diff options
Diffstat (limited to 'lualibs-number.lua')
| -rw-r--r-- | lualibs-number.lua | 241 |
1 files changed, 157 insertions, 84 deletions
diff --git a/lualibs-number.lua b/lualibs-number.lua index a4dbe3b..001ca31 100644 --- a/lualibs-number.lua +++ b/lualibs-number.lua @@ -6,7 +6,8 @@ if not modules then modules = { } end modules ['l-number'] = { license = "see context related readme files" } --- this module will be replaced when we have the bit library +-- this module will be replaced when we have the bit library .. the number based sets +-- might go away local tostring, tonumber = tostring, tonumber local format, floor, match, rep = string.format, math.floor, string.match, string.rep @@ -16,10 +17,129 @@ local lpegmatch = lpeg.match number = number or { } local number = number --- a,b,c,d,e,f = number.toset(100101) +if bit32 then -- I wonder if this is faster + + local btest, bor = bit32.btest, bit32.bor + + function number.bit(p) + return 2 ^ (p - 1) -- 1-based indexing + end + + number.hasbit = btest + number.setbit = bor + + function number.setbit(x,p) -- why not bor? + return btest(x,p) and x or x + p + end + + function number.clearbit(x,p) + return btest(x,p) and x - p or x + end + +else + + -- http://ricilake.blogspot.com/2007/10/iterating-bits-in-lua.html + + function number.bit(p) + return 2 ^ (p - 1) -- 1-based indexing + end + + function number.hasbit(x, p) -- typical call: if hasbit(x, bit(3)) then ... + return x % (p + p) >= p + end + + function number.setbit(x, p) + return (x % (p + p) >= p) and x or x + p + end + + function number.clearbit(x, p) + return (x % (p + p) >= p) and x - p or x + end -function number.toset(n) - return match(tostring(n),"(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)") +end + +-- print(number.tobitstring(8)) +-- print(number.tobitstring(14)) +-- print(number.tobitstring(66)) +-- print(number.tobitstring(0x00)) +-- print(number.tobitstring(0xFF)) +-- print(number.tobitstring(46260767936,4)) + +if bit32 then + + local bextract = bit32.extract + + local t = { + "0", "0", "0", "0", "0", "0", "0", "0", + "0", "0", "0", "0", "0", "0", "0", "0", + "0", "0", "0", "0", "0", "0", "0", "0", + "0", "0", "0", "0", "0", "0", "0", "0", + } + + function number.tobitstring(b,m) + -- if really needed we can speed this one up + -- because small numbers need less extraction + local n = 32 + for i=0,31 do + local v = bextract(b,i) + local k = 32 - i + if v == 1 then + n = k + t[k] = "1" + else + t[k] = "0" + end + end + if m then + m = 33 - m * 8 + if m < 1 then + m = 1 + end + return concat(t,"",m) + elseif n < 8 then + return concat(t) + elseif n < 16 then + return concat(t,"",9) + elseif n < 24 then + return concat(t,"",17) + else + return concat(t,"",25) + end + end + +else + + function number.tobitstring(n,m) + if n > 0 then + local t = { } + while n > 0 do + insert(t,1,n % 2 > 0 and 1 or 0) + n = floor(n/2) + end + local nn = 8 - #t % 8 + if nn > 0 and nn < 8 then + for i=1,nn do + insert(t,1,0) + end + end + if m then + m = m * 8 - #t + if m > 0 then + insert(t,1,rep("0",m)) + end + end + return concat(t) + elseif m then + rep("00000000",m) + else + return "00000000" + end + end + +end + +function number.valid(str,default) + return tonumber(str) or default or nil end function number.toevenhex(n) @@ -31,104 +151,57 @@ function number.toevenhex(n) end end --- the lpeg way is slower on 8 digits, but faster on 4 digits, some 7.5% --- on +-- a,b,c,d,e,f = number.toset(100101) +-- +-- function number.toset(n) +-- return match(tostring(n),"(.?)(.?)(.?)(.?)(.?)(.?)(.?)(.?)") +-- end +-- +-- -- the lpeg way is slower on 8 digits, but faster on 4 digits, some 7.5% +-- -- on -- -- for i=1,1000000 do -- local a,b,c,d,e,f,g,h = number.toset(12345678) -- local a,b,c,d = number.toset(1234) -- local a,b,c = number.toset(123) +-- local a,b,c = number.toset("123") -- end --- --- of course dedicated "(.)(.)(.)(.)" matches are even faster -local one = lpeg.C(1-lpeg.S(''))^1 +local one = lpeg.C(1-lpeg.S('')/tonumber)^1 function number.toset(n) return lpegmatch(one,tostring(n)) end -function number.bits(n,zero) - local t, i = { }, (zero and 0) or 1 - while n > 0 do +-- function number.bits(n,zero) +-- local t, i = { }, (zero and 0) or 1 +-- while n > 0 do +-- local m = n % 2 +-- if m > 0 then +-- insert(t,1,i) +-- end +-- n = floor(n/2) +-- i = i + 1 +-- end +-- return t +-- end +-- +-- -- a bit faster + +local function bits(n,i,...) + if n > 0 then local m = n % 2 + local n = floor(n/2) if m > 0 then - insert(t,1,i) - end - n = floor(n/2) - i = i + 1 - end - return t -end - ---~ http://ricilake.blogspot.com/2007/10/iterating-bits-in-lua.html - -function number.bit(p) - return 2 ^ (p - 1) -- 1-based indexing -end - -function number.hasbit(x, p) -- typical call: if hasbit(x, bit(3)) then ... - return x % (p + p) >= p -end - -function number.setbit(x, p) - return (x % (p + p) >= p) and x or x + p -end - -function number.clearbit(x, p) - return (x % (p + p) >= p) and x - p or x -end - ---~ function number.tobitstring(n) ---~ if n == 0 then ---~ return "0" ---~ else ---~ local t = { } ---~ while n > 0 do ---~ insert(t,1,n % 2 > 0 and 1 or 0) ---~ n = floor(n/2) ---~ end ---~ return concat(t) ---~ end ---~ end - -function number.tobitstring(n,m) - if n == 0 then - if m then - rep("00000000",m) + return bits(n, i+1, i, ...) else - return "00000000" + return bits(n, i+1, ...) end else - local t = { } - while n > 0 do - insert(t,1,n % 2 > 0 and 1 or 0) - n = floor(n/2) - end - local nn = 8 - #t % 8 - if nn > 0 and nn < 8 then - for i=1,nn do - insert(t,1,0) - end - end - if m then - m = m * 8 - #t - if m > 0 then - insert(t,1,rep("0",m)) - end - end - return concat(t) + return ... end end ---~ print(number.tobitstring(8)) ---~ print(number.tobitstring(14)) ---~ print(number.tobitstring(66)) ---~ print(number.tobitstring(0x00)) ---~ print(number.tobitstring(0xFF)) ---~ print(number.tobitstring(46260767936,8)) ---~ print(#number.tobitstring(46260767936,6)) - -function number.valid(str,default) - return tonumber(str) or default or nil +function number.bits(n) + return { bits(n,1) } end |