lua function return multiple values

Why are so many coders still using Vim and Emacs? Convolution Neural Network in torch. I'm not looking to use such behavior, and I realise that you could replicate it by returning a table and unpacking that, I just want to know if it's meant to work (as it's valid Lua syntax) and I can't find a definitive answer on this anywhere. Moonsharp pairs(…) raises exception “bad argument #1 to 'next' (table expected, got string)”, How to use recursive function in Lua to dynamically build a table without overwriting it each call. Returning multiple values from a function - Lua. site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. element of a list of expressions, then no adjustment is made (unless This task is rather difficult, if not impossible at all. rev 2020.11.11.37991, Stack Overflow works best with JavaScript enabled, Where developers & technologists share private knowledge with coworkers, Programming & related technical career opportunities, Recruit tech talent & build your employer brand, Reach developers & technologists worldwide, @towi you have to implement element-wise comparison yourself. Please see the linked article for further explanation. Why is "hand recount" better than "computer rescan"? When a variable amount of results are returned by a function, one can store them all in a table, by executing the function inside it: This way, one can iterate over the results table to see what the function returned. Lua 5.1.3 I havent integrated into. I … Making statements based on opinion; back them up with references or personal experience. end subroutine foo To return multiple values from a function, you can pack the return values as elements of an array or as properties of an object. I'm currently writing an extension to package.loaders and I want to know if I need to support such behavior. Can Lua's require function return multiple results? Using == for functions only checks if they reference to the same function, which is not what you expected. (2) It is possible to create a Lua module which returns multiple results via the require function? Encapsulating logic in functions and structs - the C approach to Object Oriented techniques, Extending your bash shell with aliases, functions and extra commands, repeat until in Lua - a one or more rather than a zero or more loop. How do our tactics help us meet the strategy, for the greater good? Lua - why is string after function call allowed? Melville's chain of thought in the "great democratic God" passage in "Moby-Dick", Can someone re-license my BSD-3-licensed project under the MIT license, remove my copyright notices, and list me as a "collaborator" without consent. A number of the string functions work like this,for instance, string.find will return the start index and end index of the match, plus any captures. However, while feasible, such an implementation is wildly unsafe, as you could end up with an... You can use a subprocess to run your Lua script and provide the function with it's arguments. your coworkers to find and share information. Can Lua's require function return multiple results? Error when training the network. Several predefined functions in Lua return multiple values. I am trying to use this code for my own purposes. Does it strike you as odd that in many languages, functions can take in as many parameters as you like, but can only return one? If you're used to a language (like Python) that returns multiple values by storing them in a "tuple" type, that's not how Lua works. 3. Who "spent four years refusing to accept the validity of the [2016] election"? I would like named (string) keys. For your example:... You found a variant of the Multi-dimensional Knapsack Problem, which is known to be NP-complete. Both function calls and vararg expressions can result in multiple How to prove episodes of academic misconduct? Is it pythonic for a function to return multiple values? Both function calls and vararg expressions can result in multiple values. To learn more, see our tips on writing great answers. Also cacheing in objects and multiple catch clauses example. Multiple page web applications - maintaining state - PHP, BODMAS - the order a computer evaluates arithmetic expressions. However, even if you use hashes, random numbers, and so... Looks like a syntax error. Note that numerical codes are not necessarily portable across platforms. Coroutines in Lua. Multiple inheritance in Python - complete working example, Python - access to variables in the outer scope, Python, Tcl, Lua and other Open Source programming courses for 2018, Lua, Tcl, Python, C and C++ courses - at our Melksham HQ or on your site - forward from July 2017, Final day of training at Well House Manor - Python, Lua, Tcl and C/C++ continue at The Spa, Melksham, Programming with random numbers - yet re-using the same values for testing. How important is the gate threshold voltage on a MOSFET, Mystery game from 2000s set on an island with a bell. Lua functions actually return separate values, instead of a single container. This module and example are covered on the following public courses: Yes. Was AGP only ever used for graphics cards? Function Name− This is the actual name of the function. Here are all the parts of a method − 1. subroutine foo(c, b) character(len=:), allocatable, intent(out) :: c logical, intent(out) :: b c = 'string' b = .false. Parallel but not really parallel. Weak references in Lua - what are they, and why use them? Training, Open Source Programming Languages, Special Tcl, Expect, Tk subjects / courses. An example is the string.find function, which locates a pattern in a string. Templates in C++ - defining a family pattern of methods / functions, List slices in Python - 2 and 3 values forms, with an uplifting example, Passing parameters to Python functions - the options you have, Multiple inputs, multiple out, ruby functions, How to return 2 values from a function (C++ and C) - more uses of pointers, Using functions to keep look and feel apart from calculations - simple C example, Extra courses - Advanced PHP, MySQL and Lua, Returning multiple values from a function call in various languages - a comparison. If an expression is used as the last (or the only) This functions always returns 1 as number of returned values on stack. Georgia doing "hand recount" of 2020 Presidential Election Ballots. In Lua, can I easily select the Nth result without custom functions? This can be a surprise in some cases, for example: This happens because string.gsub returns 2 values: the given string, with occurrences of the pattern replaced, and the total number of matches that occurred. Multiple identical keys in a Python dict - yes, you can! examples in the course of their programming, but must check A single action for multiple iPad / iPhone buttons, and animation, Sharing lots of values in Tcl without having lots of global declarations. Lua functions can return multiple values, and the language will natively assign them to the variables on the other side of the equal sign. Cream teas and hotel rooms. Moving game characters. Returning multiple values from a function using an array. I use it like this: But now I have a function with multiple return values: I want to check its function by either checking it all together: but this does not work because only "1" is left on the stack for aequals. In all other contexts, Lua I still have to read the entire docs, but already found this: There are 16384 hash slots in Redis Cluster, and to compute what is the hash slot of a given key, we simply take the CRC16 of the key modulo 16384. You could swap the table and stuff() to circumvent this in a simple manner. The general form of a method definition in Lua programming language is as follows − A method definition in Lua programming language consists of a method header and a method body. How to iterate through a table in its exact order? How do I use them? Thanks for contributing an answer to Stack Overflow! For example: function triple(x) return x, x, x end When calling a function, to save these values, you must use the following syntax: local a, b, c = triple(5) Which will result in a = b = c = 5 in this case. Functions. Lua, Learning to Program in Lua - public / open training course / class, Splitting a record into individual data values in C, Returning extra results from a function in C, Refresh and Revision training class days - Perl / PHP / Python / Lua / Ruby / Tcl / C / C++, Special __ methods you can use in Lua metatables, Binary / bitwise operations in Lua with the standard bit32 library. How do I set one up? By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. 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Stack Overflow for Teams is a private, secure spot for you and I tried to fix this using the array-constructor, which supposed to make a tuple into an array/table. To subscribe to this RSS feed, copy and paste this URL into your RSS reader. Using == for functions only checks if they reference to the same function, which is not what you expected. Using a nested loop works. Since MyClass is just a lookup in the global table (_G), you could mess with its metatable's __index to return a newly-defined MyClass object (which you would later need to fill with the details).