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1 | bitlib |
2 | ------ |
3 | |
4 | by Reuben Thomas <rrt@sc3d.org> |
5 | http://luaforge.net/projects/bitlib |
6 | |
7 | |
8 | bitlib is a C library for Lua 5.1 that provides bitwise operations. It |
9 | is copyright Reuben Thomas 2000-2009, and is released under the MIT |
10 | license, like Lua (see http://www.lua.org/copyright.html; it's |
11 | basically the same as the BSD license). There is no warranty. |
12 | |
13 | Please report bugs and make suggestions to the email address above, or |
14 | use the LuaForge trackers. |
15 | |
16 | Thanks to John Passaniti for his bitwise operations library, some of |
17 | whose ideas I used, to Shmuel Zeigerman for the test suite, to |
18 | Thatcher Ulrich for portability fixes, and to Enrico Tassi, John |
19 | Stiles and Eduardo Ochs for bug reports. |
20 | |
21 | |
22 | Installation |
23 | ------------ |
24 | |
25 | As normal: |
26 | |
27 | ./configure && make [&& make check] [&& make install] |
28 | |
29 | If you get warnings about integer constants being too large, don't |
30 | worry. They won't be used. |
31 | |
32 | The following options may be of interest if you have Lua installed on |
33 | non-default paths (as you are likely to on any system supporting more |
34 | than one version of Lua): |
35 | |
36 | --libdir=DIR Install shared library in this directory |
37 | --with-lua-prefix=DIR Lua files are in DIR |
38 | --with-lua-includes=DIR Lua include files are in DIR |
39 | --with-lua-libraries=DIR |
40 | Lua library files are in DIR, or "no" if not used |
41 | --with-lua-suffix=ARG Lua binary and library files are suffixed with ARG |
42 | |
43 | For example, on Debian or Ubuntu: |
44 | |
45 | ./configure --libdir=/usr/local/lib/lua/5.1 --with-lua-includes=/usr/include/lua5.1 --with-lua-suffix=5.1 --with-lua-libraries=no |
46 | |
47 | |
48 | Use |
49 | --- |
50 | |
51 | Make sure the library is installed on your LUA_CPATH, and require it. |
52 | |
53 | The library provides the constant bit.bits that gives the number of |
54 | bits that can be used in bitwise operations, and the following |
55 | functions: |
56 | |
57 | bit.cast(a) cast a to the internally-used integer type |
58 | bit.bnot(a) returns the one's complement of a |
59 | bit.band(w1, ...) returns the bitwise and of the w's |
60 | bit.bor(w1, ...) returns the bitwise or of the w's |
61 | bit.bxor(w1, ...) returns the bitwise exclusive or of the w's |
62 | bit.lshift(a, b) returns a shifted left b places |
63 | bit.rshift(a, b) returns a shifted logically right b places |
64 | bit.arshift(a, b) returns a shifted arithmetically right b places |
65 | |
66 | All function arguments should be integers that fit into the C type |
67 | lua_Integer. |
68 | |
69 | The logical operations start with "b" for "bit" to avoid clashing with |
70 | reserved words; although "xor" isn't a reserved word, it seemed better |
71 | to use "bxor" for consistency. |