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Thanks. So many options, so little time. Al > Date: Thu, 31 Jan 2008 15:17:23 -0500 > From: doug.currie@gmail.com > To: lua@bazar2.conectiva.com.br > Subject: Re: Larger data types... > > On Thursday, January 31, 2008 Al Pfalzgraf wrote: > > > I am applying Lua to a DeviceNet protocol project. DeviceNet has a > > very large set of data types including some 64 bit types. Within C > > code they can be declared using __int64 or unsigned __int64. > > > > lua_pushnumber results in warnings or errors with these. > > warning C4244: 'function' :conversion from '__int64 ' to 'double ', possible loss of data > > warning C4244: 'function' : conversion from 'unsigned __int64 ' to 'double ', possible loss of data > > error C2520: conversion from unsigned __int64 to double not implemented, use signed __int64 > > > > Is there an extension library that addresses this, or am I about to create one? > > You can do it without an extension by abusing the string type: since > strings are really just blobs of bits, you can make 8 byte binary > strings for your large numbers, e.g., with lua_pushlstring(), and get > them back with lua_tolstring(). > > If you find this distasteful :-) ... you can still get by without an > extension by storing the large numbers as a table or tuple (search > http://lua-users.org/wiki/FindPage for "tuple"). > > A pure Lua approach using tables: > http://oss.digirati.com.br/luabignum/index.htm > > There are other add-on approaches... > > Lnum, http://luaforge.net/projects/lnum/ modifies the Lua core to have > large numbers. > > And libraries... > > Bignum, http://luaforge.net/projects/bignum/ adds support for "big > integers based in the BIGNUM of the OpenSSL C package." > > LGMP, http://members.chello.nl/~w.couwenberg/lgmp.htm is a available. > > There is also a Lua binding for MAPM > http://www.tecgraf.puc-rio.br/~lhf/ftp/lua/lmapm.tar.gz > > e > > -- > Doug Currie > Londonderry, NH, USA > Need to know the score, the latest news, or you need your Hotmail®-get your "fix". Check it out. |