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1if not modules then modules = { } end modules ['l-number'] = {
2    version   = 1.001,
3    comment   = "companion to luat-lib.mkiv",
4    author    = "Hans Hagen, PRAGMA-ADE, Hasselt NL",
5    copyright = "PRAGMA ADE / ConTeXt Development Team",
6    license   = "see context related readme files"
7}
8
9-- See l-number.lua for the more generic (also 5.2) versions of the
10-- functions below ... that file evolved over time.
11
12local tonumber = tonumber
13local format = string.format
14local concat = table.concat
15local floor = math.floor
16
17number       = number or { }
18local number = number
19
20-- print(number.tobitstring(8))
21-- print(number.tobitstring(14))
22-- print(number.tobitstring(66))
23-- print(number.tobitstring(0x00))
24-- print(number.tobitstring(0xFF))
25-- print(number.tobitstring(46260767936,4))
26
27local t = {
28    "0", "0", "0", "0", "0", "0", "0", "0",
29    "0", "0", "0", "0", "0", "0", "0", "0",
30    "0", "0", "0", "0", "0", "0", "0", "0",
31    "0", "0", "0", "0", "0", "0", "0", "0",
32}
33
34function number.tobitstring(b,m,w)
35    if not w then
36        w = 32
37    end
38    local n = w
39    for i=0,w-1 do
40        local v = (b>>i) & 0x1 -- bextract(b,i)
41        local k = w - i
42        if v == 1 then
43            n = k
44            t[k] = "1"
45        else
46            t[k] = "0"
47        end
48    end
49    if w then
50        return concat(t,"",1,w)
51    elseif m then
52        m = 33 - m * 8
53        if m < 1 then
54            m = 1
55        end
56        return concat(t,"",1,m)
57    elseif n < 8 then
58        return concat(t)
59    elseif n < 16 then
60        return concat(t,"",9)
61    elseif n < 24 then
62        return concat(t,"",17)
63    else
64        return concat(t,"",25)
65    end
66end
67
68function number.valid(str,default)
69    return tonumber(str) or default or nil
70end
71
72function number.toevenhex(n)
73    local s = format("%X",n)
74    if #s % 2 == 0 then
75        return s
76    else
77        return "0" .. s
78    end
79end
80
81function number.bytetodecimal(b)
82    local d = floor(b * 100 / 255 + 0.5)
83    if d > 100 then
84        return 100
85    elseif d < -100 then
86        return -100
87    else
88        return d
89    end
90end
91
92function number.decimaltobyte(d)
93    local b = floor(d * 255 / 100 + 0.5)
94    if b > 255 then
95        return 255
96    elseif b < -255 then
97        return -255
98    else
99        return b
100    end
101end
102
103function number.idiv(i,d)
104    return i // d
105end
106