End of Life Ruby 3.2 has reached end of life and gets no more fixes. Switch to Ruby 4.0 →
instance method
Range#step
step(n = 1) {|element| ... } → self
step(n = 1) → enumerator
range.c
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static VALUE
range_step(int argc, VALUE *argv, VALUE range)
{
VALUE b, e, step, tmp;
b = RANGE_BEG(range);
e = RANGE_END(range);
step = (!rb_check_arity(argc, 0, 1) ? INT2FIX(1) : argv[0]);
if (!rb_block_given_p()) {
if (!rb_obj_is_kind_of(step, rb_cNumeric)) {
step = rb_to_int(step);
}
if (rb_equal(step, INT2FIX(0))) {
rb_raise(rb_eArgError, "step can't be 0");
}
const VALUE b_num_p = rb_obj_is_kind_of(b, rb_cNumeric);
const VALUE e_num_p = rb_obj_is_kind_of(e, rb_cNumeric);
if ((b_num_p && (NIL_P(e) || e_num_p)) || (NIL_P(b) && e_num_p)) {
return rb_arith_seq_new(range, ID2SYM(rb_frame_this_func()), argc, argv,
range_step_size, b, e, step, EXCL(range));
}
RETURN_SIZED_ENUMERATOR(range, argc, argv, range_step_size);
}
step = check_step_domain(step);
VALUE iter[2] = {INT2FIX(1), step};
if (FIXNUM_P(b) && NIL_P(e) && FIXNUM_P(step)) {
long i = FIX2LONG(b), unit = FIX2LONG(step);
do {
rb_yield(LONG2FIX(i));
i += unit; /* FIXABLE+FIXABLE never overflow */
} while (FIXABLE(i));
b = LONG2NUM(i);
for (;; b = rb_big_plus(b, step))
rb_yield(b);
}
else if (FIXNUM_P(b) && FIXNUM_P(e) && FIXNUM_P(step)) { /* fixnums are special */
long end = FIX2LONG(e);
long i, unit = FIX2LONG(step);
if (!EXCL(range))
end += 1;
i = FIX2LONG(b);
while (i < end) {
rb_yield(LONG2NUM(i));
if (i + unit < i) break;
i += unit;
}
}
else if (SYMBOL_P(b) && (NIL_P(e) || SYMBOL_P(e))) { /* symbols are special */
b = rb_sym2str(b);
if (NIL_P(e)) {
rb_str_upto_endless_each(b, sym_step_i, (VALUE)iter);
}
else {
rb_str_upto_each(b, rb_sym2str(e), EXCL(range), sym_step_i, (VALUE)iter);
}
}
else if (ruby_float_step(b, e, step, EXCL(range), TRUE)) {
/* done */
}
else if (rb_obj_is_kind_of(b, rb_cNumeric) ||
!NIL_P(rb_check_to_integer(b, "to_int")) ||
!NIL_P(rb_check_to_integer(e, "to_int"))) {
ID op = EXCL(range) ? '<' : idLE;
VALUE v = b;
int i = 0;
while (NIL_P(e) || RTEST(rb_funcall(v, op, 1, e))) {
rb_yield(v);
i++;
v = rb_funcall(b, '+', 1, rb_funcall(INT2NUM(i), '*', 1, step));
}
}
else {
tmp = rb_check_string_type(b);
if (!NIL_P(tmp)) {
b = tmp;
if (NIL_P(e)) {
rb_str_upto_endless_each(b, step_i, (VALUE)iter);
}
else {
rb_str_upto_each(b, e, EXCL(range), step_i, (VALUE)iter);
}
}
else {
if (!discrete_object_p(b)) {
rb_raise(rb_eTypeError, "can't iterate from %s",
rb_obj_classname(b));
}
range_each_func(range, step_i, (VALUE)iter);
}
}
return range;
}
Iterates over the elements of self.
With a block given and no argument, calls the block each element of the range; returns self:
Example
a = [] (1..5).step {|element| a.push(element) } # => 1..5 a # => [1, 2, 3, 4, 5] a = [] ('a'..'e').step {|element| a.push(element) } # => "a".."e" a # => ["a", "b", "c", "d", "e"]
With a block given and a positive integer argument n given, calls the block with element 0, element n, element 2n, and so on:
Example
a = [] (1..5).step(2) {|element| a.push(element) } # => 1..5 a # => [1, 3, 5] a = [] ('a'..'e').step(2) {|element| a.push(element) } # => "a".."e" a # => ["a", "c", "e"]
With no block given, returns an enumerator, which will be of class Enumerator::ArithmeticSequence if self is numeric; otherwise of class Enumerator:
Example
e = (1..5).step(2) # => ((1..5).step(2)) e.class # => Enumerator::ArithmeticSequence ('a'..'e').step # => #<Enumerator: ...>
Related: Range#%.