The approach of Module:Sandbox - having every user put scripts into a common receptacle - seems unworkable. WebDue to the short-circuiting behavior of or, it will generally impose little additional overhead at call-time: local soundit; do local sounds; function soundit (x) sounds = sounds or { a = "ay" , b = "bee" , c = "see" , . } assert ( type (x) == "string" ) return sounds [x] end end If a conflict can not be resolved in a satisfactory manner, the function should throw an error to signify this; returning false or nil will result in that value being written to the key. lua Currently, there are a reasonable number of templates that try to determine if any of a set of pages exist in order to provide links to those pages. Any suggestion on how to receive this parameter template as a table rather than a substituted string? The reference manual for Lua 5.4s C API is here: https://www.lua.org/manual/5.4/manual.html#4, Github repo: https://github.com/ThePhD/sol2. All rights reserved. Similarly to the previous advice, when defining classes (e.g. What can I do to increase the performance of a Lua If you only want to call some C/C++ functions from Lua (or some small Lua functions from C/C++) - use Lua C API. I wonder if there's any actually helpful tutorial for those already familiar with Wikisyntax but without other computer language experience like Lua or C. The tutorials I found usually begin with a simple code to tell you to copy-and-paste (hello, world) then look at the outcome. To iterate a table, instead use for k=1, #tbl do local v = tbl [k]; It does exactly the same without the function call overhead (pairs actually returns another function which is then called for Hopefully this will be semi-useful again. Because the property from Wikidata is not updated by mw.message, I decided to try it on one of those pesky Special: pages that abolish caching. also, if someone already wrote a module that does the same thing, let me know and I will have this one deleted. This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository. The easy part is 'getting rid of the function name': assuming p is the variable in the last line of the program, just say, However, I see no way to get rid of the pipe - it. Exposing Go functions to Lua is essential to create custom a custom API. the results which can be obtained by a user with the Special:PrefixIndex page)? I've been trying to get to grips with the concept of frames, and I think I'm almost there. itch.io was written with it and it compiles to vanilla Lua. I was going to deploy it on Template:Year in other calendars/testcases, but in my preview it runs out of time by the time it gets to the last test. Makyen(talk) 04:02, 8 May 2014 (UTC), I've heard for quite a while that the Lua scripts only run when the page is parsed, which rules out many interactive features but is efficient. 2000 powered by Hugo Its neat. How to implement action sequences and cutscenes in Lua, Making and storing references to game objects (entities) in C++ and Lua, https://www.lua.org/manual/5.4/manual.html#4. Wnt (talk) 23:14, 21 March 2013 (UTC), I have run many timing tests, to compare using shell templates which contain #invoke versus direct use of {#invoke:}, and for tiny templates, such as string-handling functions, the template versions often ran upto 50% slower than direct #invoke of each tiny Lua function. Is this a problem in my module or in Scribunto? Johnuniq (talk) 09:37, 7 October 2013 (UTC). I also worked on a fork of LuaJIT professionally and described my experiences here - this experience made me learn a lot about LuaJIT and how vanilla Lua works (and how it can be used in production for servers with a very high QPS). I am trying to create a weblink by concatenating 2 strings and by avoiding the display of the full link in an infobox. Ginsuloft (talk) 13:39, 30 October 2013 (UTC), currently, in Module:Historical populations, I am using a somewhat convoluted method to access 'formatnum' which involves passing 'frame' and using 'callParserFunction'. However, the basic API is quite simple, and the advanced features deserves its own post. Makyen (talk) 05:58, 1 January 2014 (UTC), That makes sense. This will make your life easier, because you would be able to write less binding code and be able to stay inside Lua code as much as possible. You can call a function with a number of arguments different from Dcoetzee 23:09, 23 February 2013 (UTC), There's a discussion at the technical pump currently about where to put code that you're experimenting with; as a result Module:Sandbox has been created. ), You dont need a specialized IDE or tools to write Lua comfortably. It stays global and doesnt get collected by a GC until it has been set to nil. :P Anyway, I have taken that idea and added some parameter checking and some documentation, and called it Module:User:Mr. Stradivarius/PrefixIndex. This first edition was written for Lua 5.0. And finally, see what LVE and PICO-8 do. Please don't take those *personal* suggestions as a criticism to Wikipedia:Lua. Needs study to guarantee correctness! While still largely relevant for later versions, there are some differences.The fourth edition targets Lua 5.3 and is available at Amazon and other bookstores.By buying the book, you also help to support the Lua project. The sandbox Wiki code {{Special:AllPages|namespace=666}} {{CURRENTTIMESTAMP}} returns a timestamp that changes each time the page is reloaded, because caching is disabled. There are some practical functions to convert and check lua.LValue objects. If that is not possible: Please suggest an alternative method to implement it. There are still a few things I'm not sure about, though. {\displaystyle d=3^{(n/2000)}.} Long story short, the overhead of a direct (non-virtual) function call was approximately 5.5 nanoseconds, or 18 clock cycles, compared to an inline function call. The overhead of a virtual function call was 13.2 nanoseconds, or 42 clock cycles, compared to inline. These timings are likely different on different processor families. -- Gets numbers for row1, row2, etc. Gut feeling is usually wrong. Perhaps li in a list or tr in a table? In Module:Sidebar, I extended the boilerplate further to allow a third way, invoking the module from a template and passing args in explicitly (instead of using whatever args were passed to the template), like {{#invoke: Navbar | arg1 = foo | arg2 = bar}}. --HectorMoffet (talk) 11:05, 29 December 2013 (UTC). Relevant to Lua, userscripts, and user scripting generally. You dont need to compile Lua code, which means that you can change parts of your program/game logic without recompiling and even without reloading your program. Can templates, MediaWiki pages or parser functions be called from Lua? The typecheck function could also store away the type info for later introspection. They are iteration functions, so they add the overhead of a function call to each loop iteration. See the explanation on how to do concurrency in Lua in sol2 here (especially about lua_xmove and sol::main_object). via middleclass library), dont do it like this: and then, when you want to create an instance of this class, you do this: Why do it like this? I was wondering if there is a way to improve the performance. Putting the following into the debug window gives the values shown: I don't need the functionI'm just asking if it has a bug. You might also find Moonscript interesting. --Iantresman (talk) 13:14, 8 December 2013 (UTC). The NewPP parser hits the huge delays when passing 6,000 parameters whether to Lua, or to a template, or to a #switch parser function of 6,000 "|x=" branches. For example like: frame.args.row1. WebFunctions used by a Lua program can be defined both in Lua and in C (or in any other language used by the host application). sol2 is a fantastic library which Ive used for many years. Updated link. While running tests to simulate a large #switch function of 3,000 branches, I repeatedly confirmed how passing thousands of parameters is typically exponentially slower beyond the first 500 parameters. that is, to call o.foo adding o as a first extra argument. is to create and maintain customer confidence with our services and communication. Mr. Stradivarius talk 01:15, 29 October 2013 (UTC), How well does Scribunto defend itself against DoS, or possibly XSS, but especially DoS as we are dealing with a Turing-complete language? functions --Rotpunkt (talk) 12:35, 1 May 2013 (UTC), Hello, I'm wondering if there is currently a module that counts elements on a page. We could also use the template to automatically add Category:Lua-based templates to keep track of converted templates more easily. To get the perf bit Its simple. And to fetch an argument without conversion the L.Get(n int) function can be used. New versions come out once in a while, but you can comfortably stay on Lua 5.2 not loose much. So tonight I put together Module:Unsubst, which can be used to do the same thing without all the limitations of {{unsubst}}. For instance, if we have a function like. I've created a new request page for Lua scripts at Wikipedia:Lua requests. Many 3rd party Lua libraries usually work with Lua 5.2/5.3/5.4. The tutorial I actually want is how a template with parser functions translate into a Lua module with explanation of what syntax equal what variable/function or whatever. for example, make this work without copying the args to a new table? Enrique Garca Cota has a lot of great articles about Lua: http://kiki.to/. Using the L.CheckTypes function equate to checking the type manually and then calling L.TypeError(n int, message string) if there is an error. To do this it calls the Lua bytecode compiler and then it converts the bytecode to C. For each function in the module, the code generator produces an appropriate function header and then it iterates over the functions bytecodes, outputting a block of C code for each instruction. With a clear upsream in a central place like mediawiki.org then en.wiki and other Wikimedia projects could work better on local support and whatever is specific to their communities. Automatic insertion of the green 'chrome' of our template documentation. ?0" here but useful if omit above. The advantages are a) edits to Redirect to add irrelevant features don't lead to massive queue usage, b) Redirect doesn't have to be protected, and c) in case a required module isn't protected, you don't get confused and fool around with a module you think is in limited use only to find out that you've created a huge server load. This doesn't, which I was hoping would be equivalent: And, how do I do the reverse, and convert mw.site.currentVersion to the string "mw.site.currentVersion"? What to write in C++: collision detection, path finding, physics, renderer and other things that are performance critical. Are you sure you want to create this branch? I just quickly sorted out the present Lua modules to Wikipedia:Lua/Modules/Overview. They have a great system for tracking your belongings and a system for checking to make sure you got all of your belongings once you arrive at your destination. The parameters object takes three important parameters: Fn - the lua.LFunction to call Nret - The number of returned values Protect - If protect is true an error is returned, otherwise a panic will occur. Thank you!--QuimGil (talk) 07:52, 21 June 2013 (UTC). A complete example looks like this: The LState defines some convenience functions, in the example above we are using L.ToInt(1) to fetch the first function argument. Your help pointing to ways to improve is welcome. Johnuniq (talk) 06:53, 11 October 2013 (UTC), Doesn't Wikipedia's version of Lua allow the GetURL function (or equivalent)? Please I was just trying to return those hex tables via loadData and seem to have run into a nasty surprise. The related, but separate issue, for speed of #invoke, can quicken every use of Lua, if 1.22wmf1 successfully doubles the speed of each #invoke. To be sure, this is the strip marker for a current time function, but I'm thinking this is either a bug or a feature, and we should figure out which! It would be a bit odd. The general method that has been used is to assume a format for the page archive name and then test for the existence of all such possible pages using {{#ifexist:}}. The same can be said about making your program expandable with plugins. Lori Baker - via Google. Please take a look at Module:RepeatString and Template talk:Repeat and see what you think. Please comment over there if you're interested. I very much regret that. Mr. Stradivarius talk 09:47, 11 November 2013 (UTC), I've updated Wikipedia:Lua/Modules/Overview using a Lua module to generate a table from various simple cut and paste data. Snipre (talk) 07:52, 31 October 2013 (UTC), Is there a LUA method for '#ifexist' that doesn't generate false incoming links? Writing code like this will become better with new #embed directive in future C/C++ versions, e.g. Its a good starting point for making your own CMake build for Lua, though (or if you use older versions of Lua, they work well). Maybe. The compiler might decide "hey, this function is only called a few times, and I'm supposed to optimize for speed, so I'll just inline this f Lua has eight basic types: nil (undefined) boolean (boolean) number (numeric) string (string) If you used classes as globals (which Ive seen in many tutorials and real code), you might have a script like this: Suppose that you didnt execute some_class.lua first (which defines a global SomeClass). :) Wnt (talk) 08:16, 20 November 2013 (UTC), Can Lua take the contents of a Wiki page, and reprocess it? What functions should be called in C++ gameloop from Our areas of expertise include Commercial Moving Services, Warehousing, Document Shredding and Storage Solutions. Automatic transclusion of protection templates was added. Sandboxing is easy. The second clause supports a simple way to invoke the function from another module (such as from Module:Navbox), or from the debug console: Navbar.navbar({arg1 = 'foo', arg2 = 'bar'});. Although Lua can still process the 6,000 parameters, to compare choices, within "0.02" Lua seconds, the load time of the #invoke interface is 27 seconds. Your life will be easier if you have a small C/C++ API. I bypassed the most serious problem, but for some reason the method is generating incoming links to nonexisting articles. The parameters object takes three important parameters: The following code defines a concat function in Lua. You can find Luas reference manual here. Frietjes (talk) 16:17, 30 October 2013 (UTC). Given an instance myqobject of this class, a Lua program can emit signal mysignal as follows To simplify comparisons, when comparing metadata the following can always be assumed to be true: From this data or according to any other criteria, the handler function should resolve the conflict by returning the value that should be written to the conflicted key. This was possible because the wikimarkup language was very intuitive, and easy to understand even for the layman. To get the perf bit out of the way: the bridging code between C++/Lua has overhead compared to just calling Lua from Lua or calling C++ from C++. a function definition has a conventional syntax; However, sometimes that is just not enough and an embedded language can be the solution. Calls the concat function with the arguments Go and Lua and prints the resulting string to stdout. ", [ [\w+\. In the first case, we use a function call as a statement; Think of Lua scripts as functions - you can call them with require or do_file and they can return variables. Currently it is misleading advising to check for double redirects. Its easy to integrate Lua scripts into C/C++ projects. What am I doing wrong? = Thanks! All values in Lua can be stored in variables, used as arguments when calling functions, and returned as the result of their execution. Preceding unsigned comment added by Ryn78 (talk contribs) 03:27, 13 October 2013 (UTC), Is it possible for a module to invoke another module? Its much easier to test if something is non-nil or has a specific type/fields in Lua than in C++. At Module:DisplayLuaTableContents I see numerous loops as, , but I learned that strings are immutable and hence this assignment is rather costly. Right now I'm putting ratings on the documentation subpages, which I think is what someone suggested before at one point for categories. It is superfluous if you only call the function once within the scope of the local variable, but that is pretty rare. For example: Instead I need to output: "0.00001 1.2 3". My new test module Module:Sandbox/iantresman/sandbox/archive/mw.recursive prints out "frame.args" arguments passed to it, but is not recursively printing "mw.site" library functions/table when accessed from User:Iantresman/sandbox/archive/mw.recursive. --Rotpunkt (talk) 13:50, 9 January 2014 (UTC), mediawikiwiki:Extension talk:Scribunto/Lua reference manual #Example for string.format? In Chapter 16 we will discuss such calls And be especially careful when using coroutines. !) 16:49, 3 April 2013 (UTC), I've created five categories for different levels of Lua module progress: since each explains the others, Category:Modules in alpha should be sufficient. Normally this wouldn't be an issue, except I was wondering if you write a Lua module that requires another Lua module or mw.title.new()s a data file, is the target module or file protected when the main module is cascade-protected? How much do function calls impact performance? Of course, you can check for this files existence and handle errors appropriately (e.g. However, after writing up Module:Hex, which hex dumps the contents of strings, I was looking at the talk page when I noticed that the hex-dump of the contents of a strip marker (the example with UNIQ QINU) are changing every single time I hit the Talk tab or browser reload button to reload the page, even when I'm completely logged out with scripts disabled! Caution is desirable because it is very confusing for anyone reading the code later if tostring() does not do what it normally does, however the following is the idea. Mr. Stradivarius talk 16:45, 29 March 2013 (UTC), I decided to implement a Lua replacement for the innards of {{Repeat}} as a learning project for my first Lua module. You're looking for performance in the wrong place. The problem with function calls is not that they cost much. There is another problem. Function c I've been trying to use some of the other frame functions, and I can get them working via #invoke, but not through the debug console. Anyone interested in testing templates may want to try Module:Convert/tester which allows hundreds of tests to be easily defined. For example, suppose that you have C++ code like this: Your engine will crash on startup if init.lua is not found when your game starts (or contains errors). It relies on Module:Sandbox/QuimGil/Flagicon, which provides the logics, and Module:Sandbox/QuimGil/FlagTranslations, where the flags data is stored. He has also implemented a number of incredible little libraries which Ive used in my projects: Many other great libraries can be found via LuaRocks: https://luarocks.org/. Unfortunately, I have not yet been able to think of a way to mix this logic to get what I want, namely a way to control whether results are updated daily or weekly, etc., because I haven't thought of a way by which the logic of whether time has passed will always be evaluated but the logic of the page content will not be, unless the time has come, at which point the caching should be updated on that page. Johnuniq (talk) 22:58, 10 January 2014 (UTC). is just another way to write o.foo(o, x), The function signature must match what you passed in. http://godoc.org/github.com/yuin/gopher-lua, http://github.com/otm/embedding-lua-in-go, http://godoc.org/github.com/yuin/gopher-lua#LTable. These snippets of Python and Lua are roughly equivalent. Then, see if you really need to move this code (or parts of it) to C++. Does this apply if you are accessing the module from another Lua module, and not directly from a wiki page? in C (or in any other language used by the host application). Each layer of "shell templates" (to #invoke a Lua function) also increases the expansion depth by about +2 levels of the 41-level limit (shows "41/40"). These timings are likely different on different processor Everyone took really good care of our things. I don't know, but with some of these things being transcluded on every page in the wiki, and having elaborate powers to write anything they can slip by the interface, we should be wary of security holes, and the first step is to know quickly and certainly which are a unit, I think. --Aftab1995 (talk) 15:50, 23 May 2013 (UTC), I'm very happy to announce that Template:FlagiconLua has reached feature parity with Template:Flagicon!