Sha256: f5dc00814267028139ab7b50fe395f8681675ca89adb4a35b6babc83055d6872
Contents?: true
Size: 976 Bytes
Versions: 4
Compression:
Stored size: 976 Bytes
Contents
unless (RUBY_VERSION[0,3] == '1.9')
module Enumerable
# Enumerable#one? returns +true+ if and only if <em>exactly one</em>
# element in the collection satisfies the given predicate.
#
# If no predicate is provided, Enumerable#one? returns +true+ if
# and only if <em>exactly one</em> element has a true value
# (i.e. not +nil+ or +false+).
#
# [].one? # false
# [nil].one? # false
# [5].one? # true
# [5,8,9].one? # false
# (1...10).one? { |n| n == 5 } # true
# (1...10).one? { |n| n < 5 } # false
#
# CREDIT: Gavin Sinclair
def one? # :yield: e
matches = 0
if block_given?
self.each do |e|
if yield(e)
matches += 1
return false if matches > 1
end
end
return (matches == 1)
else
one? { |e| e }
end
end
end
end
Version data entries
4 entries across 4 versions & 1 rubygems