RosettaCodeData/Task/Polymorphic-copy/Lua/polymorphic-copy.lua

17 lines
664 B
Lua

T = { name=function(s) return "T" end, tostring=function(s) return "I am a "..s:name() end }
function clone(s) local t={} for k,v in pairs(s) do t[k]=v end return t end
S1 = clone(T) S1.name=function(s) return "S1" end
function merge(s,t) for k,v in pairs(t) do s[k]=v end return s end
S2 = merge(clone(T), {name=function(s) return "S2" end})
function prototype(base,mixin) return merge(merge(clone(base),mixin),{prototype=base}) end
S3 = prototype(T, {name=function(s) return "S3" end})
print("T : "..T:tostring())
print("S1: " ..S1:tostring())
print("S2: " ..S2:tostring())
print("S3: " ..S3:tostring())
print("S3's parent: "..S3.prototype:tostring())