527
3528
3529
3530
3531
3532
3533
3534
3535
3536
3537
3538
3539
3540
3541
3542
3543
3544
3545
3546
3547
3548
3549
3550
3551
3552
3553
3554
3555
3556
3557
3558
3559
3560
3561
3562
3563
3564
3565
3566
3567
3568
3569
3570
3571
3572
3573
3574
3575
3576
3577
3578
3579
3580
3581
3582
3583
3584
3585
3586
# File 'enumerator.c', line 3452

static VALUE
arith_seq_first(int argc, VALUE *argv, VALUE self)
{
    VALUE b, e, s, ary;
    long n;
    int x;

    rb_check_arity(argc, 0, 1);

    b = arith_seq_begin(self);
    e = arith_seq_end(self);
    s = arith_seq_step(self);
    if (argc == 0) {
        if (NIL_P(b)) {
            return Qnil;
        }
        if (!NIL_P(e)) {
            VALUE zero = INT2FIX(0);
            int r = rb_cmpint(rb_num_coerce_cmp(s, zero, idCmp), s, zero);
            if (r > 0 && RTEST(rb_funcall(b, '>', 1, e))) {
                return Qnil;
            }
            if (r < 0 && RTEST(rb_funcall(b, '<', 1, e))) {
                return Qnil;
            }
        }
        return b;
    }

    // TODO: the following code should be extracted as arith_seq_take

    n = NUM2LONG(argv[0]);
    if (n < 0) {
        rb_raise(rb_eArgError, "attempt to take negative size");
    }
    if (n == 0) {
        return rb_ary_new_capa(0);
    }

    x = arith_seq_exclude_end_p(self);

    if (FIXNUM_P(b) && NIL_P(e) && FIXNUM_P(s)) {
        long i = FIX2LONG(b), unit = FIX2LONG(s);
        ary = rb_ary_new_capa(n);
        while (n > 0 && FIXABLE(i)) {
            rb_ary_push(ary, LONG2FIX(i));
            i += unit;  // FIXABLE + FIXABLE never overflow;
            --n;
        }
        if (n > 0) {
            b = LONG2NUM(i);
            while (n > 0) {
                rb_ary_push(ary, b);
                b = rb_big_plus(b, s);
                --n;
            }
        }
        return ary;
    }
    else if (FIXNUM_P(b) && FIXNUM_P(e) && FIXNUM_P(s)) {
        long i = FIX2LONG(b);
        long end = FIX2LONG(e);
        long unit = FIX2LONG(s);
        long len;

        if (unit >= 0) {
            if (!x) end += 1;

            len = end - i;
            if (len < 0) len = 0;
            ary = rb_ary_new_capa((n < len) ? n : len);
            while (n > 0 && i < end) {
                rb_ary_push(ary, LONG2FIX(i));
                if (i + unit < i) break;
                i += unit;
                --n;
            }
        }
        else {
            if (!x) end -= 1;

            len = i - end;
            if (len < 0) len = 0;
            ary = rb_ary_new_capa((n < len) ? n : len);
            while (n > 0 && i > end) {
                rb_ary_push(ary, LONG2FIX(i));
                if (i + unit > i) break;
                i += unit;
                --n;
            }
        }
        return ary;
    }
    else if (RB_FLOAT_TYPE_P(b) || RB_FLOAT_TYPE_P(e) || RB_FLOAT_TYPE_P(s)) {
        /* generate values like ruby_float_step */

        double unit = NUM2DBL(s);
        double beg = NUM2DBL(b);
        double end = NIL_P(e) ? (unit < 0 ? -1 : 1)*HUGE_VAL : NUM2DBL(e);
        double len = ruby_float_step_size(beg, end, unit, x);
        long i;

        if (n > len)
            n = (long)len;

        if (isinf(unit)) {
            if (len > 0) {
                ary = rb_ary_new_capa(1);
                rb_ary_push(ary, DBL2NUM(beg));
            }
            else {
                ary = rb_ary_new_capa(0);
            }
        }
        else if (unit == 0) {
            VALUE val = DBL2NUM(beg);
            ary = rb_ary_new_capa(n);
            for (i = 0; i < len; ++i) {
                rb_ary_push(ary, val);
            }
        }
        else {
            ary = rb_ary_new_capa(n);
            for (i = 0; i < n; ++i) {
                double d = i*unit+beg;
                if (unit >= 0 ? end < d : d < end) d = end;
                rb_ary_push(ary, DBL2NUM(d));
            }
        }

        return ary;
    }

    return rb_call_super(argc, argv);
}

#hashInteger

Compute a hash-value for this arithmetic sequence. Two arithmetic sequences with same begin, end, step, and exclude_end? values will generate the same hash-value.

See also Object#hash.

Returns:


3847
3848
3849
3850
3851
3852
3853
3854
3855
3856
3857
3858
3859
3860
3861
3862
3863
# File 'enumerator.c', line 3847

static VALUE
arith_seq_hash(VALUE self)
{
    st_index_t hash;
    VALUE v;

    hash = rb_hash_start(arith_seq_exclude_end_p(self));
    v = rb_hash(arith_seq_begin(self));
    hash = rb_hash_uint(hash, NUM2LONG(v));
    v = rb_hash(arith_seq_end(self));
    hash = rb_hash_uint(hash, NUM2LONG(v));
    v = rb_hash(arith_seq_step(self));
    hash = rb_hash_uint(hash, NUM2LONG(v));
    hash = rb_hash_end(hash);

    return ST2FIX(hash);
}

#inspectString

Convert this arithmetic sequence to a printable form.

Returns:


3747
3748
3749
3750
3751
3752
3753
3754
3755
3756
3757
3758
3759
3760
3761
3762
3763
3764
3765
3766
3767
3768
3769
3770
3771
3772
3773
3774
3775
3776
3777
3778
3779
3780
3781
3782
3783
3784
3785
3786
3787
3788
3789
3790
3791
3792
3793
3794
3795
3796
3797
3798
3799
3800
3801
3802
# File 'enumerator.c', line 3747

static VALUE
arith_seq_inspect(VALUE self)
{
    struct enumerator *e;
    VALUE eobj, str, eargs;
    int range_p;

    TypedData_Get_Struct(self, struct enumerator, &enumerator_data_type, e);

    eobj = rb_attr_get(self, id_receiver);
    if (NIL_P(eobj)) {
        eobj = e->obj;
    }

    range_p = RTEST(rb_obj_is_kind_of(eobj, rb_cRange));
    str = rb_sprintf("(%s%"PRIsVALUE"%s.", range_p ? "(" : "", eobj, range_p ? ")" : "");

    rb_str_buf_append(str, rb_id2str(e->meth));

    eargs = rb_attr_get(eobj, id_arguments);
    if (NIL_P(eargs)) {
        eargs = e->args;
    }
    if (eargs != Qfalse) {
        long argc = RARRAY_LEN(eargs);
        const VALUE *argv = RARRAY_CONST_PTR(eargs); /* WB: no new reference */

        if (argc > 0) {
            VALUE kwds = Qnil;

            rb_str_buf_cat2(str, "(");

            if (RB_TYPE_P(argv[argc-1], T_HASH)) {
                int all_key = TRUE;
                rb_hash_foreach(argv[argc-1], key_symbol_p, (VALUE)&all_key);
                if (all_key) kwds = argv[--argc];
            }

            while (argc--) {
                VALUE arg = *argv++;

                rb_str_append(str, rb_inspect(arg));
                rb_str_buf_cat2(str, ", ");
            }
            if (!NIL_P(kwds)) {
                rb_hash_foreach(kwds, kwd_append, str);
            }
            rb_str_set_len(str, RSTRING_LEN(str)-2); /* drop the last ", " */
            rb_str_buf_cat2(str, ")");
        }
    }

    rb_str_buf_cat2(str, ")");

    return str;
}

#lastNumeric? #last(n) ⇒ Array

Returns the last number in this arithmetic sequence, or an array of the last n elements.

Overloads:


3678
3679
3680
3681
3682
3683
3684
3685
3686
3687
3688
3689
3690
3691
3692
3693
3694
3695
3696
3697
3698
3699
3700
3701
3702
3703
3704
3705
3706
3707
3708
3709
3710
3711
3712
3713
3714
3715
3716
3717
3718
3719
3720
3721
3722
3723
3724
3725
3726
3727
3728
3729
3730
3731
3732
3733
3734
3735
3736
3737
3738
3739
# File 'enumerator.c', line 3678

static VALUE
arith_seq_last(int argc, VALUE *argv, VALUE self)
{
    VALUE b, e, s, len_1, len, last, nv, ary;
    int last_is_adjusted;
    long n;

    e = arith_seq_end(self);
    if (NIL_P(e)) {
        rb_raise(rb_eRangeError,
                 "cannot get the last element of endless arithmetic sequence");
    }

    b = arith_seq_begin(self);
    s = arith_seq_step(self);

    len_1 = num_idiv(num_minus(e, b), s);
    if (rb_num_negative_int_p(len_1)) {
        if (argc == 0) {
            return Qnil;
        }
        return rb_ary_new_capa(0);
    }

    last = num_plus(b, num_mul(s, len_1));
    if ((last_is_adjusted = arith_seq_exclude_end_p(self) && rb_equal(last, e))) {
        last = num_minus(last, s);
    }

    if (argc == 0) {
        return last;
    }

    if (last_is_adjusted) {
        len = len_1;
    }
    else {
        len = rb_int_plus(len_1, INT2FIX(1));
    }

    rb_scan_args(argc, argv, "1", &nv);
    if (!RB_INTEGER_TYPE_P(nv)) {
        nv = rb_to_int(nv);
    }
    if (RTEST(rb_int_gt(nv, len))) {
        nv = len;
    }
    n = NUM2LONG(nv);
    if (n < 0) {
        rb_raise(rb_eArgError, "negative array size");
    }

    ary = rb_ary_new_capa(n);
    b = rb_int_minus(last, rb_int_mul(s, nv));
    while (n) {
        b = rb_int_plus(b, s);
        rb_ary_push(ary, b);
        --n;
    }

    return ary;
}

#sizeNumeric?

Returns the number of elements in this arithmetic sequence if it is a finite sequence. Otherwise, returns nil.

Returns:


3942
3943
3944
3945
3946
3947
3948
3949
3950
3951
3952
3953
3954
3955
3956
3957
3958
3959
3960
3961
3962
3963
3964
3965
3966
3967
3968
3969
3970
3971
3972
3973
3974
3975
3976
3977
3978
3979
3980
3981
3982
3983
3984
3985
3986
3987
3988
3989
3990
3991
3992
3993
3994
3995
3996
3997
3998
3999
4000
# File 'enumerator.c', line 3942

static VALUE
arith_seq_size(VALUE self)
{
    VALUE b, e, s, len_1, len, last;
    int x;

    b = arith_seq_begin(self);
    e = arith_seq_end(self);
    s = arith_seq_step(self);
    x = arith_seq_exclude_end_p(self);

    if (RB_FLOAT_TYPE_P(b) || RB_FLOAT_TYPE_P(e) || RB_FLOAT_TYPE_P(s)) {
        double ee, n;

        if (NIL_P(e)) {
            if (rb_num_negative_int_p(s)) {
                ee = -HUGE_VAL;
            }
            else {
                ee = HUGE_VAL;
            }
        }
        else {
            ee = NUM2DBL(e);
        }

        n = ruby_float_step_size(NUM2DBL(b), ee, NUM2DBL(s), x);
        if (isinf(n)) return DBL2NUM(n);
        if (POSFIXABLE(n)) return LONG2FIX((long)n);
        return rb_dbl2big(n);
    }

    if (NIL_P(e)) {
        return DBL2NUM(HUGE_VAL);
    }

    if (!rb_obj_is_kind_of(s, rb_cNumeric)) {
        s = rb_to_int(s);
    }

    if (rb_equal(s, INT2FIX(0))) {
        return DBL2NUM(HUGE_VAL);
    }

    len_1 = rb_int_idiv(rb_int_minus(e, b), s);
    if (rb_num_negative_int_p(len_1)) {
        return INT2FIX(0);
    }

    last = rb_int_plus(b, rb_int_mul(s, len_1));
    if (x && rb_equal(last, e)) {
        len = len_1;
    }
    else {
        len = rb_int_plus(len_1, INT2FIX(1));
    }

    return len;
}

#stepObject