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144 lines
4.3 KiB
Plaintext
144 lines
4.3 KiB
Plaintext
LuaBit
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------
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LuaBit is a bitwise operation lib completely written in Lua. It's
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written in the belief that Lua is self-contained.
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The supported operations are: not, and, or, xor, right shift, logic
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right shift and left shift.
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Several utilities are designed to leverage the power of bit operation:
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1. hex: a dec <-> hex number converter
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2. utf8: convert utf8 string to ucs2
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3. noki: convert nokia pc suite backuped SMS file to .txt
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Under the MIT license.
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Visit http://luaforge.net/projects/bit/ to get latest version.
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Status
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------
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Now LuaBit is in v0.4.
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Release date: Mar 18, 2007
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Content
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-------
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3 files are there for LuaBit:
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1) bit.lua
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is the bitwise operation lib, all operations are implemented here.
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2) hex.lua
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is a helper lib for ease of using hex numbers with bitwise
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operation.
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3) noki.lua
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a utility(based on bit and hex) to convert Nokia PC Suite backuped
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SMS to a unicode .txt file, which is more accessible than the
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original .nfb or .nfc file.
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4) utf8.lua
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convert utf8 string to ucs2 string
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How to use
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----------
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Bit
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---
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Just require 'bit' in your project and the bit lib will be
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available:
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bit.bnot(n) -- bitwise not (~n)
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bit.band(m, n) -- bitwise and (m & n)
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bit.bor(m, n) -- bitwise or (m | n)
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bit.bxor(m, n) -- bitwise xor (m ^ n)
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bit.brshift(n, bits) -- right shift (n >> bits)
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bit.blshift(n, bits) -- left shift (n << bits)
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bit.blogic_rshift(n, bits) -- logic right shift(zero fill >>>)
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Please note that bit.brshift and bit.blshift only support number within
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32 bits.
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2 utility functions are provided too:
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bit.tobits(n) -- convert n into a bit table(which is a 1/0 sequence)
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-- high bits first
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bit.tonumb(bit_tbl) -- convert a bit table into a number
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Hex
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---
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For ease of using hex numbers, a utility hex lib is also included in
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LuaBit. You can require 'hex' to use them:
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hex.to_hex(n) -- convert a number to a hex string
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hex.to_dec(hex) -- convert a hex string(prefix with '0x' or '0X') to number
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With hex, you can write code like:
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bit.band(258, hex.to_dec('0xFF'))
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to get the lower 8 bits of 258, that's 2.
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Noki
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----
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require 'noki', to save your sms to .txt file:
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noki.save_sms('nokia.nfb', 'sms.txt')
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and you can view the output sms.txt in notepad or other editor which
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support unicode.
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Utf8
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----
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require 'utf8', to convert a utf8 string:
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ucs2_string = utf8.utf_to_uni(utf8_string)
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History
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-------
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v0.4
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* utf8 to ucs2 converter(utf8.lua).
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* clean up for compatible with Lua5.1 and 5.0.
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* add 'How to use' section for bit.lua and hex.lua.
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v0.3
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* noki added as an application of bit.
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* typo correction.
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v0.2
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* add logic right shift(>>>) support: bit.blogic_rshift.
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* add 2 utility functions: bit.tobits and bit.tonumb.
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* update hex.to_hex(in hex.lua) to support negative number.
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v0.1
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LuaBit is written when I do my own game project(Fio at http://fio.edithis.info).
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When loading resources, I have to do some bit operation. And I do not
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like the embedded way of bit operation. So I decide to implement those
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ops in lua. And that's LuaBit. It's not as fast as the embedded one, but
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it works. And Lua is self-contained :-)
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To-Do List
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---------
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v0.1
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It'll be useful if LuaBit support those bitwise op like:
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bit.band(258, '0xFF')
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ease to type and use. This will be supported in next release.
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v0.2
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I decide to delay this feature to later version for it'll mess up the
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interface of LuaBit.
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v0.3
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May more utility functions add to Noki - phonebook might be a nice candidate.
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v0.4
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There's no UCS2 -> UTF8 convertion now, this feature may add in next release
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or when the project need.
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Noki'll be be exluded from LuaBit in next release; I decide to let Noki grow
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into a powerful tool to support more Nokia PC Suite backup format(.nfb,
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.nfc and .nbu).
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Trial Noki demo at http://nokisms.googlepages.com/(in Chinese)
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Known issues
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------------
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LuaBit doesn't play very well with negative number. The return value of the
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bitwise operations might change to positive when applied on negative numbers
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though the bit sequence is correct. So if you want do some arithmetic with
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the result of bit operation, be careful.
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Feedback
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--------
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Please send your comments, bugs, patches or change request to
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hanzhao(abrash_han@hotmail.com).
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