Re: Most efficient way to recognize a line by its first (up to) three characters
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- Subject: Re: Most efficient way to recognize a line by its first (up to) three characters
- From: Luiz Henrique de Figueiredo <lhf@...>
- Date: 2014年3月11日 15:13:46 -0300
> local prefix, info = line:sub(1,3), line:sub(4)
> if prefix == "abc" then
> -- do something
> elseif prefix == "123" then
> -- do something else
> elseif ...
Consider this scheme instead of a chain of ifs:
local handlers={
["abc"]=function (prefix,info) ... end,
["123"]=function (prefix,info) ... end,
}
local badprefix=function (prefix,info) error("cannot handle "..prefix) end
while true do
local prefix, info = line:sub(1,3), line:sub(4)
local h = handlers[prefix] or badprefix
h(prefix,info)
end