An Alternative Way to Refine A Class

[Lou Henry Alvarez]

This Jackbox feature showcases an alternative way to refine classes,
that also illustrates some additional uses of our modular
closures/injectors. For this to happen, we rely once again on our trusty
method #lets. Take a look at this example code:


# Injector declaration

StringExtensions = injector :StringExtensions do
def to_s
super + '++++'
end
end


# Jackbox Re-Classing

lets String do
include StringExtensions
end
str = String('boo')

assert(
str.to_s == 'boo++++'
)

assert(
String.new('bar).to_s == "bar"
)

For more details please visit:
http://blog.jackbox.us/2015/09/an-alternative-way-to-refine-class.html

--
Posted via http://www.ruby-forum.com/.

[Lou Henry Alvarez]

# Injector declaration

jack :StringRefinements do
lets String do # Our re-classing
with singleton_class do
def new *args, &code
super(*args, &code) + ' is a special string'
end
end
end
end

class OurClass
include StringRefinements()

def foo_bar
String('foo and bar')
end
end

c = OurClass.new
c.foo_bar.class.should == String
c.foo_bar.should == 'foo and bar is a special string'

StringRefinements do
String() do # Adding more stuff
def extra
:extra
end
end
end

c.foo_bar.should == 'foo and bar is a special string'
c.foo_bar.extra.should == :extra

SR = StringRefinements do
lets String do # New Version
def to_s
super + '****'
end
end
end

# c is still the same

c.foo_bar.should == 'foo and bar is a special string'
c.foo_bar.extra.should == :extra


class OurOtherClass
include SR # Another class application


def foo_bar
String('foo and bar')
end
end

d = OurOtherClass.new

d.foo_bar.to_s.should == 'foo and bar****'
expect{ d.extra }.to raise_error(NoMethodError)