From e84a0c500a2104dc82b8278d7778144351aa71b3 Mon Sep 17 00:00:00 2001
From: Philipp Gesang <megas.kapaneus@gmail.com>
Date: Fri, 19 Oct 2012 18:35:14 +0200
Subject: update l-number l-boolean

---
 lualibs-number.lua | 82 ++++++++++++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 79 insertions(+), 3 deletions(-)

(limited to 'lualibs-number.lua')

diff --git a/lualibs-number.lua b/lualibs-number.lua
index a1249f0..a4dbe3b 100644
--- a/lualibs-number.lua
+++ b/lualibs-number.lua
@@ -6,11 +6,15 @@ if not modules then modules = { } end modules ['l-number'] = {
     license   = "see context related readme files"
 }
 
-local tostring = tostring
-local format, floor, insert, match = string.format, math.floor, table.insert, string.match
+-- this module will be replaced when we have the bit library
+
+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 { }
+number       = number or { }
+local number = number
 
 -- a,b,c,d,e,f = number.toset(100101)
 
@@ -56,3 +60,75 @@ function number.bits(n,zero)
     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)
+        else
+            return "00000000"
+        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)
+    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
+end
-- 
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