D7net
Home
Console
Upload
information
Create File
Create Folder
About
Tools
:
/
usr
/
local
/
lp
/
sonarperl
/
man
/
man3
/
Filename :
Tie::Array.3
back
Copy
.\" -*- mode: troff; coding: utf-8 -*- .\" Automatically generated by Pod::Man 5.01 (Pod::Simple 3.43) .\" .\" Standard preamble: .\" ======================================================================== .de Sp \" Vertical space (when we can't use .PP) .if t .sp .5v .if n .sp .. .de Vb \" Begin verbatim text .ft CW .nf .ne \\$1 .. .de Ve \" End verbatim text .ft R .fi .. .\" \*(C` and \*(C' are quotes in nroff, nothing in troff, for use with C<>. .ie n \{\ . ds C` "" . ds C' "" 'br\} .el\{\ . ds C` . ds C' 'br\} .\" .\" Escape single quotes in literal strings from groff's Unicode transform. .ie \n(.g .ds Aq \(aq .el .ds Aq ' .\" .\" If the F register is >0, we'll generate index entries on stderr for .\" titles (.TH), headers (.SH), subsections (.SS), items (.Ip), and index .\" entries marked with X<> in POD. Of course, you'll have to process the .\" output yourself in some meaningful fashion. .\" .\" Avoid warning from groff about undefined register 'F'. .de IX .. .nr rF 0 .if \n(.g .if rF .nr rF 1 .if (\n(rF:(\n(.g==0)) \{\ . if \nF \{\ . de IX . tm Index:\\$1\t\\n%\t"\\$2" .. . if !\nF==2 \{\ . nr % 0 . nr F 2 . \} . \} .\} .rr rF .\" ======================================================================== .\" .IX Title "Tie::Array 3" .TH Tie::Array 3 2019-02-18 "perl v5.38.0" "Perl Programmers Reference Guide" .\" For nroff, turn off justification. Always turn off hyphenation; it makes .\" way too many mistakes in technical documents. .if n .ad l .nh .SH NAME Tie::Array \- base class for tied arrays .SH SYNOPSIS .IX Header "SYNOPSIS" .Vb 3 \& package Tie::NewArray; \& use Tie::Array; \& @ISA = (\*(AqTie::Array\*(Aq); \& \& # mandatory methods \& sub TIEARRAY { ... } \& sub FETCH { ... } \& sub FETCHSIZE { ... } \& \& sub STORE { ... } # mandatory if elements writeable \& sub STORESIZE { ... } # mandatory if elements can be added/deleted \& sub EXISTS { ... } # mandatory if exists() expected to work \& sub DELETE { ... } # mandatory if delete() expected to work \& \& # optional methods \- for efficiency \& sub CLEAR { ... } \& sub PUSH { ... } \& sub POP { ... } \& sub SHIFT { ... } \& sub UNSHIFT { ... } \& sub SPLICE { ... } \& sub EXTEND { ... } \& sub DESTROY { ... } \& \& package Tie::NewStdArray; \& use Tie::Array; \& \& @ISA = (\*(AqTie::StdArray\*(Aq); \& \& # all methods provided by default \& \& package main; \& \& $object = tie @somearray,\*(AqTie::NewArray\*(Aq; \& $object = tie @somearray,\*(AqTie::StdArray\*(Aq; \& $object = tie @somearray,\*(AqTie::NewStdArray\*(Aq; .Ve .SH DESCRIPTION .IX Header "DESCRIPTION" This module provides methods for array-tying classes. See perltie for a list of the functions required in order to tie an array to a package. The basic \fBTie::Array\fR package provides stub \f(CW\*(C`DESTROY\*(C'\fR, and \f(CW\*(C`EXTEND\*(C'\fR methods that do nothing, stub \f(CW\*(C`DELETE\*(C'\fR and \f(CW\*(C`EXISTS\*(C'\fR methods that \fBcroak()\fR if the \fBdelete()\fR or \fBexists()\fR builtins are ever called on the tied array, and implementations of \f(CW\*(C`PUSH\*(C'\fR, \f(CW\*(C`POP\*(C'\fR, \f(CW\*(C`SHIFT\*(C'\fR, \&\f(CW\*(C`UNSHIFT\*(C'\fR, \f(CW\*(C`SPLICE\*(C'\fR and \f(CW\*(C`CLEAR\*(C'\fR in terms of basic \f(CW\*(C`FETCH\*(C'\fR, \f(CW\*(C`STORE\*(C'\fR, \&\f(CW\*(C`FETCHSIZE\*(C'\fR, \f(CW\*(C`STORESIZE\*(C'\fR. .PP The \fBTie::StdArray\fR package provides efficient methods required for tied arrays which are implemented as blessed references to an "inner" perl array. It inherits from \fBTie::Array\fR, and should cause tied arrays to behave exactly like standard arrays, allowing for selective overloading of methods. .PP For developers wishing to write their own tied arrays, the required methods are briefly defined below. See the perltie section for more detailed descriptive, as well as example code: .IP "TIEARRAY classname, LIST" 4 .IX Item "TIEARRAY classname, LIST" The class method is invoked by the command \f(CW\*(C`tie @array, classname\*(C'\fR. Associates an array instance with the specified class. \f(CW\*(C`LIST\*(C'\fR would represent additional arguments (along the lines of AnyDBM_File and compatriots) needed to complete the association. The method should return an object of a class which provides the methods below. .IP "STORE this, index, value" 4 .IX Item "STORE this, index, value" Store datum \fIvalue\fR into \fIindex\fR for the tied array associated with object \fIthis\fR. If this makes the array larger then class's mapping of \f(CW\*(C`undef\*(C'\fR should be returned for new positions. .IP "FETCH this, index" 4 .IX Item "FETCH this, index" Retrieve the datum in \fIindex\fR for the tied array associated with object \fIthis\fR. .IP "FETCHSIZE this" 4 .IX Item "FETCHSIZE this" Returns the total number of items in the tied array associated with object \fIthis\fR. (Equivalent to \f(CWscalar(@array)\fR). .IP "STORESIZE this, count" 4 .IX Item "STORESIZE this, count" Sets the total number of items in the tied array associated with object \fIthis\fR to be \fIcount\fR. If this makes the array larger then class's mapping of \f(CW\*(C`undef\*(C'\fR should be returned for new positions. If the array becomes smaller then entries beyond count should be deleted. .IP "EXTEND this, count" 4 .IX Item "EXTEND this, count" Informative call that array is likely to grow to have \fIcount\fR entries. Can be used to optimize allocation. This method need do nothing. .IP "EXISTS this, key" 4 .IX Item "EXISTS this, key" Verify that the element at index \fIkey\fR exists in the tied array \fIthis\fR. .Sp The \fBTie::Array\fR implementation is a stub that simply croaks. .IP "DELETE this, key" 4 .IX Item "DELETE this, key" Delete the element at index \fIkey\fR from the tied array \fIthis\fR. .Sp The \fBTie::Array\fR implementation is a stub that simply croaks. .IP "CLEAR this" 4 .IX Item "CLEAR this" Clear (remove, delete, ...) all values from the tied array associated with object \fIthis\fR. .IP "DESTROY this" 4 .IX Item "DESTROY this" Normal object destructor method. .IP "PUSH this, LIST" 4 .IX Item "PUSH this, LIST" Append elements of LIST to the array. .IP "POP this" 4 .IX Item "POP this" Remove last element of the array and return it. .IP "SHIFT this" 4 .IX Item "SHIFT this" Remove the first element of the array (shifting other elements down) and return it. .IP "UNSHIFT this, LIST" 4 .IX Item "UNSHIFT this, LIST" Insert LIST elements at the beginning of the array, moving existing elements up to make room. .IP "SPLICE this, offset, length, LIST" 4 .IX Item "SPLICE this, offset, length, LIST" Perform the equivalent of \f(CW\*(C`splice\*(C'\fR on the array. .Sp \&\fIoffset\fR is optional and defaults to zero, negative values count back from the end of the array. .Sp \&\fIlength\fR is optional and defaults to rest of the array. .Sp \&\fILIST\fR may be empty. .Sp Returns a list of the original \fIlength\fR elements at \fIoffset\fR. .SH CAVEATS .IX Header "CAVEATS" There is no support at present for tied \f(CW@ISA\fR. There is a potential conflict between magic entries needed to notice setting of \f(CW@ISA\fR, and those needed to implement 'tie'. .SH AUTHOR .IX Header "AUTHOR" Nick Ing-Simmons <nik@tiuk.ti.com>