ଲୁଆ (ପ୍ରୋଗ୍ରାମିଂ ଭାଷା) ନିମନ୍ତେ ଆଧାର ଦେଖିବେ

{{Infobox programming language
| name                   = Lua
| logo                   = [[File:Lua-Logo.svg|128px]]
|paradigm=[[Multi-paradigm]]: [[scripting language|scripting]], [[imperative programming|imperative]] ([[procedural programming|procedural]], [[prototype-based programming|prototype-based]] [[object-oriented programming|object-oriented]]), [[functional programming|functional]]
| year                   = {{start date and age|1993}}
| designer               = [[Roberto Ierusalimschy]]<br /> Waldemar Celes<br /> Luiz Henrique de Figueiredo
| developer              =
| latest_release_version = 5.2.3
| latest_release_date    = {{Start date|2013|12|07}}
| latest_preview_version =
| latest preview date    =
| typing                 = [[Dynamic typing|dynamic]], [[Type system#Strong and weak typing|strong]], [[Duck typing|duck]]
| implementations=[http://www.lua.org/download.html Lua], [http://luajit.org/ LuaJIT], [http://code.google.com/p/llvm-lua/ LLVM-Lua], [http://code.google.com/p/lua-alchemy/ Lua Alchemy]
| programming_language = [[C (programming language)|C]]
| dialects               = [http://metalua.luaforge.net/ Metalua], [http://idle.thomaslauer.com/ Idle], [http://www.nongnu.org/gsl-shell/ GSL Shell]
| influenced_by          = [[C++]], [[CLU (programming language)|CLU]], [[Modula-2|Modula]], [[Scheme (programming language)|Scheme]], [[SNOBOL]]
| influenced=[[Io (programming language)|Io]]<!--2002-->, [[GameMonkey Script|GameMonkey]]<!--2003-->, [[Squirrel (programming language)|Squirrel]]<!--2003-->, [[Falcon (programming language)|Falcon]]<!--2003-->, [[MiniD]]<!--2006-->
| operating_system       = [[Cross-platform]]
| license                = [[MIT License]]
| website                = {{URL|http://www.lua.org/}}
| wikibooks              =
}}

'''ଲୁଆ''' ({{IPAc-en|ˈ|l|uː|ə}} {{respell|LOO|ə}}, from {{lang-pt|[[wikt:lua#Portuguese|lua]]}} {{IPA-pt|ˈlu.(w)ɐ|}} meaning ''[[moon]]''; explicitly not "LUA"<ref name=luaabout>{{cite web| url = http://www.lua.org/about.html#name| title = About Lua| publisher = Lua.org| accessdate = 2013-06-19}}</ref>) ଏକ lightweight [[ପ୍ରୋଗ୍ରାମିଂ ଭାଷା]] ଅଟେ । ଏହା ANSI Cରେ ଲେଖା ହୋଇଥିବାରୁ ବିଭିନ୍ନ ପ୍ରକାରର କମ୍ପ୍ୟୁଟରରେ ଚାଲିପାରେ ଏଣୁ ଏହାକୁ Cross-platform ସ୍କ୍ରିପ୍ଟ ଭାଷା କୁହାଯାଇପାରେ । <ref name=luaabout/> ଲୁଆର ଆପ୍ଲିକେସନ ପ୍ରୋଗ୍ରାମିଂ ଇଣ୍ଟରଫେସ ବା API [[ସି (ପ୍ରୋଗ୍ରାମିଂ ଭାଷା)|ସି]] ଅପେକ୍ଷା ସରଳ ଅଟେ ।<ref>{{cite web |url=http://www.foreignaffairs.com/articles/139332/yuri-takhteyev/from-brazil-to-wikipedia?page=2 |title=From Brazil to Wikipedia |work=[[Foreign Affairs]] |author=Yuri Takhteyev |date=April 21, 2013 |accessdate=April 25, 2013}}</ref>

== ଇତିହାସ ==
== ଫିଚର ==
=== କିଛି କୋଡ ଉଦାହରଣ === 
ଏକ ପାରମ୍ପରିକ [[hello world program|ହେଲୋ ୱାଲ୍ଡ ପ୍ରୋଗ୍ରାମ]] ନିମ୍ନୋକ୍ତ ପ୍ରକାରରେ ଲେଖା ଯାଇପାରିବ:
<syntaxhighlight lang="lua">
print('Hello World!')
</syntaxhighlight>

[[ମନ୍ତବ୍ୟ (କମ୍ପ୍ୟୁଟର ପ୍ରୋଗ୍ରାମିଂ)|ମନ୍ତବ୍ୟ]]ଗୁଡ଼ିକ ନିମ୍ନଲିଖିତ ସିଣ୍ଟାକ୍ସ ବ୍ୟବହାର କରନ୍ତି ଓ ସେସବୁ [[ଆଡ଼ା (ପ୍ରୋଗ୍ରାମିଂ ଭାଷା)|ଆଡ଼ା]], [[ଆଇଫେଲ (ପ୍ରୋଗ୍ରାମିଂ ଭାଷା)|ଇଫେଲ]], [[ହାସକେଲ (ପ୍ରୋଗ୍ରାମିଂ ଭାଷା)|ହାସକେଲ]], [[SQL]] ଏବଂ [[VHDL]] ଆଦି ସହ ସମାନ:

<syntaxhighlight lang="lua">
-- A comment in Lua starts with a double-hyphen and runs to the end of the line.

--[[ Multi-line strings & comments
     are adorned with double square brackets. ]]

--[=[ Comments like this can have other --[[comments]] nested. ]=]
</syntaxhighlight>

[[ଫାକ୍ଟୋରିଆଲ]] ଫଳନ ଏହି ଉଦାହରଣରେ ଥିବା ଗୋଟିଏ ଫଳନ ଭାବେ କାର୍ଯ୍ୟକାରୀ ହୋଇଛି:
<syntaxhighlight lang="lua">
function factorial(n)
  local x = 1
  for i = 2,n do
    x = x * i
  end
  return x
end
</syntaxhighlight>

=== ଲୁପ୍ ===
ଲୁଆ ଚାରି ପ୍ରକାରର [[loop (computing)|ଲୁପ]] ବ୍ୟବହାର କରିଥାଏ: [[while loop|<tt>ହ୍ୱାଇଲ</tt> ଲୁପ]], <tt>ରିପିଟ</tt> ଲୁପ (ଏକ [[ଡୁ ହ୍ୱାଇଲ ଲୁପ|<tt> ଡୁ ହ୍ୱାଇଲ ଲୁପ</tt> ସହ ସମାନ]]), [[for loop|<tt>ଫର</tt> ଲୁପ]], ଏବଂ ସାଧାରଣ <tt>ଫର</tt> ଲୁପ ।

<syntaxhighlight lang="lua">
--condition = true

while condition do
  --statements
end

repeat
  --statements
until condition

for i = first,last,delta do     --delta may be negative, allowing the for loop to count down or up
  print(i)
end
</syntaxhighlight>

ସାଧାରଣ <tt>ଫର</tt> ଲୁପ:

<syntaxhighlight lang="lua">
for key, value in pairs(_G) do
  print(key, value)
end
</syntaxhighlight>
ଏହା <tt>_G</tt> ସାଧାରଣ ଆଇଟିରେଟର ଫଙ୍କସନ <tt>pairs</tt> ବ୍ୟବହାର କରି ଟେବୁଲ ଉପରେ ପ୍ରକାଶ କରିବ (<tt>nil</tt> ମିଳିବା ଯାଏ) ।

=== ଫଙ୍କସନଗୁଡ଼ିକ ===
<!--
Lua's treatment of functions as [[first-class function|first-class]] values is shown in the following example, where the print function's behavior is modified:
<syntaxhighlight lang="lua">
do
  local oldprint = print
  -- Store current print function as oldprint
  function print(s)
    --[[ Redefine print function, the usual print function can still be used 
         through oldprint. The new one has only one argument.]]
    oldprint(s == "foo" and "bar" or s)
  end
end
</syntaxhighlight>
Any future calls to <tt>print</tt> will now be routed through the new function, and because of Lua's [[Scope (programming)#Lexical scoping|lexical scoping]], the old print function will only be accessible by the new, modified print.

Lua also supports [[Closure (computer science)|closures]], as demonstrated below:
<syntaxhighlight lang="lua">
function addto(x)
  -- Return a new function that adds x to the argument
  return function(y)
    --[[ When we refer to the variable x, which is outside of the current
         scope and whose lifetime would be shorter than that of this anonymous
         function, Lua creates a closure.]]
    return x + y
  end
end
fourplus = addto(4)
print(fourplus(3))  -- Prints 7
</syntaxhighlight>
A new closure for the variable <tt>x</tt> is created every time <tt>addto</tt> is called, so that each new anonymous function returned will always access its own <tt>x</tt> parameter. The closure is managed by Lua's garbage collector, just like any other object.
-->

=== ଟେବୁଲ ===
<!--
Tables are the most important data structure (and, by design, the only built-in [[composite data type]]) in Lua, and are the foundation of all user-created types. They are conceptually similar to [[associative array|associative arrays in PHP, dictionaries in Python and Hashes in Ruby or Perl]].

A table is a collection of key and data pairs, where the data is referenced by key; in other words, it's a [[hash table|hashed]] [[Heterogeneity|heterogeneous]] [[associative array]]. A key (index) can be any value but nil and [[NaN]].  A numeric key of <tt>1</tt> is considered distinct from a string key of <tt>"1"</tt>.

Tables are created using the <code>{}</code> constructor syntax:
<syntaxhighlight lang="lua">
a_table = {} -- Creates a new, empty table
</syntaxhighlight>
Tables are always passed by reference:
<syntaxhighlight lang="lua">
a_table = {x = 10}  -- Creates a new table, with one entry mapping "x" to the number 10.
print(a_table["x"]) -- Prints the value associated with the string key, in this case 10.
b_table = a_table
b_table["x"] = 20   -- The value in the table has been changed to 20.
print(b_table["x"]) -- Prints 20.
print(a_table["x"]) -- Also prints 20, because a_table and b_table both refer to the same table.
</syntaxhighlight>
-->
==== ରେକର୍ଡ଼ ଭାବେ ====
<!--
A table is often used as [[object composition|structure]] (or [[Record (computer science)|record]]) by using [[string (computer science)|strings]] as keys. Because such use is very common, Lua features a special syntax for accessing such fields.
Example:
<syntaxhighlight lang="lua">
point = { x = 10, y = 20 }   -- Create new table
print(point["x"])            -- Prints 10
print(point.x)               -- Has exactly the same meaning as line above
</syntaxhighlight>
-->
==== ନେମସ୍ପେସ ଭାବେ ====
<!--
By using a table to store related functions, it can act as a namespace.
<syntaxhighlight lang="lua">
Point = {}

Point.new = function(x, y)
  return {x = x, y = y}
end

Point.set_x = function(point, x)
  point.x = x
end
</syntaxhighlight>
-->

==== ଆରେ ଭାବେ ====
<!--
By using a numerical key, the table resembles an [[array data type]]. Lua arrays are 1-based: the first index is 1 rather than 0 as it is for many other programming languages (though an explicit index of 0 is allowed).

A simple array of strings:
<syntaxhighlight lang="lua">
array = { "a", "b", "c", "d" }   -- Indices are assigned automatically.
print(array[2])                  -- Prints "b". Automatic indexing in Lua starts at 1.
print(#array)                    -- Prints 4.  # is the length operator for tables and strings.
array[0] = "z"                   -- Zero is a legal index.
print(#array)                    -- Still prints 4, as Lua arrays are 1-based.
</syntaxhighlight>
The length of a table <math>t</math> is defined to be any integer index <math>n</math> such that <math>t[n]</math> is not <tt>nil</tt> and <math>t[n+1]</math> is <tt>nil</tt>; moreover, if <math>t[1]</math> is <tt>nil</tt>, <math>n</math> can be zero. For a regular array, with non-nil values from 1 to a given <math>n</math>, its length is exactly that <math>n</math>, the index of its last value. If the array has "holes" (that is, nil values between other non-nil values), then <tt>#t</tt> can be any of the indices that directly precedes a <tt>nil</tt> value (that is, it may consider any such nil value as the end of the array).<ref>{{cite web|url=http://www.lua.org/manual/5.1/manual.html#2.5.5|title=Lua 5.1 Reference Manual|accessdate=2012-10-16|year=2012}}</ref>
-->
<!--
An array of objects:
<syntaxhighlight lang="lua">
function Point(x, y)        -- "Point" object constructor
  return { x = x, y = y }   -- Creates and returns a new object (table)
end
array = { Point(10, 20), Point(30, 40), Point(50, 60) }   -- Creates array of points
print(array[2].y)                                         -- Prints 40
</syntaxhighlight>
Using a hash map to emulate an array normally is slower than using an actual array; however, Lua tables are optimized for use as arrays<ref name=lobject_h_array>{{cite web|url=http://www.lua.org/source/5.1/lobject.h.html#array|title=Lua 5.1 Source Code|accessdate=2011-03-24|year=2006}}</ref> to help avoid this issue.
-->

=== ମେଟାଟେବୁଲ ===
<!--
Extensible semantics is a key feature of Lua, and the [[metatable]] concept allows Lua's tables to be customized in powerful ways.  The following example demonstrates an "infinite" table.  For any <math>n</math>, <tt>fibs[n]</tt> will give the <math>n</math><sup>th</sup> [[Fibonacci number]] using [[dynamic programming]] and [[memoization]].
<syntaxhighlight lang="lua">
fibs = { 1, 1 }                                -- Initial values for fibs[1] and fibs[2].
setmetatable(fibs, {
  __index = function(values, n)                --[[ __index is a function predefined by Lua, 
                                                    it is called if key "n" does not exist. ]]
    values[n] = values[n - 1] + values[n - 2]  -- Calculate and memoize fibs[n].
    return values[n]
  end
})
</syntaxhighlight>
-->

=== ଅବଜେକ୍ଟ-ଆଧାରିତ ପ୍ରୋଗ୍ରାମିଂ ===
<!--
Although Lua does not have a built-in concept of [[class (computer science)|classes]], they can be implemented using two language features: [[first-class function]]s and tables. By placing functions and related data into a table, an object is formed. [[Inheritance (object-oriented programming)|Inheritance]] (both single and multiple) can be implemented via the [[metatable]] mechanism, telling the object to look up nonexistent methods and fields in parent object(s).

There is no such concept as "class" with these techniques; rather, [[prototype-based programming|prototypes]] are used, as in the programming languages [[Self (programming language)|Self]] or [[JavaScript]]. New objects are created either with a [[factory method pattern|factory method]] (that constructs new objects from scratch), or by cloning an existing object.

Lua provides some [[syntactic sugar]] to facilitate object orientation. To declare [[Method (computer science)|member functions]] inside a prototype table, one can use <tt>function table:func(args)</tt>, which is equivalent to <tt>function table.func(self, args)</tt>. Calling class methods also makes use of the colon: <tt>object:func(args)</tt> is equivalent to <tt>object.func(object, args)</tt>.

Creating a basic [[Vector (geometry)|vector]] object:
<syntaxhighlight lang="lua">
local Vector = {}
Vector.__index = Vector

function Vector:new(x, y, z)    -- The constructor
  return setmetatable({x = x, y = y, z = z}, Vector)
end

function Vector:magnitude()     -- Another method
  -- Reference the implicit object using self
  return math.sqrt(self.x^2 + self.y^2 + self.z^2)
end

local vec = Vector:new(0, 1, 0) -- Create a vector
print(vec:magnitude())          -- Call a method (output: 1)
print(vec.x)                    -- Access a member variable (output: 0)
</syntaxhighlight>
-->

== ସି ଆପ୍ଲିକେସନ ପ୍ରୋଗ୍ରାମିଂ ଇଣ୍ଟରଫେସ ==
ଲୂଆ ଫଙ୍କ୍‌ସନ୍‌କୁ ସି ପ୍ରୋଗ୍ରାମିଂ ଭାଷା ବ୍ୟବହାର କରି କିପରି କଲ୍ କରିହେବ ତାହାର ଏକ ଛୋଟ ଉଦାହରଣ: 
<syntaxhighlight lang="c">
#include <stdio.h>
#include <stdlib.h>
#include <lua.h>
#include <lauxlib.h>

int main(void)
{
    lua_State *L = luaL_newstate();
    if (luaL_dostring(L, "function foo (x,y) return x+y end")) {
        lua_close(L);
        exit(EXIT_FAILURE);
    }

    lua_getglobal(L, "foo");
    lua_pushinteger(L, 5);
    lua_pushinteger(L, 3);
    lua_call(L, 2, 1);
    printf("Result: %d\n", lua_tointeger(L, -1));
    lua_close(L);
    return 0;
}
</syntaxhighlight>

Running this example gives:
<pre>$ gcc -o example example.c -llua
$ ./example
Result: 8
</pre>

== ବ୍ୟବହାର ==
* [[ଭିଡିଓ ଗେମ]] ପ୍ରସ୍ତୁତକାରୀମାନଙ୍କ ପାଇଁ ଏହା ବିପୁଳ ମାତ୍ରାରେ ଆଦୃତ ସ୍କ୍ରିପ୍ଟ ଭାଷା ଅଟେ । 
== ଆହୁରି ଦେଖନ୍ତୁ ==
== ଆଧାର ==
{{ଆଧାର}}

== ଆହୁରି ପଢନ୍ତୁ ==
{{Multicol}}

=== ବହି ===
* {{Cite book | last1 = Gutschmidt | first1 = T. | title = Game Programming with Python, Lua, and Ruby | year = 2003 | publisher = Course Technology PTR | isbn = 1-59200-077-0 }}
* {{Cite book | last1 = Schuytema | first1 = P. | last2 = Manyen | first2 = M. | title = Game Development with Lua | year = 2005 | publisher = Charles River Media | isbn = 1-58450-404-8 }}
* {{Cite book | last1 = Jung | first1 = K. | last2 = Brown | first2 = A. | title = Beginning Lua Programming | year = 2007 | publisher = [[Wrox Press]] | isbn = 0-470-06917-1 | url = http://www.wrox.com/WileyCDA/WroxTitle/productCd-0470069171.html | access-date = 2014-02-22 | archive-date = 2013-10-22 | archive-url = https://web.archive.org/web/20131022235736/http://www.wrox.com/WileyCDA/WroxTitle/productCd-0470069171.html | url-status = dead }}
* {{Cite book| editor-last  = Figueiredo | editor-first  = L. H. | editor2-last = Celes | editor2-first = W. | editor3-last = Ierusalimschy | editor3-first = R. | title = Lua Programming Gems | publisher = Lua.org | year = 2008 | isbn = 978-85-903798-4-3 | url = http://www.lua.org/gems/ }}
* {{Cite book | last = Takhteyev  | first = Yuri | title = Coding Places: Software Practice in a South American City | year = 2012 | publisher = [[The MIT Press]] | isbn = 0262018071 | url = http://codingplaces.net/ }} Chapters 6 and 7 are dedicated to Lua, while others look at software in Brazil more broadly.
* {{cite book | last=Varma | first=Jayant | title=Learn Lua for iOS Game Development | publisher=[[Apress]] | year=2012 | isbn=1430246626 | url=http://www.amazon.com/exec/obidos/ASIN/1430246626/lua-docs-20 }}
* {{Cite book | last1 = Ierusalimschy | first1 = R. | title = Programming in Lua | edition = 3rd | year = 2013 | publisher = Lua.org | isbn = 85-903798-5-X | url = http://www.lua.org/pil/ }} (The 1st ed. is available [http://www.lua.org/pil/contents.html online].)
<!--UPDATEME to 5.2: * {{Cite book | last1 = Ierusalimschy | first1= R. | last2 = Figueiredo | first2 = L. H. | last3 = Celes  | first3 = W. | title = Lua 5.1 Reference Manual | year= 2006 | publisher = Lua.org | isbn= 85-903798-3-3 | url = http://www.lua.org/manual/5.1/ }}-->

{{Multicol-break}}

=== ପ୍ରବନ୍ଧ ===
* {{cite web | url=http://www.gamedev.net/page/resources/_/technical/game-programming/an-introduction-to-lua-r1932 | title=An Introduction to Lua | publisher=[[GameDev.net]] | date=29 April 2003 | accessdate=January 3, 2013 | author=Matheson, Ash | archive-date=18 December 2012 | archive-url=https://web.archive.org/web/20121218104442/http://www.gamedev.net/page/resources/_/technical/game-programming/an-introduction-to-lua-r1932 | url-status=dead }}
* {{cite web|url=http://www.onlamp.com/pub/a/onlamp/2006/02/16/introducing-lua.html|title=Introducing Lua|last=Fieldhouse|first=Keith|date=16 February 2006|work=ONLamp.com|publisher=[[O'Reilly Media]]|access-date=22 February 2014|archive-date=12 March 2006|archive-url=https://web.archive.org/web/20060312124121/http://www.onlamp.com/pub/a/onlamp/2006/02/16/introducing-lua.html|url-status=dead}}
* {{cite web|url=http://www.ibm.com/developerworks/linux/library/l-lua.html|title=Embeddable scripting with Lua|last=Streicher|first=Martin|date=28 April 2006|work=developerWorks|publisher=[[IBM]]}}
* {{cite journal |last=Quigley|first=Joseph|date=1 June 2007|title=A Look at Lua|journal=[[Linux Journal]]|url=http://www.linuxjournal.com/article/9605}}
* {{cite news|url=http://www.computerworld.com.au/article/260022/a-z_programming_languages_lua/|title=The A-Z of Programming Languages: Lua|last=Hamilton|first=Naomi|date=11 September 2008|work=[[Computerworld]]|publisher=[[IDG]]|access-date=22 February 2014|archive-date=12 June 2012|archive-url=https://web.archive.org/web/20120612025517/http://www.computerworld.com.au/article/260022/a-z_programming_languages_lua/|url-status=dead}} Interview with Roberto Ierusalimschy.
* {{cite journal |url=http://queue.acm.org/detail.cfm?id=1983083|title=Passing a Language through the Eye of a Needle|last1=Ierusalimschy|first1=Roberto|last2=de Figueiredo|first2=Luiz Henrique |last3=Celes|first3=Waldemar|date=12 May 2011|journal=[[ACM Queue]]|publisher=[[Association for Computing Machinery|ACM]]}} How the embeddability of Lua impacted its design.
* [http://www.lua.org/papers.html Lua papers and theses]
{{Multicol-end}}

== ବାହାର ଲିଙ୍କ ==
{{commons category|Lua (programming language)}}
{{wikibooks|Lua Functional Programming}}
{{Wikiversity | Lua}}
{{MediaWiki|Lua}}
* {{official website|http://www.lua.org/}}
* [http://lua-users.org lua-users.org] {{Webarchive|url=https://web.archive.org/web/20101216084624/http://lua-users.org/ |date=2010-12-16 }} – Community website for and by users (and authors) of Lua
* [http://www.eluaproject.net/en_overview.html eLua – Embedded Lua]
* [http://luaforge.net Projects in Lua]
* [http://code.google.com/p/squilu/ SquiLu Squirrel modified with Lua libraries]

{{DEFAULTSORT:Lua (Programming Language)}}
[[ଶ୍ରେଣୀ:ପ୍ରୋଗ୍ରାମିଂ ଭାଷା]]