I have an nspire calculator and after writing a hash table implementation, found the BASIC environment to be a pretty offensive programming environment. Unfortunately, as far as I'm aware, it's impossible to use Lua to write libraries.
I did see that somewhere in the Lua interface you can detect variable changes so it might be possible within a file to use Lua functions, but I fear it will go out of scope if used externally.
Is there a better way to do this?
It's not impossible to write Lua libraries for a TI-Nspire. You can put the libraries code into a string, store it as a variable in TI-Basic and put the file in the MyLibs folder. Then, when you want to load your library, do loadstring(var.recall("libfilename/programstring"))(). This will load the library's code as a string from that files, compile it (using loadstring), and execute it (practicaly the same as require).
Also, about getting from controlling a Lua script using TI-Basic, depending on what you want to do, you could use math.eval("<some TI-Basic code>"). This will execute the code in TI-Basic, and return the result as a Lua value (or string). This way, you can call a TI-Basic function every once in a while, and act according to its output.
Related
I want to make a small "library" to be used by my future maxima scripts, but I am not quite sure on how to proceed (I use wxMaxima). Maxima's documentation covers the save(), load() and loadFile() functions, yet does not provide examples. Therefore, I am not sure whether I am using the proper/best way or not. My current solution, which is based on this post, stores my library in the *.lisp format.
As a simple example, let's say that my library defines the cosSin(x) function. I open a new session and define this function as
(%i0) cosSin(x) := cos(x) * sin(x);
I then save it to a lisp file located in the /tmp/ directory.
(%i1) save("/tmp/lib.lisp");
I then open a new instance of maxima and load the library
(%i0) loadfile("/tmp/lib.lisp");
The cosSin(x) is now defined and can be called
(%i1) cosSin(%pi/4)
(%o1) 1/2
However, I noticed that a substantial number of the libraries shipped with maxima are of *.mac format: the /usr/share/maxima/5.37.2/share/ directory contains 428 *.mac files and 516 *.lisp files. Is it a better format? How would I generate such files?
More generally, what are the different ways a library can be saved and loaded? What is the recommended approach?
Usually people put the functions they need in a file name something.mac and then load("something.mac"); loads the functions into Maxima.
A file can contain any number of functions. A file can load other files, so if you have somethingA.mac and somethingB.mac, then you can have another file that just says load("somethingA.mac"); load("somethingB.mac");.
One can also create Lisp files and load them too, but it is not required to write functions in Lisp.
Unless you are specifically interested in writing Lisp functions, my advice is to write your functions in the Maxima language and put them in a file, using an ordinary text editor. Also, I recommend that you don't use save to save the functions to a file as Lisp code; just type the functions into a file, as Maxima code, with a plain text editor.
Take a look at the files in share to get a feeling for how other people have gone about it. I am looking right now at share/contrib/ggf.mac and I see it has a lengthy comment header describing its purpose -- such comments are always a good idea.
For principiants, like me,
Menu Edit:configure:Startup commands
Copy all the functions you have verified in the first box (this will write your wxmaxima-init.mac in the location indicated below)
Restart Wxmaxima.
Now you can access the functions whitout any load() command
I am trying to hack a game (not for cheating though) by introducing new built-in methods and functions in order to communicate with the game using sockets. Here is a small "pseudo code" example of what I want to accomplish:
Inside the Lua code I am calling my_hack() and pass the current game state:
GameState = {}
-- Game state object to be passed on
function GameState:new()
-- Data
end
local gameState = GameState:new()
-- Collect game state data and pass it to 'my_hack' ..
my_hack(gameState)
and inside my_hack the object is getting sent away:
int my_hack(lua_State * l)
{
void* gameState= lua_topointer(l, 1);
// Send the game state:
socket->send_data(gameState);
return 0;
}
Now, the big question is how to introduce my_hack() to the game?
I assume, that all built in functions must be kept in some sort of lookup table. Since all Lua code is getting interpreted, functions like import etc. will have to be statically available, right? If that is correct, then it should be "enough" to find out where this code is residing in order to smuggle my code into the game that would allow me to call my_hack() in a Lua script.
There should be two options: The first is that the Lua built is embedded inside the executable and is completely static and the second is that all Lua code gets loaded dynamically from a DLL.
This question goes out to anybody who has a slightest clue about where and how I should keep looking for the built in functions. I've tried a few things with Cheat Engine but I wasn't too successful. I was able to cheat a bit ^^ but that's not what I'm looking out for.
Sorry for not providing a full answer, but if you can provide a custom Lua VM and change the standard libraries, you should be able to to change the luaL_openlibs method in the Lua source to provide a table with my_hack() inside of it.
Since the Lua interpreter is usually statically compiled into the host executable, modifying the interpreter in some way will probably not be possible.
I think your best bet is to find some piece of Lua code which gets called by the host, and from that file use dofile to run your own code.
My main goal is to either make my lua file into executable or make it into a bite code.
preferably both of them.
I am trying srlua,but in readme file it tells me to do:
"For Windows, you need to create srlua.exe and glue.exe first. Then for each
Lua program that you want to turn into a stand-alone program, do
glue srlua.exe prog.lua prog.exe
Of course, you can use any name instead of prog.exe."
and when I am trying to compile it using codebluck to get(srlua.exe),I get this :
and what dose it mean by this?
glue srlua.exe prog.lua prog.exe
where should I type that it.
Thanks in advance.
Type it into your shell. Once you have the binary of srlua, that takes "prog.lua" and glues it to "srlua.exe" making "prog.exe". Of course, you need glue as well. You can get an srlua binary and a glue binary for Lua 5.1 here. http://www.tecgraf.puc-rio.br/~lhf/ftp/lua/#srlua
I read this paragraph from the Delphi Tools Site
Changes since the last SVN update are:
Added support for FreePascal-like compile-time $INCLUDE “macros”:
%FILE% and %LINE% insert the current filename and line number into the source
%FUNCTION% inserts the current function name, or class.method name into the source
%DATE% and %TIME% allow inserting the compile date/time
Is there a way we can define macros in DWScript (other than these functions) just like people define macors in excel (using VBscript) in a simple way, where the name of the script will be the name of the function that will be used later, without adding {$Include XXX} in the executed script?
N.B.: I konw this can be done by managing the written script to be saved in a certain file called functions for ex. then save the added function with its name to be used (Add), then the user will write Add(1,2) to get the result; but my boss at work wants it to be something that looks like vbscript in excel.
I'm not sure to understand the question, so I'll list various answers to various possible interpretations...
If you want to declare functions that are implicitly supported by the scripting engine without having to "{$include}" or "uses" them, you can declare them via a TdwsUnit component, and attach it to the script component. If you don't have the "coExplicitUses" option set, they'll be available automatically, and you get design-time support in the IDE.
If you want to add internal functions (that are always there), use one of the RegisterInternalFunction overloads, you can check any of the "dwsXxxxFunctions.pas" units for examples. That's potentially more efficient, but also more cumbersome.
If you want to pre-process custom source-level macros in the source code (ala C's macros), you can use the filters functionality (check the HTML or JS filters as example of how a filter can be implemented).
If you want to react dynamically to "unknown" names, so you can declare them on the spot or bind them to something dynamically, you can use TdwsLanguageExtension.FindUnknownName, that's how the RTTI environment works f.i. (see TRTTIEnvironment in dwsRTTIConnector).
If you want to parse completely custom areas of code in a completely custom way, you can use language extensions too, override ReadInstr and check how asmLib & the JSLibModule do it to support "asm".
I am using the C Fuzzy API and I want to load function module contained in a file lets say mycalculator.lua. This seem to run fine however when I later try to run another file A.lua that requires 'mycalculator' it does not work unless the mycalculator.lua file is available on the file system to reload. I am trying to just load it into the system and then have it available without having the mycalculator.lua in the file system. It there any way to have lua system keep the definition without loading it again? Basically I convert the mycalculator.lua into a string and then run it. I don't want to put mycalculator.lua file into the file system, I just want to hand it over as a string and then be able to require it in the next string I pass to the stack Thanks
There is a difference between simply executing a Lua script and loading a Lua module. If you wish to load a Lua module, then you must actually load a Lua module exactly as a script would: by calling require.
Since you appear to be new to Lua, I should probably explain this. You've probably seen code like this in Lua scripts:
require 'mycalculator'
That is not some special statement to Lua. That is a function call. It is just some syntactic sugar for:
require('mycalculator')
Functions in Lua can be called with NAME VALUE syntax instead of NAME(...) syntax, but it only allows you to send one parameter. And the parameter must be a literal (or table constructor).
In order to call the Lua require function from C, you must use the Lua stack. You must fetch the function from the global table by using lua_getfield(L, LUA_GLOBALSINDEX, "require"); Then, you push a string onto the stack containing the name of the module to load. Then, you use lua_pcall or whatever Lua function calling function to call it.