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"]

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

Methods included from Enumerable

#all?, #any?, #chunk, #collect, #collect_concat, #count, #cycle, #detect, #drop, #drop_while, #each_cons, #each_entry, #each_slice, #each_with_index, #each_with_object, #entries, #find, #find_all, #find_index, #flat_map, #grep, #group_by, #inject, #lazy, #map, #max_by, #min_by, #minmax, #minmax_by, #none?, #one?, #partition, #reduce, #reject, #reverse_each, #select, #slice_before, #sort, #sort_by, #take, #take_while, #to_a, #zip

Constructor Details

#new ⇒ Object

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



84
85
86
87
88
89
90
91
92
93
94
95
96
 
# File 'range.c', line 84

static VALUE
range_initialize(int argc, VALUE *argv, VALUE range)
{
    VALUE beg, end, flags;

    rb_scan_args(argc, argv, "21", &beg, &end, &flags);
    /* Ranges are immutable, so that they should be initialized only once. */
    if (RANGE_EXCL(range) != Qnil) {
	rb_name_error(idInitialize, "`initialize' called twice");
    }
    range_init(range, beg, end, RTEST(flags));
    return Qnil;
}

Instance Method Details

#==(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) 


145
146
147
148
149
150
151
152
153
154
 
# File 'range.c', line 145

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 an element of the range, false otherwise. Conveniently, === is the comparison operator used by case statements.

case 79
when 1..50   then   print "low\n"
when 51..75  then   print "medium\n"
when 76..100 then   print "high\n"
end

produces:

high

Returns:

  • (Boolean) 


1106
1107
1108
1109
1110
 
# File 'range.c', line 1106

static VALUE
range_eqq(VALUE range, VALUE val)
{
    return rb_funcall(range, rb_intern("include?"), 1, val);
}

#begin ⇒ Object

Returns the object that defines the beginning of the range.

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

Returns:



792
793
794
795
796
 
# File 'range.c', line 792

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 array.

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 array 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 i.

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) 


562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
 
# File 'range.c', line 562

static VALUE
range_bsearch(VALUE range)
{
    VALUE beg, end;
    int smaller, satisfied = 0;

    /* 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_CHECK(val) \
    do { \
	VALUE v = rb_yield(val); \
	if (FIXNUM_P(v)) { \
	    if (FIX2INT(v) == 0) return val; \
	    smaller = FIX2INT(v) < 0; \
	} \
	else if (v == Qtrue) { \
	    satisfied = 1; \
	    smaller = 1; \
	} \
	else if (v == Qfalse || v == Qnil) { \
	    smaller = 0; \
	} \
	else if (rb_obj_is_kind_of(v, rb_cNumeric)) { \
	    int cmp = rb_cmpint(rb_funcall(v, id_cmp, 1, INT2FIX(0)), v, INT2FIX(0)); \
	    if (!cmp) return val; \
	    smaller = cmp < 0; \
	} \
	else { \
	    rb_raise(rb_eTypeError, "wrong argument type %s" \
		" (must be numeric, true, false or nil)", \
		rb_obj_classname(v)); \
	} \
    } while (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; \
	} \
	if (!satisfied) return Qnil; \
	return conv(low); \
    } 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(RFLOAT_VALUE(rb_Float(beg)));
	int64_t high = double_as_int64(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)) {
	VALUE low = rb_to_int(beg);
	VALUE high = rb_to_int(end);
	VALUE mid, org_high;
	RETURN_ENUMERATOR(range, 0, 0);
	if (EXCL(range)) high = rb_funcall(high, '-', 1, INT2FIX(1));
	org_high = high;

	while (rb_cmpint(rb_funcall(low, id_cmp, 1, high), low, high) < 0) {
	    mid = rb_funcall(rb_funcall(high, '+', 1, low), id_div, 1, INT2FIX(2));
	    BSEARCH_CHECK(mid);
	    if (smaller) {
		high = mid;
	    }
	    else {
		low = rb_funcall(mid, '+', 1, INT2FIX(1));
	    }
	}
	if (rb_equal(low, org_high)) {
	    BSEARCH_CHECK(low);
	    if (!smaller) return Qnil;
	}
	if (!satisfied) return Qnil;
	return low;
    }
    else {
	rb_raise(rb_eTypeError, "can't do binary search for %s", rb_obj_classname(beg));
    }
    return range;
}

#cover?(obj) ⇒ 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.

("a".."z").cover?("c")    #=> true
("a".."z").cover?("5")    #=> false
("a".."z").cover?("cc")   #=> true

Returns:

  • (Boolean)

Returns:

  • (Boolean) 


1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
 
# File 'range.c', line 1190

static VALUE
range_cover(VALUE range, VALUE val)
{
    VALUE beg, end;

    beg = RANGE_BEG(range);
    end = RANGE_END(range);
    if (r_le(beg, val)) {
	if (EXCL(range)) {
	    if (r_lt(val, end))
		return Qtrue;
	}
	else {
	    if (r_le(val, end))
		return Qtrue;
	}
    }
    return Qfalse;
}

#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

Overloads:

  • #each {|i| ... } ⇒ Object

    Yields:

    • (i) 


735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
 
# File 'range.c', line 735

static VALUE
range_each(VALUE range)
{
    VALUE beg, end;

    RETURN_SIZED_ENUMERATOR(range, 0, 0, range_size);

    beg = RANGE_BEG(range);
    end = RANGE_END(range);

    if (FIXNUM_P(beg) && FIXNUM_P(end)) { /* fixnums are special */
	long lim = FIX2LONG(end);
	long i;

	if (!EXCL(range))
	    lim += 1;
	for (i = FIX2LONG(beg); i < lim; i++) {
	    rb_yield(LONG2FIX(i));
	}
    }
    else if (SYMBOL_P(beg) && SYMBOL_P(end)) { /* symbols are special */
	VALUE args[2];

	args[0] = rb_sym_to_s(end);
	args[1] = EXCL(range) ? Qtrue : Qfalse;
	rb_block_call(rb_sym_to_s(beg), rb_intern("upto"), 2, args, sym_each_i, 0);
    }
    else {
	VALUE tmp = rb_check_string_type(beg);

	if (!NIL_P(tmp)) {
	    VALUE args[2];

	    args[0] = end;
	    args[1] = EXCL(range) ? Qtrue : Qfalse;
	    rb_block_call(tmp, rb_intern("upto"), 2, args, rb_yield, 0);
	}
	else {
	    if (!discrete_object_p(beg)) {
		rb_raise(rb_eTypeError, "can't iterate from %s",
			 rb_obj_classname(beg));
	    }
	    range_each_func(range, each_i, NULL);
	}
    }
    return range;
}

#end ⇒ Object

Returns the object that defines the end of the range.

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

Returns:



810
811
812
813
814
 
# File 'range.c', line 810

static VALUE
range_end(VALUE range)
{
    return RANGE_END(range);
}

#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)

Returns:

  • (Boolean) 


213
214
215
216
217
218
219
220
221
 
# File 'range.c', line 213

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)

Returns:

  • (Boolean) 


110
111
112
113
114
 
# File 'range.c', line 110

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]

Overloads:



843
844
845
846
847
848
849
850
851
852
853
854
855
856
 
# File 'range.c', line 843

static VALUE
range_first(int argc, VALUE *argv, VALUE range)
{
    VALUE n, ary[2];

    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 ⇒ Fixnum

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:



251
252
253
254
255
 
# File 'range.c', line 251

static VALUE
range_hash(VALUE range)
{
    return rb_exec_recursive_outer(recursive_hash, range, 0);
}

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

Returns true if obj is an element of the range, false otherwise. If begin and end are numeric, comparison is done according to the magnitude of the values.

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

Overloads:

  • #member?(obj) ⇒ Boolean

    Returns:

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

    Returns:

    • (Boolean)

Returns:

  • (Boolean) 


1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
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 1127

static VALUE
range_include(VALUE range, VALUE val)
{
    VALUE beg = RANGE_BEG(range);
    VALUE end = RANGE_END(range);
    int nv = FIXNUM_P(beg) || FIXNUM_P(end) ||
	     rb_obj_is_kind_of(beg, rb_cNumeric) ||
	     rb_obj_is_kind_of(end, rb_cNumeric);

    if (nv ||
	!NIL_P(rb_check_to_integer(beg, "to_int")) ||
	!NIL_P(rb_check_to_integer(end, "to_int"))) {
	if (r_le(beg, val)) {
	    if (EXCL(range)) {
		if (r_lt(val, end))
		    return Qtrue;
	    }
	    else {
		if (r_le(val, end))
		    return Qtrue;
	    }
	}
	return Qfalse;
    }
    else if (RB_TYPE_P(beg, T_STRING) && RB_TYPE_P(end, T_STRING) &&
	     RSTRING_LEN(beg) == 1 && RSTRING_LEN(end) == 1) {
	if (NIL_P(val)) return Qfalse;
	if (RB_TYPE_P(val, T_STRING)) {
	    if (RSTRING_LEN(val) == 0 || RSTRING_LEN(val) > 1)
		return Qfalse;
	    else {
		char b = RSTRING_PTR(beg)[0];
		char e = RSTRING_PTR(end)[0];
		char v = RSTRING_PTR(val)[0];

		if (ISASCII(b) && ISASCII(e) && ISASCII(v)) {
		    if (b <= v && v < e) return Qtrue;
		    if (!EXCL(range) && v == e) return Qtrue;
		    return Qfalse;
		}
	    }
	}
    }
    /* TODO: ruby_frame->this_func = rb_intern("include?"); */
    return rb_call_super(1, &val);
}

#initialize_copy ⇒ Object

#inspect ⇒ String

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

Returns:



1081
1082
1083
1084
1085
 
# File 'range.c', line 1081

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]

Overloads:



876
877
878
879
880
881
 
# File 'range.c', line 876

static VALUE
range_last(int argc, VALUE *argv, VALUE range)
{
    if (argc == 0) return RANGE_END(range);
    return rb_ary_last(argc, argv, rb_Array(range));
}

#max ⇒ Object #max {|a, b| ... } ⇒ Object

Returns the maximum value in the range. Returns nil if the begin value of the range larger than the end value.

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

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

Overloads:



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
958
959
960
 
# File 'range.c', line 930

static VALUE
range_max(VALUE range)
{
    VALUE e = RANGE_END(range);
    int nm = FIXNUM_P(e) || rb_obj_is_kind_of(e, rb_cNumeric);

    if (rb_block_given_p() || (EXCL(range) && !nm)) {
	return rb_call_super(0, 0);
    }
    else {
	VALUE b = RANGE_BEG(range);
	int c = rb_cmpint(rb_funcall(b, id_cmp, 1, e), b, e);

	if (c > 0)
	    return Qnil;
	if (EXCL(range)) {
	    if (!FIXNUM_P(e) && !rb_obj_is_kind_of(e, rb_cInteger)) {
		rb_raise(rb_eTypeError, "cannot exclude non Integer end value");
	    }
	    if (c == 0) return Qnil;
	    if (!FIXNUM_P(b) && !rb_obj_is_kind_of(b,rb_cInteger)) {
		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. If begin and end are numeric, comparison is done according to the magnitude of the values.

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

Overloads:

  • #member?(obj) ⇒ Boolean

    Returns:

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

    Returns:

    • (Boolean)

Returns:

  • (Boolean) 


1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
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 1127

static VALUE
range_include(VALUE range, VALUE val)
{
    VALUE beg = RANGE_BEG(range);
    VALUE end = RANGE_END(range);
    int nv = FIXNUM_P(beg) || FIXNUM_P(end) ||
	     rb_obj_is_kind_of(beg, rb_cNumeric) ||
	     rb_obj_is_kind_of(end, rb_cNumeric);

    if (nv ||
	!NIL_P(rb_check_to_integer(beg, "to_int")) ||
	!NIL_P(rb_check_to_integer(end, "to_int"))) {
	if (r_le(beg, val)) {
	    if (EXCL(range)) {
		if (r_lt(val, end))
		    return Qtrue;
	    }
	    else {
		if (r_le(val, end))
		    return Qtrue;
	    }
	}
	return Qfalse;
    }
    else if (RB_TYPE_P(beg, T_STRING) && RB_TYPE_P(end, T_STRING) &&
	     RSTRING_LEN(beg) == 1 && RSTRING_LEN(end) == 1) {
	if (NIL_P(val)) return Qfalse;
	if (RB_TYPE_P(val, T_STRING)) {
	    if (RSTRING_LEN(val) == 0 || RSTRING_LEN(val) > 1)
		return Qfalse;
	    else {
		char b = RSTRING_PTR(beg)[0];
		char e = RSTRING_PTR(end)[0];
		char v = RSTRING_PTR(val)[0];

		if (ISASCII(b) && ISASCII(e) && ISASCII(v)) {
		    if (b <= v && v < e) return Qtrue;
		    if (!EXCL(range) && v == e) return Qtrue;
		    return Qfalse;
		}
	    }
	}
    }
    /* TODO: ruby_frame->this_func = rb_intern("include?"); */
    return rb_call_super(1, &val);
}

#min ⇒ Object #min {|a, b| ... } ⇒ Object

Returns the minimum value in the range. Returns nil if the begin value of the range is larger than the end value.

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

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

Overloads:



899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
 
# File 'range.c', line 899

static VALUE
range_min(VALUE range)
{
    if (rb_block_given_p()) {
	return rb_call_super(0, 0);
    }
    else {
	VALUE b = RANGE_BEG(range);
	VALUE e = RANGE_END(range);
	int c = rb_cmpint(rb_funcall(b, id_cmp, 1, e), b, e);

	if (c > 0 || (c == 0 && EXCL(range)))
	    return Qnil;
	return b;
    }
}

#size ⇒ Numeric

Returns the number of elements in the range.

(10..20).size    #=> 11

Returns:



704
705
706
707
708
709
710
711
712
 
# File 'range.c', line 704

static VALUE
range_size(VALUE range)
{
    VALUE b = RANGE_BEG(range), e = RANGE_END(range);
    if (rb_obj_is_kind_of(b, rb_cNumeric) && rb_obj_is_kind_of(e, rb_cNumeric)) {
	return num_interval_step_size(b, e, INT2FIX(1), EXCL(range));
    }
    return Qnil;
}

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

Iterates over the range, passing each nth 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.

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.

Overloads:

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

    Yields:

    • (obj) 


382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
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
 
# File 'range.c', line 382

static VALUE
range_step(int argc, VALUE *argv, VALUE range)
{
    VALUE b, e, step, tmp;

    RETURN_SIZED_ENUMERATOR(range, argc, argv, range_step_size);

    b = RANGE_BEG(range);
    e = RANGE_END(range);
    if (argc == 0) {
	step = INT2FIX(1);
    }
    else {
	rb_scan_args(argc, argv, "01", &step);
	if (!rb_obj_is_kind_of(step, rb_cNumeric)) {
	    step = rb_to_int(step);
	}
	if (rb_funcall(step, '<', 1, INT2FIX(0))) {
	    rb_raise(rb_eArgError, "step can't be negative");
	}
	else if (!rb_funcall(step, '>', 1, INT2FIX(0))) {
	    rb_raise(rb_eArgError, "step can't be 0");
	}
    }

    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) && SYMBOL_P(e)) { /* symbols are special */
	VALUE args[2], iter[2];

	args[0] = rb_sym_to_s(e);
	args[1] = EXCL(range) ? Qtrue : Qfalse;
	iter[0] = INT2FIX(1);
	iter[1] = step;
	rb_block_call(rb_sym_to_s(b), rb_intern("upto"), 2, args, sym_step_i, (VALUE)iter);
    }
    else if (ruby_float_step(b, e, step, EXCL(range))) {
	/* 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 (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 args[2], iter[2];

	    b = tmp;
	    args[0] = e;
	    args[1] = EXCL(range) ? Qtrue : Qfalse;
	    iter[0] = INT2FIX(1);
	    iter[1] = step;
	    rb_block_call(b, rb_intern("upto"), 2, args, 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, args);
	}
    }
    return range;
}

#to_s ⇒ String

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

Returns:



1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
 
# File 'range.c', line 1038

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);
    OBJ_INFECT(str, str2);

    return str;
}