Download Shareware and Freeware Software for Windows, Linux, Macintosh, PDA

line Home  |  About Us  |  Link To Us  |  FAQ  |  Contact

Serving Software Downloads in 976 Categories, Downloaded 30.153.874 Times

SelfLoader 5.8.8

  Date Added: June 08, 2010  |  Visits: 433

SelfLoader

Report Broken Link
Printer Friendly Version


Product Homepage
Download (71 downloads)

SelfLoader is a Perl module created to load functions only on demand. SYNOPSIS package FOOBAR; use SelfLoader; ... (initializing code) __DATA__ sub {.... This module tells its users that functions in the FOOBAR package are to be autoloaded from after the __DATA__ token. See also "Autoloading" in perlsub. The __DATA__ token The __DATA__ token tells the perl compiler that the perl code for compilation is finished. Everything after the __DATA__ token is available for reading via the filehandle FOOBAR::DATA, where FOOBAR is the name of the current package when the __DATA__ token is reached. This works just the same as __END__ does in package main, but for other modules data after __END__ is not automatically retrievable, whereas data after __DATA__ is. The __DATA__ token is not recognized in versions of perl prior to 5.001m. Note that it is possible to have __DATA__ tokens in the same package in multiple files, and that the last __DATA__ token in a given package that is encountered by the compiler is the one accessible by the filehandle. This also applies to __END__ and main, i.e. if the main program has an __END__, but a module required (_not_ used) by that program has a package main; declaration followed by an __DATA__, then the DATA filehandle is set to access the data after the __DATA__ in the module, _not_ the data after the __END__ token in the main program, since the compiler encounters the required file later. SelfLoader autoloading The SelfLoader works by the user placing the __DATA__ token after perl code which needs to be compiled and run at require time, but before subroutine declarations that can be loaded in later - usually because they may never be called. The SelfLoader will read from the FOOBAR::DATA filehandle to load in the data after __DATA__, and load in any subroutine when it is called. The costs are the one-time parsing of the data after __DATA__, and a load delay for the _first_ call of any autoloaded function. The benefits (hopefully) are a speeded up compilation phase, with no need to load functions which are never used. The SelfLoader will stop reading from __DATA__ if it encounters the __END__ token - just as you would expect. If the __END__ token is present, and is followed by the token DATA, then the SelfLoader leaves the FOOBAR::DATA filehandle open on the line after that token. The SelfLoader exports the AUTOLOAD subroutine to the package using the SelfLoader, and this loads the called subroutine when it is first called. There is no advantage to putting subroutines which will _always_ be called after the __DATA__ token. Autoloading and package lexicals A my $pack_lexical statement makes the variable $pack_lexical local _only_ to the file up to the __DATA__ token. Subroutines declared elsewhere _cannot_ see these types of variables, just as if you declared subroutines in the package but in another file, they cannot see these variables. So specifically, autoloaded functions cannot see package lexicals (this applies to both the SelfLoader and the Autoloader). The vars pragma provides an alternative to defining package-level globals that will be visible to autoloaded routines. See the documentation on vars in the pragma section of perlmod. SelfLoader and AutoLoader The SelfLoader can replace the AutoLoader - just change use AutoLoader to use SelfLoader (though note that the SelfLoader exports the AUTOLOAD function - but if you have your own AUTOLOAD and are using the AutoLoader too, you probably know what youre doing), and the __END__ token to __DATA__. You will need perl version 5.001m or later to use this (version 5.001 with all patches up to patch m). There is no need to inherit from the SelfLoader. The SelfLoader works similarly to the AutoLoader, but picks up the subs from after the __DATA__ instead of in the lib/auto directory. There is a maintenance gain in not needing to run AutoSplit on the module at installation, and a runtime gain in not needing to keep opening and closing files to load subs. There is a runtime loss in needing to parse the code after the __DATA__. Details of the AutoLoader and another view of these distinctions can be found in that modules documentation. __DATA__, __END__, and the FOOBAR::DATA filehandle. This section is only relevant if you want to use the FOOBAR::DATA together with the SelfLoader. Data after the __DATA__ token in a module is read using the FOOBAR::DATA filehandle. __END__ can still be used to denote the end of the __DATA__ section if followed by the token DATA - this is supported by the SelfLoader. The FOOBAR::DATA filehandle is left open if an __END__ followed by a DATA is found, with the filehandle positioned at the start of the line after the __END__ token. If no __END__ token is present, or an __END__ token with no DATA token on the same line, then the filehandle is closed. The SelfLoader reads from wherever the current position of the FOOBAR::DATA filehandle is, until the EOF or __END__. This means that if you want to use that filehandle (and ONLY if you want to), you should either 1. Put all your subroutine declarations immediately after the __DATA__ token and put your own data after those declarations, using the __END__ token to mark the end of subroutine declarations. You must also ensure that the SelfLoader reads first by calling SelfLoader->load_stubs();, or by using a function which is selfloaded; or 2. You should read the FOOBAR::DATA filehandle first, leaving the handle open and positioned at the first line of subroutine declarations. You could conceivably do both. Classes and inherited methods. For modules which are not classes, this section is not relevant. This section is only relevant if you have methods which could be inherited. A subroutine stub (or forward declaration) looks like sub stub; i.e. it is a subroutine declaration without the body of the subroutine. For modules which are not classes, there is no real need for stubs as far as autoloading is concerned. For modules which ARE classes, and need to handle inherited methods, stubs are needed to ensure that the method inheritance mechanism works properly. You can load the stubs into the module at require time, by adding the statement SelfLoader->load_stubs(); to the module to do this. The alternative is to put the stubs in before the __DATA__ token BEFORE releasing the module, and for this purpose the Devel::SelfStubber module is available. However this does require the extra step of ensuring that the stubs are in the module. If this is done I strongly recommend that this is done BEFORE releasing the module - it should NOT be done at install time in general. Multiple packages and fully qualified subroutine names Subroutines in multiple packages within the same file are supported - but you should note that this requires exporting the SelfLoader::AUTOLOAD to every package which requires it. This is done automatically by the SelfLoader when it first loads the subs into the cache, but you should really specify it in the initialization before the __DATA__ by putting a use SelfLoader statement in each package. Fully qualified subroutine names are also supported. For example, __DATA__ sub foo::bar {23} package baz; sub dob {32} will all be loaded correctly by the SelfLoader, and the SelfLoader will ensure that the packages foo and baz correctly have the SelfLoader AUTOLOAD method when the data after __DATA__ is first parsed..

Requirements: No special requirements
Platforms: Linux
Keyword: Autoload Autoloader Data End Filehandle Foobar Libraries Load Module Package Perl Module Selfloader Subroutine Token You Want To
Users rating: 0/10

License: Freeware Size: 12.2 MB
SELFLOADER RELATED
Libraries  -  Image::Xpm 1.09
Image::Xpm is a Perl module that can load, create, manipulate and save xpm image files. SYNOPSIS use Image::Xpm; my $j = Image::Xpm->new(-file, Camel.xpm); my $i = Image::Xpm->new(-width => 10, -height => 16); my $h = $i->new; # Copy of...
102.4 KB  
Libraries  -  XML::TiePYX 0.05
XML::TiePYX is a Perl module to read or write XML data in PYX format via tied filehandle SYNOPSIS use XML::TiePYX; tie *XML,XML::TiePYX,file.xml open IN,file.xml or die $!; tie *XML,XML::TiePYX,*IN,Condense=>0; my $text=< tag...
7.17 KB  
Libraries  -  Test::Data 1.20
Test::Data is a Perl module to test functions for particular variable types. SYNOPSIS use Test::Data qw(Scalar Array Hash Function); Test::Data provides utility functions to check properties and values of data and variables. Functions...
8.19 KB  
Libraries  -  Data::Inherited 1.00
Data::Inherited is a Perl module with hierarchy-wide accumulation of list and hash results. SYNOPSIS package Foo; use base Data::Inherited; use constant PROPERTIES => (qw/name address/); package Bar; use base Foo; use constant PROPERTIES...
12.29 KB  
Libraries  -  Catalyst::Plugin::Dumper 0.000002
Catalyst::Plugin::Dumper is a Perl module with Data::Dumper plugin for Catalyst. SYNOPSIS use Catalyst qw/-Debug Dumper/; $c->log->dumper($myvar); $c->log->dumper($myvar, mylabel); This plugin injects a dumper() method into the...
4.1 KB  
Utilities  -  THC-ManipulateData 1.3
THC-ManipulateData can search data on a harddisk/partition/file, extract the part you are interested in, and write it back after you modified it. Useful to find and modify really all unencrypted Logfiles on a system. Does everything in RAW mode,...
7.17 KB  
Multimedia & Graphics  -  Advanced Roots Calculator New
Advanced Roots Calculator is a small, simple, command prompt based application specially designed to help you choose what kind of root of a number or data arithmetic you want to calculate. for WindowsAll
 
Database Tools  -  Orabbix 1.2.2
Orabbix is a handy, easy to use tool specially designed to help you monitor oracle instances with zabbix, with this you are going to acquire data from every oracle instances that you want to monitor and then zabbix server is going to produce...
 
Audio Tools  -  AmoK Playlist Copy 2.1
Probably you know the scenario: You have a playlist (Winamp, Windows Media Player, iTunes or Foobar) with your favourite music but as soon as you want to copy files from the playlist to an MP3-Player, an USB stick or burn them on a CD, you get a...
709 KB  
Games  -  End of the World - 3rd Planet Space Mission 1.0
Is the end of the world and your mission if you want to accept it is to defend the world with .... mmm with ...... your finger! tons of meteors are landing on earth and we need a fast finger commander that can stop...
22 MB  
NEW DOWNLOADS IN PROGRAMMING, LIBRARIES
Programming  -  FLEX-db Digital Asset Manager 3.0.9
FLEX-db - an enterprise Digital Asset Manager (DAM). It ingests and links metadata with files, creates thumbnails, and processes files using business rules. FLEX-db has a JSP client, Java app server for file input and output and an EJB metadata...
21.57 MB  
Programming  -  Libicom 0.9.0
The libicom library is a character based dynamicly linked library for Linux. It is used to remotely control the Icom IC-R8500 wide band receiver via an RS232 link. All call and return parameters to the control functions are character string based....
20.48 KB  
Programming  -  dotdesktop 0.3
Dotdesktop library provides ability to parse desktop entry file and access the information in a convenient way. Desktop entry file format is defined by freedesktop.org, it is used to describe information about an application such as the name and...
327.68 KB  
Programming  -  Cedalion for Linux 0.2.6
Cedalion is a programming language that allows its users to add new abstractions and define (and use) internal DSLs. Its innovation is in the fact that it uses projectional editing to allow the new abstractions to have no syntactic limitations.
471.04 KB  
Programming  -  libyasl 0.2
Libyasl is a C++ class library to easily realize TCP/UDP/Multicast clientsand servers in IPv4 and IPv6 environments under GNU/Linux systems.
143.36 KB  
Libraries  -  wolfSSL 3.12.0
The wolfSSL embedded SSL/TLS library is a lightweight SSL library written in ANSI standard C and targeted for embedded and RTOS environments - primarily because of its small size, speed, and feature set. It is commonly used in standard operating...
2.73 MB  
Libraries  -  EuGTK 4.8.9
Makes it easy to develop good- looking, fast, cross-platform programs that run on Linux, OS X, and Windows. Euphoria is a very fast interpreted/compiled language with straight-forward syntax. EuGTK allows programming in a clean, object-oriented...
10.68 MB  
Libraries  -  Linux User Group Library Manager 1.0
The LUG Library Manager is a project to help Linux User Groups start their own library. A LUG library is helpful to the community at large because it increases access to information, and gives everyone the opportunity to become more knowledgeable.
5.35 KB  
Libraries  -  Module::MakefilePL::Parse 0.12
Module::MakefilePL::Parse is a Perl module to parse required modules from Makefile.PL. SYNOPSIS use Module::MakefilePL::Parse; open $fh, Makefile.PL; $parser = Module::MakefilePL::Parse->new( join("", ) ); $info = $parser->required;...
8.19 KB  
Libraries  -  sqlpp 0.06
sqlpp Perl package is a SQL preprocessor. sqlpp is a conventional cpp-alike preprocessor taught to understand SQL ( PgSQL, in particular) syntax specificities. In addition to the standard #define/#ifdef/#else/#endif cohort, provides also...
10.24 KB