Given an instance myqobject of this class, a Lua program can emit signal mysignal as follows 3 I want to output wikitext like this: I have previously done that and it worked well, but when the text between the tags is more varied, something breaks. If you only want to call some C/C++ functions from Lua (or some small Lua functions from C/C++) - use Lua C API. Its easy to integrate Lua scripts into C/C++ projects. The #invoke speed in March 2013 has been about 180/second, compared to short templates running 350-600 per second, or parser functions >750/second, or character-insertion templates running 2,400/second. ", [ [\w+\. --Iantresman (talk) 11:31, 9 December 2013 (UTC), Can modules "call" other modules? Wnt (talk) 15:52, 22 January 2014 (UTC), Wikipedia:Lua/To do, a page you substantially contributed to, has been nominated for deletion. 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++. I didn't use Special:ExpandTemplates, though - I really did just forget my curly braces. Toohool (talk) 17:18, 27 March 2013 (UTC), I have another related question. is there a better way to do this? The returned integer defines how many return values has been pushed to the Lua stack. with nil arguments removed. 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. Work fast with our official CLI. I think that this is less effective than it could be, however. Most of the time, you only need one Lua state (lua_State in Lua C API and sol::state in sol2) for everything. Currently it is misleading advising to check for double redirects. 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. . Yes, you can replace built-in functions because they are simply functions accessed from global variables. It would be a bit odd. At Module:DisplayLuaTableContents I see numerous loops as, , but I learned that strings are immutable and hence this assignment is rather costly. You can call it with LuaJITs FFI, see the tutorial here. A cross between resources, documentation, and useful links. : Overusing them makes code harder to understand because now you need to make sure that the object youre are pointing to doesnt change unexpectedly. The value of any of these keys will never be. There is still lots of work to do of course, But it's a start TheDJ (talk contribs) 22:18, 18 March 2013 (UTC). 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. Preceding unsigned comment added by Ryn78 (talk contribs) 03:27, 13 October 2013 (UTC), Is it possible for a module to invoke another module? This is not a tutorial or step-by-step guide. Johnuniq (talk) 09:37, 7 October 2013 (UTC). Lua adjusts the number of arguments to the number of parameters, lua.LVAsBool(v LValue) - Convert to bool, nil and false becomes false. Providing global relocations solutions, storage and warehousing platforms and destruction plans. Its much easier to test if something is non-nil or has a specific type/fields in Lua than in C++. Just some of our awesome clients tat we had pleasure to work with. Many 3rd party Lua libraries usually work with Lua 5.2/5.3/5.4. After the function call, Have there been any major incidents yet? For example, Module:Navbar contains the code: In what case would frame not be equal to mw.getCurrentFrame()? I would welcome comments, and if people think the scheme is OK, please consider rating your modules Wnt (talk) 23:31, 16 April 2013 (UTC), I have opened a discussion here: en:Module_talk:String#Replication on other wikis. 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}}. n --Jarekt (talk) 16:24, 14 March 2013 (UTC), Are module authors permitted to use other licenses (presumably in addition to the CC-BY-SA license) for modules they develop? Lori Baker - via Google. If you notice that your C++ function has a huge overhead because of Lua calls, consider using this pattern: // in C++ sol::table t = lua.create_table (); for (int i = 0; i < 1000; i++) { // do stuff in C++, push data to Lua table occasionally } luaFunc (t); -- in Lua function someFunc (t) for k,v in pairs (t) do -- do stuff end end 5. You choose what Lua code can and cant do. 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! Integrating it with CMake is somewhat trickier. I don't think it was really a active decision. or subroutine in other languages) Dont forget that you can do this: Now, when you load/execute this script, you will only get one function as the result: All the internal script state will be hidden and non-modifable and wont overwrite any global state in your current Lua state, which is great. If an argument to a function can be of more then one type the L.CheckTypes(n int, types LValueType) function can be used to check and yield an error to the user. Lua is written in ANSI C, so it can compile almost everywhere. What should I do to return a large text built from numerous smaller elements? --Rotpunkt (talk) 12:35, 1 May 2013 (UTC), Hello, I'm wondering if there is currently a module that counts elements on a page. 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? Also, your feedback here about the best way to organize the data is also welcome. The price they quote you is guaranteed and if your load comes in on the scales below the pounds they quote you they will refund you the difference you paid. extra parameters get nil. OUR MISSION. lua.LVAsString(v LValue) - Converts LString and LNumber to string. I just quickly sorted out the present Lua modules to Wikipedia:Lua/Modules/Overview. Please take a look, critique it, test it, and let me know if there is anything that should change before I look at deploying it to some of the maintenance templates. 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 In brief, the categories I set up were pre-alpha, alpha, beta, release, and protected. That's a bit of boilerplate code that I've been using in all the modules I write. a function definition has a conventional syntax; 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. New versions come out once in a while, but you can comfortably stay on Lua 5.2 not loose much. Cya. Of course, you can check for this files existence and handle errors appropriately (e.g. If you're a Lua developer, please watchlist it. Given that each {{#ifexist:}} is an expensive parser function (EPF), these templates can consume an excessive number of EPFs. 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. In the first case, we use a function call as a statement; You signed in with another tab or window. Isnt it great? Also explains why the uselang=qqq hack doesn't work to show the scribunto messages. Immediately afterward it gives you another line of codes which I have absolutely no idea where to insert it to make it functional at all. 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"? I would use them again if needed. Often the linked module contains bells and whistles that aren't really necessary; why not bring it into the module and slim it down? The approach of Module:Sandbox - having every user put scripts into a common receptacle - seems unworkable. 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"). There are some practical functions to convert and check lua.LValue objects. Hex (? for example, make this work without copying the args to a new table? I am trying to implement {{Horizontal timeline}} as a module. If needed, custom metadata can safely be written to the metadata table; it is unique for each key and will persist for the duration of the load() call. The documentation toolbox does not yet know about Module testcases (though the editnotice 'sort of' does). Does mw.ustring.byteoffset work correctly with negative offsets? d Perhaps li in a list or tr in a table? WebIt's more terse, though at the expense of the function call overhead. I can acquire arguments using the frame.args object passed to a script using an iterator function: But this does not seem to work for a library such as mw.site. What do people think? 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. Please don't take those *personal* suggestions as a criticism to Wikipedia:Lua. Use Git or checkout with SVN using the web URL. 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. :P Anyway, I have taken that idea and added some parameter checking and some documentation, and called it Module:User:Mr. Stradivarius/PrefixIndex. 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. 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. Anyone interested in testing templates may want to try Module:Convert/tester which allows hundreds of tests to be easily defined. Are you sure you want to create this branch? WebWe can disable all the type checking by switching a single variable, and no added overhead would remain when the functions are executed (though there is some slight added overhead when the functions are built). In the example bellow sayHello function is first defined, and then called in the second call to DoString. L.DoString runs the Lua code in the VM. Where I see this is commonly done is in the templates which return links to the archives of talk pages. On each conflict, this function will be passed the conflicted key, the current value that load() is attempting to save, the value that is currently stored in the conflicted key, and a table of metadata consisting of the following: Please note that these keys are created and updated automatically by load() and should not be altered manually. Servicing Northern California For Over 25 Years, Select The Service Your Interested InDocument ShreddingRecords ManagementPortable StorageMoving ServicesSelf StorageOffice MovingMoving Supplies. Keep your global state to a minimum and variable scope as small as possible. Mr. Stradivarius talk 12:54, 10 July 2013 (UTC), We have {{WikiProject Lua/header}} that does the header tabs (I started). This can result in slow compilation times, unreadable error messages and some interfaces are not that friendly (e.g. Casey Moving Systems is family owned and has been servicing Northern California for over 25 years. Check out this engine for making Zelda-likes for inspiration of how to write game code in Lua. Writing code like this will become better with new #embed directive in future C/C++ versions, e.g. My own modules populate only the pre-alpha and alpha categories, but there are some here which I know have reached the other levels. Text formatting (bold, italics) breaks when the ''/''' tags are not closed for each argument. Can they be rewritten in Lua, perhaps? --Vriullop (talk) 11:07, 22 March 2013 (UTC). to use Codespaces. Then, see if you really need to move this code (or parts of it) to C++. Ultimately MediaWiki should issue another tutorial for Wikipedians (without prior knowledge of C and Lua) due to the differences from standard Lua. but this fact has no relevance to Lua programmers. There are still a few things I'm not sure about, though. With your own bindings, you can control what version you use and how the exposed API looks in Lua. Best Mr. Stradivarius talk 10:42, 27 March 2013 (UTC), You've got it pretty much right. I've taken some steps to bring it partially in line with our Template documentation system. If anyone could help me to work this out I'd be very grateful. This code is OK (calling C++ from Lua is cheap): This code is not that good (calling Lua from C++ is slow): Profile first. --Iantresman (talk) 14:50, 8 December 2013 (UTC). mw.site.currentVersion, mw.site.scriptPath, etc etc. For instance, consider the following function, to increment a global counter. This function has 1 as its default argument; that is, the call incCount (), without arguments, increments count by one. When you call incCount () , Lua first initializes n with nil ; the or results in its second operand; and as a result Lua assigns a default 1 to n . I bypassed the most serious problem, but for some reason the method is generating incoming links to nonexisting articles. If you're unaware, {{unsubst}} (along with a few other templates) is used to make it so that entering {{subst:citation needed}} in an article results in {{Citation needed| date=November 2013}} rather than dumping all the template code into the article. Throughout the post L will denote a pointer to lua.LState. It's just that a central repository would be so beneficial for everybody (en.wiki devs/editors included) and en.wiki can't really be (in my honest and personal opinion) that place. 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 Page content can be retrieved with the getContent () method of the title object. Can Lua scripts access the username of the logged in user? An auto sizing callstack will allocate and release callstack pages on demand which will ensure the minimum amount of memory is in use at any time. I ran some local tests and it seems pretty easy to crash it, but then again I'm running it in an unstable environment anyway so it may not reflect how things work here on Wikipedia. thank you. Does this apply if you are accessing the module from another Lua module, and not directly from a wiki page? For instance, all library functions are written in C; 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. You can download the latest release manually and include it in your project, or you can install it in your project directory through Luvit's package manager Lit, using the install command. Makyen (talk) 05:58, 1 January 2014 (UTC), That makes sense. They are iteration functions, so they add the overhead of a function call to each loop iteration. -- Gets numbers for row1, row2, etc. It is superfluous if you only call the function once within the scope of the local variable, but that is pretty rare. Mr. Stradivarius talk 23:06, 1 January 2014 (UTC); Page moved without redirect. 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. What to write in Lua: gameplay logic, FSMs, cutscenes, etc. string.format('%f %f %f', 0.00001, 1.2, 3) => 0.000010 1.200000 3.000000, string.format('%g %g %g', 0.00001, 1.2, 3) => 1e-05 1.2 3, This page was last edited on 4 February 2023, at 15:13. Functions are the main mechanism for abstraction of statements WebLua programs can emit signals using the function call syntax. Because it makes it much easier to track dependencies between various script files and makes them load each other when theyre needed. Iterative multi-file loader, used to load all Lua modules in a directory and return them as one table. the results which can be obtained by a user with the Special:PrefixIndex page)? Now you dont need to ship this init.lua with your binary and life becomes easier. *, I'd like to find out which mw.site library options are available, and print their value, without having to specify each one individually, ie. -- Gets args.rowtype1, args.rowtype2, etc. WebBut when you create thou sands of small tables, the combined overhead can be signic ant. 2015 Nils Lagerkvist. 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). Writing the code in it feels like writing pseudocode/prototyping. Our areas of expertise include Commercial Moving Services, Warehousing, Document Shredding and Storage Solutions. now i wanted to translate Category:Pages with script errors in bn language. 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. Fantastic help. lua.CanConvToString(v LValue) - True if LString or LNumber. !) 16:39, 24 February 2013 (UTC), the following code is arguably better than the current one;-) [Note: It also highlights more Lua features - assertion, type checking, local scoping, tail call recursion etc. A language variable can contain values of any type. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. For example, return {84 = 132}, or return {'84' = 132}, or return {0 = 00}, give errors demanding a } near the =. Is it a good idea to deviate from the template standard of calling pages with testcases, tests for the module namespace? That is partly about performance but mostly about engine architecture. To maintain similarity with other sandbox pages (in template space and user space), I propose: If we agree on this, we can encourage/discourage patterns. 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'});. That is partly about performance but mostly about engine architecture. Johnuniq (talk) 02:22, 25 June 2013 (UTC). Then we call the function with lua_call (). Thank you. What to write in C++: collision detection, path finding, physics, renderer and other things that are performance critical. Much better! With those it's not entirely clear if they are meant to go together or not. For instance, all library functions are written in C; by displaying a message box/writing to a log), but if your init.lua is not meant to be modified externally, maybe you can do it like this? --HectorMoffet (talk) 11:05, 29 December 2013 (UTC). ), The disadvantage of course is that bugfixes in modules like Redirect don't get passed on. -- Sameboat - (talk) 04:26, 19 March 2013 (UTC). E.g. there is no difference between functions defined For example (C++ functions have cpp postfix): Ask yourself: do all these functions need to be in C++? Dealing with C++ objects in Lua is much harder than dealing with native types. The messages for /doc inclusion are currently added as contentlanguage, where really only their parameter should be included as such. If that is not possible: Please suggest an alternative method to implement it. To get automatic errors the L.Check(n int) family of functions can be used; They throw a Lua error if the type check fails. --SocietyBox (talk) 02:26, 20 January 2014 (UTC). In Lua, all arrays are 1-indexed, however t[0] is still valid but that would result in the lenght of the array to be off-by-one. Servicing Stanislaus, San Joaquin and Merced Counties, 2209 Fairview Drive Suite A Ceres, CA 95307. Then, executing script.lua would resullt in an error: SomeClass is nil. how can i do this (on which module, i find this Category for translation). Note: Lua isnt zero-indexed, so the first function argument is fetched with L.ToInt(1), second argument with L.ToInt(2). FT2(Talk|email) 02:07, 20 March 2013 (UTC), I found this guide for learning how to code Lua, may be of help or use www.lua.org/pil/contents.html#P1, I feel like I must have reinvented the wheel here, but I copied Template:Tlx to Template:Mlx with minor modifications, so we can type, and get {{#invoke:ConvertNumeric|decToHex|99 33}}, It would be good if someone could look this over for any flaws before it gets cascade-protected by something. Needs study to guarantee correctness! Can one call lua function that returns sevaral strings and pass them to a template? In short, if your coroutine gets GCed and you hold the reference to this local variable as a sol::object on the C++ side, it wont prevent the variable from getting GCed by Lua and your program crashing because of that. See a simple example of how to build Lua with CMake and use it with sol2 here. This bytecode is converted into LLVM IR and then fed into Deegen, which can transform the functions to do tail calls correctly, use the GHC calling conventions, and a / I am a repeat customer and have had two good experiences with them. --Iantresman (talk) 13:14, 8 December 2013 (UTC). Sandboxing is easy. 1 time resty -e 'ngx.re.find ("hello, world. ], So templates can call Lua modules, parser functions and pages in MediaWiki namespace. I know we are quite far into WP:DEW territory here, but I'd appreciate it if people could comment at the discussion over at Template talk:Lua#Style. This is typically done with a copyright template placed on your user page though you might want to modify one of them to specify that it only applies to Lua modules. WebWhen iterating a table, the function overhead from ipairs does not justify it's use. Thanks. The simplest language I know. During operation, in the event that any functions share the same name, a table will be created with that name and the conflicting functions will be stored there using the name of the script they came from, such that with two scripts foo and bar, both containing the function foo, you would end up with the functions foo.foo and foo.bar. See the demos and more details at WikiProject Flag Template. The system compares actual template output with fixed text, and is only suitable for templates and results that are reasonably short because each template and its expected result have to be in one line. For example: Instead I need to output: "0.00001 1.2 3". 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. Hi, is there a way to instruct string.format to not produce trailing zeros with decimal notation? in the second case, we use it as an expression: Lua also offers a special syntax for object-oriented calls, after imported i find error in article with this Category:Pages with script errors. Youre unlikely to run into performance issues, unless youre making a AA/AAA game or a complex simulation program. For example, it is not printing the string "mw.site.currentVersion", and only two "mw.site.stats" table rows, which might suggest it is not recursing properly, or perhaps something else. Please 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. Older versions of Lua created empty tables with some pre-all ocated slots (four, if I ( Instead of requiring Module:Redirect from a protected module (or in this case a template, Template:Submit an edit request, which serves MediaWiki:Protectedpagetext), you would simply require or link to a copy (Module:Submit an edit request/Redirect). 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. in Lua and functions defined in C. As we have seen in other examples, I've been trying to get to grips with the concept of frames, and I think I'm almost there. There is no reason to do it for functions which are already Is there a way to obtain a list (array) of all pages with a prefix (e.g. Automatic transclusion of protection templates was added. I've created a new request page for Lua scripts at Wikipedia:Lua requests. in C (or in any other language used by the host application). itch.io was written with it and it compiles to vanilla Lua. 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. 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. Will your logo be here as well?. And be especially careful when using coroutines. The function is followed by the arguments, in order. However, the basic API is quite simple, and the advanced features deserves its own post. Does someone have an idea how to code this feature? It uses heavy meta-programming to get things done. Similar to avoiding use of prior utility templates, when writing other utility templates, I would recommend to use the direct #invoke to access Lua functions from a utility template. 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. Anomie 03:36, 1 November 2013 (UTC), User:Wnt and I have had a little disagreement over the type parameter of the {{lua}} template. 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. Wnt (talk) 15:56, 6 January 2014 (UTC). The functions in question had a single parame How you divide up your code among different Updated link. (what is sometimes called procedure 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). Or is it something else? The process was smooth and easy. First lets set up the environment and test that it works, start by install gopher-lua: Secondly lets create a minimal implementation: lua.NewState() creates our Lua VM, and it is though L (*lua.LState) we will interact with Lua in the future. These snippets of Python and Lua are roughly equivalent. I was just trying to return those hex tables via loadData and seem to have run into a nasty surprise. Johnuniq (talk) 22:58, 10 January 2014 (UTC). Basically, you need to tell Lua explicitly that something youve created in the coroutine needs to outlive this coroutine (and this is done with lua_xmove). 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.