Sha256: 6575f906eeb476bc67d52ce72da63c38efc7134f9db40c644dd3d84c38d9c8f2
Contents?: true
Size: 774 Bytes
Versions: 10
Compression:
Stored size: 774 Bytes
Contents
class Hash
# Create a "true" inverse hash by storing mutliple values in Arrays.
#
# h = {"a"=>3, "b"=>3, "c"=>3, "d"=>2, "e"=>9, "f"=>3, "g"=>9}
#
# h.invert #=> {2=>"d", 3=>"f", 9=>"g"}
# h.inverse #=> {2=>"d", 3=>["f", "c", "b", "a"], 9=>["g", "e"]}
# h.inverse.inverse #=> {"a"=>3, "b"=>3, "c"=>3, "d"=>2, "e"=>9, "f"=>3, "g"=>9}
#
# Of course the inverse of the inverse should be the same.
#
# (h.inverse.inverse == h) #=> true
#
# CREDIT: Tilo Sloboda
def inverse
i = Hash.new
self.each_pair{ |k,v|
if (Array === v)
v.each{ |x| i[x] = ( i.has_key?(x) ? [k,i[x]].flatten : k ) }
else
i[v] = ( i.has_key?(v) ? [k,i[v]].flatten : k )
end
}
return i
end
end
Version data entries
10 entries across 9 versions & 2 rubygems