# Class: Range

Inherits:
Object
show all
Includes:
Enumerable
Defined in:
range.c

## Overview

A Range represents an interval—a set of values with a beginning and an end. Ranges may be constructed using the s`..`e and s`...`e literals, or with Range::new. Ranges constructed using `..` run from the beginning to the end inclusively. Those created using `...` exclude the end value. When used as an iterator, ranges return each value in the sequence.

``````(-1..-5).to_a      #=> []
(-5..-1).to_a      #=> [-5, -4, -3, -2, -1]
('a'..'e').to_a    #=> ["a", "b", "c", "d", "e"]
('a'...'e').to_a   #=> ["a", "b", "c", "d"]
``````

## Beginless/Endless Ranges

A “beginless range” and “endless range” represents a semi-infinite range. Literal notation for a beginless range is:

``````(..1)
# or
(...1)
``````

Literal notation for an endless range is:

``````(1..)
# or similarly
(1...)
``````

Which is equivalent to

``````(1..nil)  # or similarly (1...nil)
Range.new(1, nil) # or Range.new(1, nil, true)
``````

Beginless/endless ranges are useful, for example, for idiomatic slicing of arrays:

``````[1, 2, 3, 4, 5][...2]   # => [1, 2]
[1, 2, 3, 4, 5][2...]   # => [3, 4, 5]
``````

Some implementation details:

• `begin` of beginless range and `end` of endless range are `nil`;

• `each` of beginless range raises an exception;

• `each` of endless range enumerates infinite sequence (may be useful in combination with Enumerable#take_while or similar methods);

• `(1..)` and `(1...)` are not equal, although technically representing the same sequence.

## Custom Objects in Ranges

Ranges can be constructed using any objects that can be compared using the `<=>` operator. Methods that treat the range as a sequence (#each and methods inherited from Enumerable) expect the begin object to implement a `succ` method to return the next object in sequence. The #step and #include? methods require the begin object to implement `succ` or to be numeric.

In the `Xs` class below both `<=>` and `succ` are implemented so `Xs` can be used to construct ranges. Note that the Comparable module is included so the `==` method is defined in terms of `<=>`.

``````class Xs                # represent a string of 'x's
include Comparable
attr :length
def initialize(n)
@length = n
end
def succ
Xs.new(@length + 1)
end
def <=>(other)
@length <=> other.length
end
def to_s
sprintf "%2d #{inspect}", @length
end
def inspect
'x' * @length
end
end
``````

An example of using `Xs` to construct a range:

``````r = Xs.new(3)..Xs.new(6)   #=> xxx..xxxxxx
r.to_a                     #=> [xxx, xxxx, xxxxx, xxxxxx]
r.member?(Xs.new(5))       #=> true
``````

## Instance Method Summary collapse

• Iterates over the range, passing each `n`th element to the block.

• Returns `true` only if `obj` is a Range, has equivalent begin and end items (by comparing them with `==`), and has the same #exclude_end? setting as the range.

• Returns `true` if `obj` is between begin and end of range, `false` otherwise (same as #cover?).

• Returns the object that defines the beginning of the range.

• By using binary search, finds a value in range which meets the given condition in O(log n) where n is the size of the range.

• Identical to Enumerable#count, except it returns Infinity for endless ranges.

• Returns `true` if `obj` is between the begin and end of the range.

• Iterates over the elements of range, passing each in turn to the block.

• Returns the object that defines the end of the range.

• Returns an array containing the items in the range.

• Returns `true` only if `obj` is a Range, has equivalent begin and end items (by comparing them with `eql?`), and has the same #exclude_end? setting as the range.

• Returns `true` if the range excludes its end value.

• Returns the first object in the range, or an array of the first `n` elements.

• Compute a hash-code for this range.

• Returns `true` if `obj` is an element of the range, `false` otherwise.

• constructor

Constructs a range using the given `begin` and `end`.

• :nodoc:.

• Convert this range object to a printable form (using #inspect to convert the begin and end objects).

• Returns the last object in the range, or an array of the last `n` elements.

• Returns the maximum value in the range.

• Returns `true` if `obj` is an element of the range, `false` otherwise.

• Returns the minimum value in the range.

• Returns a two element array which contains the minimum and the maximum value in the range.

• Returns the number of elements in the range.

• Iterates over the range, passing each `n`th element to the block.

• Returns an array containing the items in the range.

• Convert this range object to a printable form (using #to_s to convert the begin and end objects).

## Constructor Details

### #new ⇒ Object

Constructs a range using the given `begin` and `end`. If the `exclude_end` parameter is omitted or is `false`, the range will include the end object; otherwise, it will be excluded.

 ``` 89 90 91 92 93 94 95 96 97 98``` ```# File 'range.c', line 89 static VALUE range_initialize(int argc, VALUE *argv, VALUE range) { VALUE beg, end, flags; rb_scan_args(argc, argv, "21", &beg, &end, &flags); range_modify(range); range_init(range, beg, end, RBOOL(RTEST(flags))); return Qnil; }```

## Instance Method Details

### #step(n = 1) {|obj| ... } ⇒ Object #step(n = 1) ⇒ Object #step(n = 1) ⇒ Object #%(n) ⇒ Object #%(n) ⇒ Object

Iterates over the range, passing each `n`th element to the block. If begin and end are numeric, `n` is added for each iteration. Otherwise #step invokes #succ to iterate through range elements.

If no block is given, an enumerator is returned instead. Especially, the enumerator is an Enumerator::ArithmeticSequence if begin and end of the range are numeric.

``````range = Xs.new(1)..Xs.new(10)
range.step(2) {|x| puts x}
puts
range.step(3) {|x| puts x}
``````

produces:

`````` 1 x
3 xxx
5 xxxxx
7 xxxxxxx
9 xxxxxxxxx

1 x
4 xxxx
7 xxxxxxx
10 xxxxxxxxxx
``````

See Range for the definition of class Xs.

• #step(n = 1) {|obj| ... } ⇒ Object

Yields:

• (obj)
 ``` 508 509 510 511 512``` ```# File 'range.c', line 508 static VALUE range_percent_step(VALUE range, VALUE step) { return range_step(1, &step, range); }```

### #==(obj) ⇒ Boolean

Returns `true` only if `obj` is a Range, has equivalent begin and end items (by comparing them with `==`), and has the same #exclude_end? setting as the range.

``````(0..2) == (0..2)            #=> true
(0..2) == Range.new(0,2)    #=> true
(0..2) == (0...2)           #=> false
``````

Returns:

• (Boolean)
 ``` 154 155 156 157 158 159 160 161 162 163``` ```# File 'range.c', line 154 static VALUE range_eq(VALUE range, VALUE obj) { if (range == obj) return Qtrue; if (!rb_obj_is_kind_of(obj, rb_cRange)) return Qfalse; return rb_exec_recursive_paired(recursive_equal, range, obj, obj); }```

### #===(obj) ⇒ Boolean

Returns `true` if `obj` is between begin and end of range, `false` otherwise (same as #cover?). Conveniently, `===` is the comparison operator used by `case` statements.

``````case 79
when 1..50   then   puts "low"
when 51..75  then   puts "medium"
when 76..100 then   puts "high"
end
# Prints "high"

case "2.6.5"
when ..."2.4" then puts "EOL"
when "2.4"..."2.5" then puts "maintenance"
when "2.5"..."2.7" then puts "stable"
when "2.7".. then puts "upcoming"
end
# Prints "stable"
``````

Returns:

• (Boolean)
 ``` 1415 1416 1417 1418 1419 1420 1421``` ```# File 'range.c', line 1415 static VALUE range_eqq(VALUE range, VALUE val) { VALUE ret = range_include_internal(range, val, 1); if (ret != Qundef) return ret; return r_cover_p(range, RANGE_BEG(range), RANGE_END(range), val); }```

### #begin ⇒ Object

Returns the object that defines the beginning of the range.

``````(1..10).begin   #=> 1
``````

Returns:

 ``` 968 969 970 971 972``` ```# File 'range.c', line 968 static VALUE range_begin(VALUE range) { return RANGE_BEG(range); }```

### #bsearch {|obj| ... } ⇒ Object

By using binary search, finds a value in range which meets the given condition in O(log n) where n is the size of the range.

You can use this method in two use cases: a find-minimum mode and a find-any mode. In either case, the elements of the range must be monotone (or sorted) with respect to the block.

In find-minimum mode (this is a good choice for typical use case), the block must return true or false, and there must be a value x so that:

• the block returns false for any value which is less than x, and

• the block returns true for any value which is greater than or equal to x.

If x is within the range, this method returns the value x. Otherwise, it returns nil.

``````ary = [0, 4, 7, 10, 12]
(0...ary.size).bsearch {|i| ary[i] >= 4 } #=> 1
(0...ary.size).bsearch {|i| ary[i] >= 6 } #=> 2
(0...ary.size).bsearch {|i| ary[i] >= 8 } #=> 3
(0...ary.size).bsearch {|i| ary[i] >= 100 } #=> nil

(0.0...Float::INFINITY).bsearch {|x| Math.log(x) >= 0 } #=> 1.0
``````

In find-any mode (this behaves like libc’s bsearch(3)), the block must return a number, and there must be two values x and y (x <= y) so that:

• the block returns a positive number for v if v < x,

• the block returns zero for v if x <= v < y, and

• the block returns a negative number for v if y <= v.

This method returns any value which is within the intersection of the given range and x…y (if any). If there is no value that satisfies the condition, it returns nil.

``````ary = [0, 100, 100, 100, 200]
(0..4).bsearch {|i| 100 - ary[i] } #=> 1, 2 or 3
(0..4).bsearch {|i| 300 - ary[i] } #=> nil
(0..4).bsearch {|i|  50 - ary[i] } #=> nil
``````

You must not mix the two modes at a time; the block must always return either true/false, or always return a number. It is undefined which value is actually picked up at each iteration.

Yields:

• (obj)
 ``` 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757``` ```# File 'range.c', line 664 static VALUE range_bsearch(VALUE range) { VALUE beg, end, satisfied = Qnil; int smaller; /* Implementation notes: * Floats are handled by mapping them to 64 bits integers. * Apart from sign issues, floats and their 64 bits integer have the * same order, assuming they are represented as exponent followed * by the mantissa. This is true with or without implicit bit. * * Finding the average of two ints needs to be careful about * potential overflow (since float to long can use 64 bits) * as well as the fact that -1/2 can be 0 or -1 in C89. * * Note that -0.0 is mapped to the same int as 0.0 as we don't want * (-1...0.0).bsearch to yield -0.0. */ #define BSEARCH(conv) \ do { \ RETURN_ENUMERATOR(range, 0, 0); \ if (EXCL(range)) high--; \ org_high = high; \ while (low < high) { \ mid = ((high < 0) == (low < 0)) ? low + ((high - low) / 2) \ : (low < -high) ? -((-1 - low - high)/2 + 1) : (low + high) / 2; \ BSEARCH_CHECK(conv(mid)); \ if (smaller) { \ high = mid; \ } \ else { \ low = mid + 1; \ } \ } \ if (low == org_high) { \ BSEARCH_CHECK(conv(low)); \ if (!smaller) return Qnil; \ } \ return satisfied; \ } while (0) beg = RANGE_BEG(range); end = RANGE_END(range); if (FIXNUM_P(beg) && FIXNUM_P(end)) { long low = FIX2LONG(beg); long high = FIX2LONG(end); long mid, org_high; BSEARCH(INT2FIX); } #if SIZEOF_DOUBLE == 8 && defined(HAVE_INT64_T) else if (RB_TYPE_P(beg, T_FLOAT) || RB_TYPE_P(end, T_FLOAT)) { int64_t low = double_as_int64(NIL_P(beg) ? -HUGE_VAL : RFLOAT_VALUE(rb_Float(beg))); int64_t high = double_as_int64(NIL_P(end) ? HUGE_VAL : RFLOAT_VALUE(rb_Float(end))); int64_t mid, org_high; BSEARCH(int64_as_double_to_num); } #endif else if (is_integer_p(beg) && is_integer_p(end)) { RETURN_ENUMERATOR(range, 0, 0); return bsearch_integer_range(beg, end, EXCL(range)); } else if (is_integer_p(beg) && NIL_P(end)) { VALUE diff = LONG2FIX(1); RETURN_ENUMERATOR(range, 0, 0); while (1) { VALUE mid = rb_funcall(beg, '+', 1, diff); BSEARCH_CHECK(mid); if (smaller) { return bsearch_integer_range(beg, mid, 0); } diff = rb_funcall(diff, '*', 1, LONG2FIX(2)); } } else if (NIL_P(beg) && is_integer_p(end)) { VALUE diff = LONG2FIX(-1); RETURN_ENUMERATOR(range, 0, 0); while (1) { VALUE mid = rb_funcall(end, '+', 1, diff); BSEARCH_CHECK(mid); if (!smaller) { return bsearch_integer_range(mid, end, 0); } diff = rb_funcall(diff, '*', 1, LONG2FIX(2)); } } else { rb_raise(rb_eTypeError, "can't do binary search for %s", rb_obj_classname(beg)); } return range; }```

### #count ⇒ Integer #count(item) ⇒ Integer #count {|obj| ... } ⇒ Integer

Identical to Enumerable#count, except it returns Infinity for endless ranges.

 ``` 1640 1641 1642 1643 1644 1645 1646 1647 1648 1649 1650 1651 1652 1653 1654 1655 1656 1657 1658 1659 1660 1661 1662 1663 1664``` ```# File 'range.c', line 1640 static VALUE range_count(int argc, VALUE *argv, VALUE range) { if (argc != 0) { /* It is odd for instance (1...).count(0) to return Infinity. Just let * it loop. */ return rb_call_super(argc, argv); } else if (rb_block_given_p()) { /* Likewise it is odd for instance (1...).count {|x| x == 0 } to return * Infinity. Just let it loop. */ return rb_call_super(argc, argv); } else if (NIL_P(RANGE_END(range))) { /* We are confident that the answer is Infinity. */ return DBL2NUM(HUGE_VAL); } else if (NIL_P(RANGE_BEG(range))) { /* We are confident that the answer is Infinity. */ return DBL2NUM(HUGE_VAL); } else { return rb_call_super(argc, argv); } }```

### #cover?(obj) ⇒ Boolean #cover?(range) ⇒ Boolean

Returns `true` if `obj` is between the begin and end of the range.

This tests `begin <= obj <= end` when #exclude_end? is `false` and `begin <= obj < end` when #exclude_end? is `true`.

If called with a Range argument, returns `true` when the given range is covered by the receiver, by comparing the begin and end values. If the argument can be treated as a sequence, this method treats it that way. In the specific case of `(a..b).cover?(c...d)` with `a <= c && b < d`, the end of the sequence must be calculated, which may exhibit poor performance if `c` is non-numeric. Returns `false` if the begin value of the range is larger than the end value. Also returns `false` if one of the internal calls to `<=>` returns `nil` (indicating the objects are not comparable).

``````("a".."z").cover?("c")  #=> true
("a".."z").cover?("5")  #=> false
("a".."z").cover?("cc") #=> true
("a".."z").cover?(1)    #=> false
(1..5).cover?(2..3)     #=> true
(1..5).cover?(0..6)     #=> false
(1..5).cover?(1...6)    #=> true
``````

• #cover?(obj) ⇒ Boolean

Returns:

• (Boolean)
• #cover?(range) ⇒ Boolean

Returns:

• (Boolean)
 ``` 1526 1527 1528 1529 1530 1531 1532 1533 1534 1535 1536 1537 1538``` ```# File 'range.c', line 1526 static VALUE range_cover(VALUE range, VALUE val) { VALUE beg, end; beg = RANGE_BEG(range); end = RANGE_END(range); if (rb_obj_is_kind_of(val, rb_cRange)) { return RBOOL(r_cover_range_p(range, beg, end, val)); } return r_cover_p(range, beg, end, val); }```

### #each {|i| ... } ⇒ Object #each ⇒ Object

Iterates over the elements of range, passing each in turn to the block.

The `each` method can only be used if the begin object of the range supports the `succ` method. A TypeError is raised if the object does not have `succ` method defined (like Float).

If no block is given, an enumerator is returned instead.

``````(10..15).each {|n| print n, ' ' }
# prints: 10 11 12 13 14 15

(2.5..5).each {|n| print n, ' ' }
# raises: TypeError: can't iterate from Float
``````

• #each {|i| ... } ⇒ Object

Yields:

• (i)
 ``` 851 852 853 854 855 856 857 858 859 860 861 862 863 864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956 957``` ```# File 'range.c', line 851 static VALUE range_each(VALUE range) { VALUE beg, end; long i, lim; RETURN_SIZED_ENUMERATOR(range, 0, 0, range_enum_size); beg = RANGE_BEG(range); end = RANGE_END(range); if (FIXNUM_P(beg) && NIL_P(end)) { fixnum_endless: i = FIX2LONG(beg); while (FIXABLE(i)) { rb_yield(LONG2FIX(i++)); } beg = LONG2NUM(i); bignum_endless: for (;; beg = rb_big_plus(beg, INT2FIX(1))) rb_yield(beg); } else if (FIXNUM_P(beg) && FIXNUM_P(end)) { /* fixnums are special */ fixnum_loop: lim = FIX2LONG(end); if (!EXCL(range)) lim += 1; for (i = FIX2LONG(beg); i < lim; i++) { rb_yield(LONG2FIX(i)); } } else if (RB_INTEGER_TYPE_P(beg) && (NIL_P(end) || RB_INTEGER_TYPE_P(end))) { if (SPECIAL_CONST_P(end) || RBIGNUM_POSITIVE_P(end)) { /* end >= FIXNUM_MIN */ if (!FIXNUM_P(beg)) { if (RBIGNUM_NEGATIVE_P(beg)) { do { rb_yield(beg); } while (!FIXNUM_P(beg = rb_big_plus(beg, INT2FIX(1)))); if (NIL_P(end)) goto fixnum_endless; if (FIXNUM_P(end)) goto fixnum_loop; } else { if (NIL_P(end)) goto bignum_endless; if (FIXNUM_P(end)) return range; } } if (FIXNUM_P(beg)) { i = FIX2LONG(beg); do { rb_yield(LONG2FIX(i)); } while (POSFIXABLE(++i)); beg = LONG2NUM(i); } ASSUME(!FIXNUM_P(beg)); ASSUME(!SPECIAL_CONST_P(end)); } if (!FIXNUM_P(beg) && RBIGNUM_SIGN(beg) == RBIGNUM_SIGN(end)) { if (EXCL(range)) { while (rb_big_cmp(beg, end) == INT2FIX(-1)) { rb_yield(beg); beg = rb_big_plus(beg, INT2FIX(1)); } } else { VALUE c; while ((c = rb_big_cmp(beg, end)) != INT2FIX(1)) { rb_yield(beg); if (c == INT2FIX(0)) break; beg = rb_big_plus(beg, INT2FIX(1)); } } } } else if (SYMBOL_P(beg) && (NIL_P(end) || SYMBOL_P(end))) { /* symbols are special */ beg = rb_sym2str(beg); if (NIL_P(end)) { rb_str_upto_endless_each(beg, sym_each_i, 0); } else { rb_str_upto_each(beg, rb_sym2str(end), EXCL(range), sym_each_i, 0); } } else { VALUE tmp = rb_check_string_type(beg); if (!NIL_P(tmp)) { if (!NIL_P(end)) { rb_str_upto_each(tmp, end, EXCL(range), each_i, 0); } else { rb_str_upto_endless_each(tmp, each_i, 0); } } else { if (!discrete_object_p(beg)) { rb_raise(rb_eTypeError, "can't iterate from %s", rb_obj_classname(beg)); } if (!NIL_P(end)) range_each_func(range, each_i, 0); else for (;; beg = rb_funcallv(beg, id_succ, 0, 0)) rb_yield(beg); } } return range; }```

### #end ⇒ Object

Returns the object that defines the end of the range.

``````(1..10).end    #=> 10
(1...10).end   #=> 10
``````

Returns:

 ``` 986 987 988 989 990``` ```# File 'range.c', line 986 static VALUE range_end(VALUE range) { return RANGE_END(range); }```

### #to_a ⇒ Array #entries ⇒ Array

Returns an array containing the items in the range.

``````(1..7).to_a  #=> [1, 2, 3, 4, 5, 6, 7]
(1..).to_a   #=> RangeError: cannot convert endless range to an array
``````

 ``` 815 816 817 818 819 820 821 822``` ```# File 'range.c', line 815 static VALUE range_to_a(VALUE range) { if (NIL_P(RANGE_END(range))) { rb_raise(rb_eRangeError, "cannot convert endless range to an array"); } return rb_call_super(0, 0); }```

### #eql?(obj) ⇒ Boolean

Returns `true` only if `obj` is a Range, has equivalent begin and end items (by comparing them with `eql?`), and has the same #exclude_end? setting as the range.

``````(0..2).eql?(0..2)            #=> true
(0..2).eql?(Range.new(0,2))  #=> true
(0..2).eql?(0...2)           #=> false
``````

Returns:

• (Boolean)
 ``` 208 209 210 211 212 213 214 215 216``` ```# File 'range.c', line 208 static VALUE range_eql(VALUE range, VALUE obj) { if (range == obj) return Qtrue; if (!rb_obj_is_kind_of(obj, rb_cRange)) return Qfalse; return rb_exec_recursive_paired(recursive_eql, range, obj, obj); }```

### #exclude_end? ⇒ Boolean

Returns `true` if the range excludes its end value.

``````(1..5).exclude_end?     #=> false
(1...5).exclude_end?    #=> true
``````

Returns:

• (Boolean)
 ``` 119 120 121 122 123``` ```# File 'range.c', line 119 static VALUE range_exclude_end_p(VALUE range) { return EXCL(range) ? Qtrue : Qfalse; }```

### #first ⇒ Object #first(n) ⇒ Array

Returns the first object in the range, or an array of the first `n` elements.

``````(10..20).first     #=> 10
(10..20).first(3)  #=> [10, 11, 12]
``````

 ``` 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036``` ```# File 'range.c', line 1020 static VALUE range_first(int argc, VALUE *argv, VALUE range) { VALUE n, ary[2]; if (NIL_P(RANGE_BEG(range))) { rb_raise(rb_eRangeError, "cannot get the first element of beginless range"); } if (argc == 0) return RANGE_BEG(range); rb_scan_args(argc, argv, "1", &n); ary[0] = n; ary[1] = rb_ary_new2(NUM2LONG(n)); rb_block_call(range, idEach, 0, 0, first_i, (VALUE)ary); return ary[1]; }```

### #hash ⇒ Integer

Compute a hash-code for this range. Two ranges with equal begin and end points (using `eql?`), and the same #exclude_end? value will generate the same hash-code.

Returns:

 ``` 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244``` ```# File 'range.c', line 229 static VALUE range_hash(VALUE range) { st_index_t hash = EXCL(range); VALUE v; hash = rb_hash_start(hash); v = rb_hash(RANGE_BEG(range)); hash = rb_hash_uint(hash, NUM2LONG(v)); v = rb_hash(RANGE_END(range)); hash = rb_hash_uint(hash, NUM2LONG(v)); hash = rb_hash_uint(hash, EXCL(range) << 24); hash = rb_hash_end(hash); return ST2FIX(hash); }```

### #member?(obj) ⇒ Boolean #include?(obj) ⇒ Boolean

Returns `true` if `obj` is an element of the range, `false` otherwise.

``````("a".."z").include?("g")   #=> true
("a".."z").include?("A")   #=> false
("a".."z").include?("cc")  #=> false
``````

If you need to ensure `obj` is between `begin` and `end`, use #cover?

``````("a".."z").cover?("cc")  #=> true
``````

If begin and end are numeric, #include? behaves like #cover?

``````(1..3).include?(1.5) # => true
``````

• #member?(obj) ⇒ Boolean

Returns:

• (Boolean)
• #include?(obj) ⇒ Boolean

Returns:

• (Boolean)
 ``` 1445 1446 1447 1448 1449 1450 1451``` ```# File 'range.c', line 1445 static VALUE range_include(VALUE range, VALUE val) { VALUE ret = range_include_internal(range, val, 0); if (ret != Qundef) return ret; return rb_call_super(1, &val); }```

### #initialize_copy(orig) ⇒ Object

:nodoc:

 ``` 101 102 103 104 105 106 107``` ```# File 'range.c', line 101 static VALUE range_initialize_copy(VALUE range, VALUE orig) { range_modify(range); rb_struct_init_copy(range, orig); return range; }```

### #inspect ⇒ String

Convert this range object to a printable form (using #inspect to convert the begin and end objects).

Returns:

 ``` 1381 1382 1383 1384 1385``` ```# File 'range.c', line 1381 static VALUE range_inspect(VALUE range) { return rb_exec_recursive(inspect_range, range, 0); }```

### #last ⇒ Object #last(n) ⇒ Array

Returns the last object in the range, or an array of the last `n` elements.

Note that with no arguments `last` will return the object that defines the end of the range even if #exclude_end? is `true`.

``````(10..20).last      #=> 20
(10...20).last     #=> 20
(10..20).last(3)   #=> [18, 19, 20]
(10...20).last(3)  #=> [17, 18, 19]
``````

 ``` 1108 1109 1110 1111 1112 1113 1114 1115 1116 1117 1118 1119 1120 1121 1122 1123 1124 1125``` ```# File 'range.c', line 1108 static VALUE range_last(int argc, VALUE *argv, VALUE range) { VALUE b, e; if (NIL_P(RANGE_END(range))) { rb_raise(rb_eRangeError, "cannot get the last element of endless range"); } if (argc == 0) return RANGE_END(range); b = RANGE_BEG(range); e = RANGE_END(range); if (RB_INTEGER_TYPE_P(b) && RB_INTEGER_TYPE_P(e) && RB_LIKELY(rb_method_basic_definition_p(rb_cRange, idEach))) { return rb_int_range_last(argc, argv, range); } return rb_ary_last(argc, argv, rb_Array(range)); }```

### #max ⇒ Object #max {|a, b| ... } ⇒ Object #max(n) ⇒ Object #max(n) {|a, b| ... } ⇒ Object

Returns the maximum value in the range. Returns `nil` if the begin value of the range larger than the end value. Returns `nil` if the begin value of an exclusive range is equal to the end value.

Can be given an optional block to override the default comparison method `a <=> b`.

``````(10..20).max    #=> 20
``````

 ``` 1191 1192 1193 1194 1195 1196 1197 1198 1199 1200 1201 1202 1203 1204 1205 1206 1207 1208 1209 1210 1211 1212 1213 1214 1215 1216 1217 1218 1219 1220 1221 1222 1223 1224 1225 1226 1227 1228 1229``` ```# File 'range.c', line 1191 static VALUE range_max(int argc, VALUE *argv, VALUE range) { VALUE e = RANGE_END(range); int nm = FIXNUM_P(e) || rb_obj_is_kind_of(e, rb_cNumeric); if (NIL_P(RANGE_END(range))) { rb_raise(rb_eRangeError, "cannot get the maximum of endless range"); } if (rb_block_given_p() || (EXCL(range) && !nm) || argc) { if (NIL_P(RANGE_BEG(range))) { rb_raise(rb_eRangeError, "cannot get the maximum of beginless range with custom comparison method"); } return rb_call_super(argc, argv); } else { struct cmp_opt_data cmp_opt = { 0, 0 }; VALUE b = RANGE_BEG(range); int c = OPTIMIZED_CMP(b, e, cmp_opt); if (c > 0) return Qnil; if (EXCL(range)) { if (!RB_INTEGER_TYPE_P(e)) { rb_raise(rb_eTypeError, "cannot exclude non Integer end value"); } if (c == 0) return Qnil; if (!RB_INTEGER_TYPE_P(b)) { rb_raise(rb_eTypeError, "cannot exclude end value with non Integer begin value"); } if (FIXNUM_P(e)) { return LONG2NUM(FIX2LONG(e) - 1); } return rb_funcall(e, '-', 1, INT2FIX(1)); } return e; } }```

### #member?(obj) ⇒ Boolean #include?(obj) ⇒ Boolean

Returns `true` if `obj` is an element of the range, `false` otherwise.

``````("a".."z").include?("g")   #=> true
("a".."z").include?("A")   #=> false
("a".."z").include?("cc")  #=> false
``````

If you need to ensure `obj` is between `begin` and `end`, use #cover?

``````("a".."z").cover?("cc")  #=> true
``````

If begin and end are numeric, #include? behaves like #cover?

``````(1..3).include?(1.5) # => true
``````

• #member?(obj) ⇒ Boolean

Returns:

• (Boolean)
• #include?(obj) ⇒ Boolean

Returns:

• (Boolean)
 ``` 1445 1446 1447 1448 1449 1450 1451``` ```# File 'range.c', line 1445 static VALUE range_include(VALUE range, VALUE val) { VALUE ret = range_include_internal(range, val, 0); if (ret != Qundef) return ret; return rb_call_super(1, &val); }```

### #min ⇒ Object #min {|a, b| ... } ⇒ Object #min(n) ⇒ Array #min(n) {|a, b| ... } ⇒ Array

Returns the minimum value in the range. Returns `nil` if the begin value of the range is larger than the end value. Returns `nil` if the begin value of an exclusive range is equal to the end value.

Can be given an optional block to override the default comparison method `a <=> b`.

``````(10..20).min    #=> 10
``````

 ``` 1146 1147 1148 1149 1150 1151 1152 1153 1154 1155 1156 1157 1158 1159 1160 1161 1162 1163 1164 1165 1166 1167 1168 1169 1170 1171 1172``` ```# File 'range.c', line 1146 static VALUE range_min(int argc, VALUE *argv, VALUE range) { if (NIL_P(RANGE_BEG(range))) { rb_raise(rb_eRangeError, "cannot get the minimum of beginless range"); } if (rb_block_given_p()) { if (NIL_P(RANGE_END(range))) { rb_raise(rb_eRangeError, "cannot get the minimum of endless range with custom comparison method"); } return rb_call_super(argc, argv); } else if (argc != 0) { return range_first(argc, argv, range); } else { struct cmp_opt_data cmp_opt = { 0, 0 }; VALUE b = RANGE_BEG(range); VALUE e = RANGE_END(range); int c = NIL_P(e) ? -1 : OPTIMIZED_CMP(b, e, cmp_opt); if (c > 0 || (c == 0 && EXCL(range))) return Qnil; return b; } }```

### #minmax ⇒ Array #minmax {|a, b| ... } ⇒ Array

Returns a two element array which contains the minimum and the maximum value in the range.

Can be given an optional block to override the default comparison method `a <=> b`.

• #minmaxArray

Returns:

• #minmax {|a, b| ... } ⇒ Array

Yields:

• (a, b)

Returns:

 ``` 1243 1244 1245 1246 1247 1248 1249 1250``` ```# File 'range.c', line 1243 static VALUE range_minmax(VALUE range) { if (rb_block_given_p()) { return rb_call_super(0, NULL); } return rb_assoc_new(range_min(0, NULL, range), range_max(0, NULL, range)); }```

### #size ⇒ Numeric

Returns the number of elements in the range. Both the begin and the end of the Range must be Numeric, otherwise nil is returned.

``````(10..20).size    #=> 11
('a'..'z').size  #=> nil
(-Float::INFINITY..Float::INFINITY).size #=> Infinity
``````

Returns:

 ``` 785 786 787 788 789 790 791 792 793 794 795 796 797 798 799 800 801 802``` ```# File 'range.c', line 785 static VALUE range_size(VALUE range) { VALUE b = RANGE_BEG(range), e = RANGE_END(range); if (rb_obj_is_kind_of(b, rb_cNumeric)) { if (rb_obj_is_kind_of(e, rb_cNumeric)) { return ruby_num_interval_step_size(b, e, INT2FIX(1), EXCL(range)); } if (NIL_P(e)) { return DBL2NUM(HUGE_VAL); } } else if (NIL_P(b)) { return DBL2NUM(HUGE_VAL); } return Qnil; }```

### #step(n = 1) {|obj| ... } ⇒ Object #step(n = 1) ⇒ Object #step(n = 1) ⇒ Object #%(n) ⇒ Object #%(n) ⇒ Object

Iterates over the range, passing each `n`th element to the block. If begin and end are numeric, `n` is added for each iteration. Otherwise #step invokes #succ to iterate through range elements.

If no block is given, an enumerator is returned instead. Especially, the enumerator is an Enumerator::ArithmeticSequence if begin and end of the range are numeric.

``````range = Xs.new(1)..Xs.new(10)
range.step(2) {|x| puts x}
puts
range.step(3) {|x| puts x}
``````

produces:

`````` 1 x
3 xxx
5 xxxxx
7 xxxxxxx
9 xxxxxxxxx

1 x
4 xxxx
7 xxxxxxx
10 xxxxxxxxxx
``````

See Range for the definition of class Xs.

• #step(n = 1) {|obj| ... } ⇒ Object

Yields:

• (obj)
 ``` 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506``` ```# File 'range.c', line 400 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()) { 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); 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 */ VALUE iter[2]; iter[0] = INT2FIX(1); iter[1] = step; 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)) { VALUE iter[2]; b = tmp; iter[0] = INT2FIX(1); iter[1] = step; 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 { VALUE args[2]; if (!discrete_object_p(b)) { rb_raise(rb_eTypeError, "can't iterate from %s", rb_obj_classname(b)); } args[0] = INT2FIX(1); args[1] = step; range_each_func(range, step_i, (VALUE)args); } } return range; }```

### #to_a ⇒ Array #entries ⇒ Array

Returns an array containing the items in the range.

``````(1..7).to_a  #=> [1, 2, 3, 4, 5, 6, 7]
(1..).to_a   #=> RangeError: cannot convert endless range to an array
``````

 ``` 815 816 817 818 819 820 821 822``` ```# File 'range.c', line 815 static VALUE range_to_a(VALUE range) { if (NIL_P(RANGE_END(range))) { rb_raise(rb_eRangeError, "cannot convert endless range to an array"); } return rb_call_super(0, 0); }```
 ``` 1335 1336 1337 1338 1339 1340 1341 1342 1343 1344 1345 1346 1347``` ```# File 'range.c', line 1335 static VALUE range_to_s(VALUE range) { VALUE str, str2; str = rb_obj_as_string(RANGE_BEG(range)); str2 = rb_obj_as_string(RANGE_END(range)); str = rb_str_dup(str); rb_str_cat(str, "...", EXCL(range) ? 3 : 2); rb_str_append(str, str2); return str; }```