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Delegates: Difference between revisions
→{{header|Lua}}
Thundergnat (talk | contribs) (Rename Perl 6 -> Raku, alphabetize, minor clean-up) |
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Line 1,388:
String3 == 'delegate implementation'
)).</lang>
=={{header|Lua}}==
<lang lua>local function Delegator()
return {
operation = function(self)
if (type(self.delegate)=="table") and (type(self.delegate.thing)=="function") then
return self.delegate:thing()
else
return "default implementation"
end
end
}
end
local function Delegate()
return {
thing = function(self)
return "delegate implementation"
end
}
end
local function NonDelegate(which)
if (which == 1) then return true -- boolean
elseif (which == 2) then return 12345 -- number
elseif (which == 3) then return "Hello" -- string
elseif (which == 4) then return function() end -- function
elseif (which == 5) then return { nothing = function(self) end } -- table (without "thing")
elseif (which == 6) then return coroutine.create(function() end) -- thread
elseif (which == 7) then return io.open("delegates.lua","r") -- userdata (if exists, or nil)
end
end
-- WITH NO (NIL) DELEGATE
local d = Delegator()
assert(d:operation() == "default implementation")
-- WITH A NON-DELEGATE
for i = 1, 7 do
d.delegate = NonDelegate(i)
assert(d:operation() == "default implementation")
end
-- WITH A PROPER DELEGATE
d.delegate = Delegate()
assert(d:operation() == "delegate implementation")
print("pass")</lang>
=={{header|M2000 Interpreter}}==
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