Category: Lua function

Lua function

lua function

Lua was originally designed in as a language for extending software applications to meet the increasing demand for customization at the time. It provided the basic facilities of most procedural programming languages, but more complicated or domain-specific features were not included; rather, it included mechanisms for extending the language, allowing programmers to implement such features.

As Lua was intended to be a general embeddable extension language, the designers of Lua focused on improving its speedportabilityextensibility, and ease-of-use in development. From untilBrazil had a policy of strong trade barriers called a market reserve for computer hardware and software. In that atmosphere, Tecgraf's clients could not afford, either politically or financially, to buy customized software from abroad.

Those reasons led Tecgraf to implement the basic tools it needed from scratch. There was a lack of any flow-control structures in SOL and DEL, and Petrobras felt a growing need to add full programming power to them. In The Evolution of Luathe language's authors wrote: [5].

Inthe only real contender was Tclwhich had been explicitly designed to be embedded into applications. However, Tcl had unfamiliar syntax, did not offer good support for data description, and ran only on Unix platforms. Python was still in its infancy.

In the free, do-it-yourself atmosphere that then reigned in Tecgraf, it was quite natural that we should try to develop our own scripting language Because many potential users of the language were not professional programmers, the language should avoid cryptic syntax and semantics.

The implementation of the new language should be highly portable, because Tecgraf's clients had a very diverse collection of computer platforms.

Finally, since we expected that other Tecgraf products would also need to embed a scripting language, the new language should follow the example of SOL and be provided as a library with a C API. Lua 1. In an article published in Dr. Dobb's JournalLua's creators also state that LISP and Scheme with their single, ubiquitous data-structure mechanism the list were a major influence on their decision to develop the table as the primary data structure of Lua.

Lua semantics have been increasingly influenced by Scheme over time, [5] especially with the introduction of anonymous functions and full lexical scoping. Several features were added in new Lua versions. Versions of Lua prior to version 5. From version 5. Both are permissive free software licences and are almost identical.

Lua is commonly described as a " multi-paradigm " language, providing a small set of general features that can be extended to fit different problem types. Lua does not contain explicit support for inheritancebut allows it to be implemented with metatables. Similarly, Lua allows programmers to implement namespacesclassesand other related features using its single table implementation; first-class functions allow the employment of many techniques from functional programming ; and full lexical scoping allows fine-grained information hiding to enforce the principle of least privilege.

In general, Lua strives to provide simple, flexible meta-features that can be extended as needed, rather than supply a feature-set specific to one programming paradigm. Lua is a dynamically typed language intended for use as an extension or scripting language and is compact enough to fit on a variety of host platforms. It supports only a small number of atomic data structures such as boolean values, numbers double-precision floating point and bit integers by defaultand strings.

Typical data structures such as arrayssetslistsand records can be represented using Lua's single native data structure, the table, which is essentially a heterogeneous associative array. Lua implements a small set of advanced features such as first-class functionsgarbage collectionclosuresproper tail callscoercion automatic conversion between string and number values at run timecoroutines cooperative multitasking and dynamic module loading.

The classic "Hello, World! Multi-line strings and comments are adorned with double square brackets. The factorial function is implemented as a function in this example:. Lua has four types of loops : the while loopthe repeat loop similar to a do while loopthe numeric for loopand the generic for loop.

Lua's treatment of functions as first-class values is shown in the following example, where the print function's behavior is modified:.

[GMOD LUA] Ep. 17 Cam2D3D

Any future calls to print will now be routed through the new function, and because of Lua's lexical scopingthe old print function will only be accessible by the new, modified print.Note: This page is generated from the output of the help command in the Foldit client.

Please don't make changes to this page. Changes may be overwritten when the page is regenerated. To add details for a particular function, click on the 'Details' link for the function and add comments there. Use the 'Comments' section below for comments on this page as a whole.

Comments are preserved when the page is updated. The functions listed here are for the "V2" Foldit Lua interface. For each function, the "V1" equivalent, if any, is listed. The functions are grouped by namespace.

The absolutebest functions work with the highest-scoring pose, regardless of whether the pose is valid. For example, a pose with open cutpoints may have the highest score, but the score is not valid until the cutpoints are closed. The behavior functions control clashing importance and other properties found the client's behavior dialog and related places. The creditbest functions work with the best valid pose, in contrast to the absolutebest functions.

The puzzle functions get information about the current puzzle. They also allow the puzzle to be reset to a starting point. The recentbest functions work with the "recent best" pose. Unlike the absolutebest, creditbest, and current poses, the recentbest pose can be reset under recipe control.

The rotamer functions recipes to manipulate sidechain positions, or rotamers, of a particular segment. The scoreboard functions return information about how the current solution relative to other players. The selection functions allows segment to be selected and deselected. Many other functions only work on selected segments. The structure functions perform a variety of tasks related to specific segments of the puzzle.

lua function

Most of these tasks can also be performed manually in the client. Functions in this category do nothing. They were either never implemented, or implemented and then removed.

Sign In Don't have an account? Start a Wiki. Some of the functions which make up the Foldit Lua interface. AreConditionsMet Edit Function boolean absolutebest. AreConditionsMet Description Return whether the absolute best pose satisfies all conditions. GetEnergyScore Edit Function number absolutebest.

Lua (programming language)

GetEnergyScore Description Get the score for the absolute best pose.This is a comprehensive list of all functions that can be utilized by Lua scripting, excluding those that are part of userdata structures. In the "function" column of each table below, bolded text is the actual name of the function, text in italics represents argument types e. Unless noted otherwise, the argument names can be chosen freely; the argument names used in this article have no special meaning and are only there to simplify the explanations.

Some functions have an alternative syntax, using a different number of arguments or different argument types, for instance. These are the functions included in SRB2's math library. These are generally simple functions that are meant to be used in mathematical contexts. These are mathematical functions that are designed to be used with angles.

Some of the functions listed below can be used to convert between these two different representations. Also included here are the basic trigonometric functions sin, cos and tanwhich return values in the fixed-point scale.

These are mathematical functions that are designed to be used with fixed-point integers — i. Note: Negative values for b are not handled correctly and may slow down the game. These are simple yet specialized functions that do not fit within the base library.

Lua String Manipulation

These functions relate to the head-up displayand are all prefixed with hud. These values will automatically be adjusted by the game for other resolutions. Valid huditem string options, for the functions hud. These functions can only be used within functions hooked with hud. Note that the v prefix given to all functions listed here is adjustable — this can be any name you like, e.

Certain negative skin numbers have special effects on the colormap returned for a patch to use. They start at -1 and go to They are represented by the following constants:. RandomFixed can be used instead of v. RandomFixedif the name of the first argument in the hud. Note: a should not be larger than Otherwise, there will be only possible different results this function can return, which will be spread out across the full range given; the rest of the numbers will be skipped.

Note: The difference between a and b should not be larger than Otherwise, there will be only possible different results this function can return, which are spread out across the full range given; the rest of the numbers will be skipped. These are the functions included in SRB2's console library. Registers a console command with the name name that executes the specified function when called. The first argument of the function is the player who executed the command, and all subsequent arguments are arguments passed to the command.

Registers a console variable with the name name for use in the console and returns the console variable created. Note that no arguments are passed to the func function.

This gives each possible value listed in the table a string name of its own, which can be used in the console itself when the variable is in use. If MIN and MAX are used as string names for possible value entries, these will act as the minimum and maximum of a bounded range of possible values, allowing any value in-between the two to be picked as well.

Otherwise, the selectable values for the console variable are limited explicitly only to the possible value entries listed in the table.This is the main reference for the World of Warcraft Lua Runtime. Note that these are mostly standard Lua functions, available in most Lua environments. Arguably, we could just refer to the Lua web sitebut a few functions differ slightly in Blizzard's implementation.

They are all documented here for consistency. The World of Warcraft Lua runtime does not provide all standard Lua functions. Nearly all of these functions are part of the default Lua 5. Most of these functions are shorthand references to the Lua math library which is available via "math.

Blizzard's versions work with degrees. Lua's standard math library works with radians. These string functions are shorthand references to the Lua string library, which is available via "string.

See StringLibraryTutorial for more info. These table functions are shorthand references to the Lua table library which is available via "table. When working with any other tables behavior is not defined and might lead to unexpected results. Not being aware of this fact is one major causes for bugs in code written in Lua. World of Warcraft includes the Lua BitLib library which is available via "bit. It has been available since Patch 1. This library uses the WoW binary's native integer size.

Note: Since Lua is a scripting language, using these functions to "compress" your data structures is fairly slow work. Unless you have a very large database and need to conserve RAM usage, save your information in several, individual variables. To make this work for string constants, you have to use parentheses.

Since this uses the string table, any function placed inside the string table works the same. The following is valid:. Sign In Don't have an account? Start a Wiki. Contents [ show ]. Categories :.As part of the Unified Community Platform project, your wiki has been migrated to the new platform. Read more here. These are standard Lua functions available in most Lua parsers.

Arguably, we could just refer to the Lua web sitebut a few functions differ slightly in Blizzard's implementation. They are all documented here for consistency. These functions are part of the Lua programming language v5.

lua function

In addition to this list, see also Debugging Functions. Most of these functions are shorthand references to the Lua math library which is available via "math. Blizzard's versions work with degrees. Lua's standard math library works with radians. These string functions are shorthand references to the Lua string library which is available via "string.

These table functions are shorthand references to the Lua table library which is available via "table. When working with any other tables behavior is not defined and might lead to unexpected results. Not being aware of this fact is one major causes for bugs in code written in Lua. World of Warcraft includes the Lua bitlib library available via the "bit" table which provides access to bit manipulation operators.

It has been available since Patch 1. This library seems to work internally with standard bit 'int' values, since bit. Using these functions to pack data structures is fairly slow work.

Unless you have a very large database and need to conserve memory, save your information in several, individual variables or table fields. To make this work for string constants, you have to use parentheses.By using our site, you acknowledge that you have read and understand our Cookie PolicyPrivacy Policyand our Terms of Service.

Stack Overflow for Teams is a private, secure spot for you and your coworkers to find and share information. Learn more. Trying to make function which takes string as input and returns no. Asked today. Active today. Viewed 39 times. Dxx Dxx 11 1 1 bronze badge. New contributor. Active Oldest Votes. It matches anything inside brackets, e. Alexander Mashin Alexander Mashin 1, 5 5 silver badges 9 9 bronze badges. See the updated answer. Understood, thanks for you time Robert Robert 1 1 silver badge 10 10 bronze badges.

I want to count characters in word in whole string and string passes from the user such as user pass. I updated the answer above. I updated one more time, basically it's doing what you asked. The code is probably efficient because it does not create intermediate strings or useless data. You can read more information regarding performances, especially table. Dxx Return value as a string or a list?

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lua function

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Lua/Functions

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I am confused as to how function is declared in lua. What i want to know is the order the function definition is in the file. In my example, sample 1 works where as sample 2 wouldn't compile. In the first example, the function is defined, in another word, the variable finddir has a value of type function.

So you can call it. In the second example, the function has not been defined when you call it, in another word, the varialbe finddir has a value nilthus you can't call it. Learn more. Lua Function declaration Ask Question. Asked 6 years, 7 months ago. Active 6 years, 7 months ago. Viewed times. AlbertK AlbertK 2 2 gold badges 5 5 silver badges 15 15 bronze badges.

Active Oldest Votes. Functions in Lua are first-class values. It's not that different with other types, e. Yu Hao Yu Hao k 23 23 gold badges silver badges bronze badges. Sign up or log in Sign up using Google. Sign up using Facebook. Sign up using Email and Password. Post as a guest Name. Email Required, but never shown.

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