Sha256: ea3abc8cee7b70e748130aaf0301c47c18ed2b36d656b64dd91fa57e1b95a66b
Contents?: true
Size: 774 Bytes
Versions: 10
Compression:
Stored size: 774 Bytes
Contents
#--
# Thanks dave!
#++
class Proc
# Returns a new proc that is the functional
# compostion of two procs, in order.
#
# a = lambda { |x| x + 4 }
# b = lambda { |y| y / 2 }
#
# a.compose(b).call(4) #=> 6
# b.compase(a).call(4) #=> 4
#
def compose(g)
raise ArgumentError, "arity count mismatch" unless arity == g.arity
proc{ |*a| self[ *g[*a] ] }
end
end
# _____ _
# |_ _|__ ___| |_
# | |/ _ \/ __| __|
# | | __/\__ \ |_
# |_|\___||___/\__|
#
=begin test
require 'test/unit'
class TCProc < Test::Unit::TestCase
def test_compose
a = lambda { |x| x + 4 }
b = lambda { |y| y / 2 }
assert_equal( 6, (a.compose(b)).call(4) )
assert_equal( 4, (b.compose(a)).call(4) )
end
end
=end
Version data entries
10 entries across 10 versions & 1 rubygems