Class: Range

Inherits:
Object show all
Includes:
ActiveSupport::CompareWithRange, ActiveSupport::RangeWithFormat
Defined in:
lib/active_support/core_ext/enumerable.rb,
lib/active_support/core_ext/range/sole.rb,
lib/active_support/core_ext/object/json.rb,
lib/active_support/core_ext/range/overlap.rb

Overview

:nodoc:

Constant Summary

Constants included from ActiveSupport::RangeWithFormat

ActiveSupport::RangeWithFormat::RANGE_FORMATS

Instance Method Summary collapse

Methods included from ActiveSupport::RangeWithFormat

#to_fs

Methods included from ActiveSupport::CompareWithRange

#===, #include?

Instance Method Details

#as_json(options = nil) ⇒ Object

:nodoc:



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# File 'lib/active_support/core_ext/object/json.rb', line 158

def as_json(options = nil) # :nodoc:
  to_s
end

#overlap?(other) ⇒ Boolean Also known as: overlaps?

Compare two ranges and see if they overlap each other

(1..5).overlap?(4..6) # => true
(1..5).overlap?(7..9) # => false

Returns:

  • (Boolean)

Raises:

  • (TypeError) 


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# File 'lib/active_support/core_ext/range/overlap.rb', line 8

def overlap?(other)
  raise TypeError unless other.is_a? Range

  self_begin = self.begin
  other_end = other.end
  other_excl = other.exclude_end?

  return false if _empty_range?(self_begin, other_end, other_excl)

  other_begin = other.begin
  self_end = self.end
  self_excl = self.exclude_end?

  return false if _empty_range?(other_begin, self_end, self_excl)
  return true if self_begin == other_begin

  return false if _empty_range?(self_begin, self_end, self_excl)
  return false if _empty_range?(other_begin, other_end, other_excl)

  true
end

#sole ⇒ Object

Returns the sole item in the range. If there are no items, or more than one item, raises Enumerable::SoleItemExpectedError.

(1..1).sole   # => 1
(2..1).sole   # => Enumerable::SoleItemExpectedError: no item found
(..1).sole    # => Enumerable::SoleItemExpectedError: infinite range cannot represent a sole item



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# File 'lib/active_support/core_ext/range/sole.rb', line 10

def sole
  if self.begin.nil? || self.end.nil?
    raise ActiveSupport::EnumerableCoreExt::SoleItemExpectedError, "infinite range '#{inspect}' cannot represent a sole item"
  end

  super
end

#sum(initial_value = 0) ⇒ Object

Optimize range sum to use arithmetic progression if a block is not given and we have a range of numeric values.



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# File 'lib/active_support/core_ext/enumerable.rb', line 253

def sum(initial_value = 0)
  if block_given? || !(first.is_a?(Integer) && last.is_a?(Integer))
    super
  else
    actual_last = exclude_end? ? (last - 1) : last
    if actual_last >= first
      sum = initial_value || 0
      sum + (actual_last - first + 1) * (actual_last + first) / 2
    else
      initial_value || 0
    end
  end
end