Re: comparing binary numbers with strings
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- Subject: Re: comparing binary numbers with strings
- From: Shmuel Zeigerman <shmuz@...>
- Date: 2007年10月28日 15:18:10 +0200
function compare(a,b)
a = tostring(tonumber(a) + tonumber(b))
return a:match"2"
end
As a funny extension of the above, here is a library whose functions
operate on "binary strings" (strings containing only 0's and 1's).
The operands must have lengths between 1 and 16.
-- bit.lua
local MINLEN, MAXLEN = 1, 16
function band(a,b)
a = tostring(tonumber(a) + tonumber(b))
return ( a:gsub("[12]", { ["1"]=0, ["2"]=1 }) )
end
function bor(a,b)
a = tostring(tonumber(a) + tonumber(b))
return ( a:gsub("2", "1") )
end
function bxor(a,b)
a = tostring(tonumber(a) + tonumber(b))
return ( a:gsub("2", "0") )
end
function bnot(a)
a = a:gsub("[01]", { ["0"]=1, ["1"]=0 })
return ("1"):rep(MAXLEN - #a) .. a
end
--
Shmuel