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Diffstat (limited to 'tex/context/base/mkiv/l-number.lua')
| -rw-r--r-- | tex/context/base/mkiv/l-number.lua | 207 |
1 files changed, 207 insertions, 0 deletions
diff --git a/tex/context/base/mkiv/l-number.lua b/tex/context/base/mkiv/l-number.lua new file mode 100644 index 000000000..001ca31f7 --- /dev/null +++ b/tex/context/base/mkiv/l-number.lua @@ -0,0 +1,207 @@ +if not modules then modules = { } end modules ['l-number'] = { + version = 1.001, + comment = "companion to luat-lib.mkiv", + author = "Hans Hagen, PRAGMA-ADE, Hasselt NL", + copyright = "PRAGMA ADE / ConTeXt Development Team", + license = "see context related readme files" +} + +-- 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 +local concat, insert = table.concat, table.insert +local lpegmatch = lpeg.match + +number = number or { } +local number = number + +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 + +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) + local s = format("%X",n) + if #s % 2 == 0 then + return s + else + return "0" .. s + end +end + +-- 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 + +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 +-- 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 + return bits(n, i+1, i, ...) + else + return bits(n, i+1, ...) + end + else + return ... + end +end + +function number.bits(n) + return { bits(n,1) } +end |