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Enumerator::ArithmeticSequence

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.

Public Instance Methods

aseq == obj → true or false click to toggle source

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

 
               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;
}
            
aseq == obj → true or false click to toggle source

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

 
               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;
}
            
begin() click to toggle source
 
               inline VALUE
arith_seq_begin(VALUE self)
{
    return rb_ivar_get(self, id_begin);
}
            
each {|i| block } → aseq click to toggle source
each → aseq
 
               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 = rb_int_idiv(rb_int_minus(e, c), s);
    last = rb_int_plus(c, rb_int_mul(s, len_1));
    if (x && rb_equal(last, e)) {
        last = rb_int_minus(last, s);
    }

    if (rb_num_negative_int_p(s)) {
        while (RTEST(rb_int_ge(c, last))) {
            rb_yield(c);
            c = rb_int_plus(c, s);
        }
    }
    else {
        while (RTEST(rb_int_ge(last, c))) {
            rb_yield(c);
            c = rb_int_plus(c, s);
        }
    }

    return self;
}
            
end() click to toggle source
 
               inline VALUE
arith_seq_end(VALUE self)
{
    return rb_ivar_get(self, id_end);
}
            
aseq == obj → true or false click to toggle source

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

 
               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?() click to toggle source
 
               inline VALUE
arith_seq_exclude_end(VALUE self)
{
    return rb_ivar_get(self, id_exclude_end);
}
            
first → num or nil click to toggle source
first(n) → an_array

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

 
               static VALUE
arith_seq_first(int argc, VALUE *argv, VALUE self)
{
    VALUE b, e, s, len_1;

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

    if (!NIL_P(e)) {
        len_1 = rb_int_idiv(rb_int_minus(e, b), s);
        if (rb_num_negative_int_p(len_1)) {
            if (argc == 0) {
                return Qnil;
            }
            return rb_ary_new_capa(0);
        }
    }

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

    /* TODO: optimization */

    return rb_call_super(argc, argv);
}
            
hash → integer click to toggle source

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.

 
               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 LONG2FIX(hash);
}
            
inspect → string click to toggle source

Convert this arithmetic sequence to a printable form.

 
               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, ", ");
                OBJ_INFECT(str, arg);
            }
            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;
}
            
last → num or nil click to toggle source
last(n) → an_array

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

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

    last = rb_int_plus(b, rb_int_mul(s, len_1));
    if ((last_is_adjusted = arith_seq_exclude_end_p(self) && rb_equal(last, e))) {
        last = rb_int_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;
}
            
size → num or nil click to toggle source

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

 
               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 = arith_seq_float_step_size(NUM2DBL(b), ee, NUM2DBL(s), x);
        if (isinf(n)) return DBL2NUM(n);
        if (POSFIXABLE(n)) return LONG2FIX(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;
}
            
step() click to toggle source
 
               inline VALUE
arith_seq_step(VALUE self)
{
    return rb_ivar_get(self, id_step);
}