Free arrays software for linux

Array::Utils module contains small utils for array manipulation.

SYNOPSIS

use Array::Utils qw(:all);

my @a = qw( a b c d );
my @b = qw( c d e f );

# symmetric difference
my @diff = array_diff(@a, @b);

# intersection
my @isect = intersect(@a, @b);

# unique union
my @unique = unique(@a, @b);

# check if arrays contain same members

if ( !array_diff(@a, @b) ) {
# do something
}

FUNCTIONS

unique

Returns an array of unique items in the arguments list.

intersect

Returns an intersection of two arrays passed as arguments.

array_diff

Return symmetric difference of two arrays passed as arguments

JavaArray is a tied extension for Java arrays from Java.pm

SYNOPSIS

use Java;

# Set up Java.pm to always return tied array references to me
my $java = new Java(use_tied_arrays => 1);
my $tied_array = $java->create_array("java.lang.String",5);

OR

# Roll my own tied arrays
my @tied_array;
tie @tied_array, JavaArray, $java->create_array("java.lang.String",5);
OR
tie @tied_array, JavaArray, $some_object_that_is_an_array;

// Set array element 3 to "Java is lame"
$tied_array[3] = "Java is lame";

// Get array element 3s value
my $element = $tied_array[3]->get_value();

// Get length
my $length = scalar(@tied_array);
my $size = $#tied_array;

// Use as parameter you gotta pass the reference!
my $list = $java->java_util_Arrays("asList",@tied_array);

// NO OTHER ARRAY OPERATIONS ARE AVAILABLE!
// so no pop or push or unshift or shift or splice
// Hey even this cant make Java arrays cool!
// use the Collections framework!

This module puts a pretty thin veneer over Java.pm objects are are Java arrays. Makes em slightly prettier to play with. You can pass as an agrument to the tie any Java object that is an array - either one you created yourself or one that was returned to you by something else.

You probably should NOT be using this directly, but specify use_tied_arrays in your constructor args to Java.pm.

In parameter lists

If you want to use your array in a parameter list youve got to pass in the REFERENCE to your array or things will go haywire... If you specified use_tied_arrays in your Java.pm constructor then you will only receive references back from Java.pm so youve already got the reference. ONLY if you call tie yourself (& I cant really think of why you ever would... BUT) & get the array itself do you need to take its reference when using it in parameter lists.

Automatic usage

You can tell Java.pm to automatically convert all Java arrays to their tied counterparts by setting use_tied_arrays in your Java constructor. You will get receive a reference to the tied array so you must use the -> notation like:

$array->[3] = "Mark rox";
my $ele = $array->[4];

See perldoc Java.pm for more info. You can then use that value directly in parameter lists.

Set::Array Perl module contains arrays as objects with lots of handy methods (including Set comparisons) and support for method chaining.

SYNOPSIS

my $sao1 = Set::Array->new(1,2,4,"hello",undef);
my $sao2 = Set::Array->new(qw(a b c a b c));
print $sao1->length; # prints 5
$sao2->unique->length->print; # prints 3

Set::Array allows you to create arrays as objects and use OO-style methods on them. Many convenient methods are provided here that appear in the FAQs, the Perl Cookbook or posts from comp.lang.perl.misc. In addition, there are Set methods with corresponding (overloaded) operators for the purpose of Set comparison, i.e. +, ==, etc.

The purpose is to provide built-in methods for operations that people are always asking how to do, and which already exist in languages like Ruby. This should (hopefully) improve code readability and/or maintainability. The other advantage to this module is method-chaining by which any number of methods may be called on a single object in a single statement.

OBJECT BEHAVIOR

The exact behavior of the methods depends largely on the calling context.
Here are the rules:

* If a method is called in void context, the object itself is modified.
* If the method called is not the last method in a chain (i.e. its called in object context), the object itself is modified by that method regardless of the final context or method call.
* If a method is called in list or scalar context, a list or list refererence is returned, respectively. The object itself is NOT modified.

Heres a quick example:

my $sao = Set::Array->new(1,2,3,2,3);
my @uniq = $sao->unique(); # Object unmodified. @uniq contains 3 values.
$sao->unique(); # Object modified, now contains 3 values

Here are the exceptions:

* Methods that report a value, such as boolean methods like exists() or other methods such as at() or as_hash(), never modify the object.
* The methods clear(), delete(), delete_at(), and splice will always modify the object. It seemed much too counterintuitive to call these methods in any context without actually deleting/clearing/substituting the items!
* The methods shift() and pop() will modify the object AND return the value that was shifted or popped from the array. Again, it seemed much too counterintuitive for something like $val = $sao->shift to return a value while leaving the objects list unchanged. If you really want the first or last value without modifying the object, you can always use the first() or last() method, respectively.
* The join() method always returns a string and is really meant for use in conjunction with the print() method.

BOOLEAN METHODS

exists(val) - Returns 1 if val exists within the array, 0 otherwise. If no value (or undef) is passed, then this method will test for the existence of undefined values within the array.
is_empty() - Returns 1 if the array is empty, 0 otherwise. Empty is defined as having a length of 0.

STANDARD METHODS

at(index) - Returns the item at the given index (or undef). A negative index may be used to count from the end of the array. If no value (or undef) is specified, it will look for the first item that is not defined.

clear() - Empties the array (i.e. length becomes 0). You may pass a 1 to this method to set each element of the array to undef rather than truly empty it.

compact() - Removes undefined elements from the array.

count(?val?) - Returns the number of instances of val within the array. If val is not specified (or is undef), the method will return the number of undefined values within the array.

delete(list) - Deletes all items within list from the array that match. This method will crash if list is not defined. If your goal is to delete undefined values from your object, use the compact() method instead.

delete_at(index, ?index?) - Deletes the item at the specified index. If a second index is specified, a range of items is deleted. You may use -1 or the string end to refer to the last element of the array.

duplicates - Returns a list of N-1 elements for each element N in the set. For example, if you have set "X X Y Y Y", this method would return a the list "X Y Y".

fill(val,?start?,?length?) - Sets the selected elements of the array (which may be the entire array) to val. The default value for start is 0. If length is not specified the entire array, however long it may be at the time of the call, will be filled. Alternatively, a quoted integer range may be used.

e.g. $sao->fill(x,3-5);

The array length/size may not be expanded with this call - it is only meant to fill in already-existing elements.

first() - Returns the first element of the array (or undef).

flatten() - Causes a one-dimensional flattening of the array, recursively. That is, for every element that is an array (or hash, or a ref to either an array or hash), extract its elements into the array.

e.g. my $sa = Set::Array->new([1,3,2],{one=>a,two=>b},x,y,z);

$sao->flatten->join(,)->print; # prints "1,3,2,one,a,two,b,x,y,z"

foreach(sub ref) - Iterates over an array, executing the subroutine for each element in the array. If you wish to modify or otherwise act directly on the contents of the array, use $_ within your sub reference.

e.g. To increment all elements in the array by one...

$sao->foreach(sub{ ++$_ });

get - Alias for the indices() method.

index(val) - Returns the index of the first element of the array object that contains val. Returns undef if no value is found.

Note that there is no dereferencing here so if youre looking for an item nested within a ref, use the flatten method first.

indices(val1,?val2?, ?val...?) - Returns an array consisting of the elements at the specified indices or undef if the element is out of range.

A range may also be used. It must be a quoted string in 0..3 format.

join(?char?) - Joins the individual elements of the list into a single string with the elements separated by the value of char. Useful in conjunction with the print() method. If no character is specified, then char defaults to a comma.

e.g. $sao->join(-)->print;

last() - Returns the last element of the array (or undef).

length() - Returns the number of elements within the array.

max() - Returns the maximum value of an array. No effort is made to check for non-numeric data.

pack(template) - Packs the contents of the array into a string (in scalar context) or a single array element (in object or void context).

pop() - Removes the last element from the array. Returns the popped element.

print(?1?) - Prints the contents of the array. If a 1 is provided as an argument, the output will automatically be terminated with a newline.

This also doubles as a contents method, if you just want to make a copy of the array, e.g. my @copy = $sao->print;

Can be called in void or list context, e.g.

$sao->print(); # or... print "Contents of array are: ", $sao->print();

push(list) - Adds list to the end of the array, where list is either a scalar value or a list. Returns an array or array reference in list or scalar context, respectively. Note that it does not return the length in scalar context. Use the length method for that.

reverse() - Reverses the order of the contents of the array.

rindex(val) - Similar to the index() method, except that it returns the index of the last val found within the array.

set(index,value) - Sets the element at index to value, replacing whatever may have already been there.

shift() - Shifts the first element of the array and returns the shifted element.

sort(?coderef?) - Sorts the contents of the array in alphabetical order, or in the order specified by the optional coderef. Use your standard $a and $b variables within your calling program, e.g:

my $sao = Set::Array->new( { name => Berger, salary => 20000 }, { name => Berger, salary => 15000 }, { name => Vera, salary => 25000 }, );
my $subref = sub{ $b->{name} cmp $a->{name} || $b->{salary} $a->{salary} };
$sao14->sort($subref)->flatten->join->print(1);

splice(?offset?,?length?,?list?) - Splice the array starting at position offset up to length elements, and replace them with list. If no list is provided, all elements are deleted. If length is omitted, everything from offset onward is removed.

Returns an array or array ref in list or scalar context, respectively. This method always modifies the object, regardless of context. If your goal was to grab a range of values without modifying the object, use the indices method instead.

unique() - Removes/returns non-unique elements from the list.

unshift(list) - Prepends a scalar or list to array. Note that this method returns an array or array reference in list or scalar context, respectively. It does not return the length of the array in scalar context. Use the length method for that.

ODDBALL METHODS

as_hash() - Returns a hash based on the current array, with each even numbered element (including 0) serving as the key, and each odd element serving as the value. This can be switched by using the key_order option and setting it to odd, in which case the even values serve as the values, and the odd elements serve as the keys. The default is even.

Of course, if you dont care about insertion order, you could just as well do something like, $sao-reverse->as_hash;>

Carp::croaks if the array contains an odd number of elements. This method does not actually modify the object itself in any way. It just returns a plain hash in list context or a hash reference in scalar context. The reference is not blessed, therefore if this method is called as part of a chain, it must be the last method called.

impose(?append/prepend?,string) - Appends or prepends the specified string to each element in the array. Specify the method by using either the keyword append or prepend. The default is append.

randomize() - Randomizes the order of the elements within the array.

rotate(direction) - Moves the last item of the list to the front and shifts all other elements one to the right, or vice-versa, depending on what you pass as the direction - ftol (first to last) or ltof (last to first). The default is ltof.

e.g. my $sao = Set::Array->new(1,2,3);

$sao->rotate(); # order is now 3,1,2

$sao->rotate(ftol); # order is back to 1,2,3

SYNOPSIS

use Array::Compare;

my $comp1 = Array::Compare->new;
$comp->Sep(|);
$comp->Skip({3 => 1, 4 => 1});
$comp->WhiteSpace(0);
$comp->Case(1);

my $comp2 = Array::Compare->new(Sep => |,
WhiteSpace => 0,
Case => 1,
Skip => {3 => 1, 4 => 1});

my @arr1 = 0 .. 10;
my @arr2 = 0 .. 10;

$comp1->compare(@arr1, @arr2);
$comp2->compare(@arr1, @arr2);

If you have two arrays and you want to know if they are the same or different, then Array::Compare will be useful to you.
All comparisons are carried out via a comparator object. In the simplest usage, you can create and use a comparator object like this:

my @arr1 = 0 .. 10;
my @arr2 = 0 .. 10;

my $comp = Array::Compare->new;

if ($comp->compare(@arr1, @arr2)) {
print "Arrays are the samen";
} else {
print "Arrays are differentn";
}

Notice that you pass references to the two arrays to the comparison method.

Internally the comparator compares the two arrays by using join to turn both arrays into strings and comparing the strings using eq. In the joined strings, the elements of the original arrays are separated with the ^G character. This can cause problems if your array data contains ^G characters as it is possible that two different arrays can be converted to the same string.

To avoid this, it is possible to override the default separator character, either by passing and alternative to the new function

my $comp = Array::Compare->new(Sep => |);

or by changing the seperator for an existing comparator object

$comp->Sep(|);

In general you should choose a separator character that wont appear in your data.

You can also control whether or not whitespace within the elements of the arrays should be considered significant when making the comparison. The default is that all whitespace is significant. The alternative is for all consecutive white space characters to be converted to a single space for the pruposes of the comparison. Again, this can be turned on when creating a comparator object:

my $comp = Array::Compare->new(WhiteSpace => 0);

or by altering an existing object:

$comp->WhiteSpace(0);

You can also control whether or not the case of the data is significant in the comparison. The default is that the case of data is taken into account. This can be changed in the standard ways when creating a new comparator object:

my $comp = Array::Compare->new(Case => 0);

or by altering an existing object:

$comp->Case(0);

In addition to the simple comparison described above (which returns true if the arrays are the same and false if theyre different) there is also a full comparison which returns a list containing the indexes of elements which differ between the two arrays. If the arrays are the same it returns an empty list. In scalar context the full comparison returns the length of this list (i.e. the number of elements that differ). You can access the full comparision in two ways. Firstly, there is a DefFull attribute. If this is true then a full comparison if carried out whenever the compare method is called.

my $comp = Array::Compare->new(DefFull => 1);
$comp->compare(@arr1, @arr2); # Full comparison

$comp->DefFull(0);
$comp->compare(@arr1, @arr2); # Simple comparison

$comp->DefFull(1);
$comp->compare(@arr1, @arr2); # Full comparison again

Secondly, you can access the full comparison method directly

$comp->full_compare(@arr1, @arr2);

For symmetry, there is also a direct method to use to call the simple comparison.

$comp->simple_compare(@arr1, @arr2);

The final complication is the ability to skip elements in the comparison. If you know that two arrays will always differ in a particular element but want to compare the arrays ignoring this element, you can do it with Array::Compare without taking array slices. To do this, a comparator object has an optional attribute called Skip which is a reference to a hash. The keys in this hash are the indexes of the array elements and the values should be any true value for elements that should be skipped.

For example, if you want to compare two arrays, ignoring the values in elements two and four, you can do something like this:

my %skip = (2 => 1, 4 => 1);
my @a = (0, 1, 2, 3, 4, 5);
my @b = (0, 1, X, 3, X, 5);

my $comp = Array::Compare->new(Skip => %skip);

$comp->compare(@a, @b);

This should return true, as we are explicitly ignoring the columns which differ.

Of course, having created a comparator object with no skip hash, it is possible to add one later:

$comp->Skip({1 => 1, 2 => 1});

or:

my %skip = (1 => 1, 2 => 2);
$comp->Skip(%skip);

To reset the comparator so that no longer skips elements, set the skip hash to an empty hash.

$comp->Skip({});

You can also check to see if one array is a permutation of another, i.e. they contain the same elements but in a different order.

if ($comp->perm(@a, @b) {
print "Arrays are permsn";
else {
print "Nope. Arrays are completely differentn";
}

In this case the values of WhiteSpace and Case are still used, but Skip is ignored for, hopefully, obvious reasons.

Array::Iterator is a simple class for iterating over Perl arrays.

SYNOPSIS

use Array::Iterator;

# create an iterator with an array
my $i = Array::Iterator->new(1 .. 100);

# create an iterator with an array reference
my $i = Array::Iterator->new(@array);

# create an iterator with a hash reference
my $i = Array::Iterator->new({ __array__ => @array });

# a base iterator example
while ($i->hasNext()) {
if ($i->peek() < 50) {
# ... do something because
# the next element is over 50
}
my $current = $i->next();
# ... do something with current
}

# shortcut style
my @accumulation;
push @accumulation => { item => $iterator->next() } while $iterator->hasNext();

# C++ ish style iterator
for (my $i = Array::Iterator->new(@array); $i->hasNext(); $i->next()) {
my $current = $i->current();
# .. do something with current
}

# common perl iterator idiom
my $current;
while ($current = $i->getNext()) {
# ... do something with $current
}

This class provides a very simple iterator interface. It is is uni-directional and can only be used once. It provides no means of reverseing or reseting the iterator. It is not recommended to alter the array during iteration, however no attempt is made to enforce this (although I will if I can find an efficient means of doing so). This class only intends to provide a clear and simple means of generic iteration, nothing more (yet).

Tie::CharArray module can access Perl scalars as arrays of characters.

SYNOPSIS

use Tie::CharArray;
my $foobar = a string;

tie my @foo, Tie::CharArray, $foobar;
$foo[0] = A; # $foobar = A string
push @foo, !; # $foobar = A string!
print "@foon"; # prints: A s t r i n g !

tie my @bar, Tie::CharArray::Ord, $foobar;
$bar[0]--; # $foobar = @ string!
pop @bar; # $foobar = @ string
print "@barn"; # prints: 64 32 115 116 114 105 110 103
Alternative interface functions
use Tie::CharArray qw( chars codes );
my $foobar = another string;

my $chars = chars $foobar; # arrayref in scalar context
push @$chars, ?; # $foobar = another string?

$_ += 2 for codes $foobar; # tied array in list context
# $foobar = cpqvjgt"uvtkpiA

my @array = chars $foobar; # WARNING: @array isnt tied!

In low-level programming languages such as C, and to some extent Java, strings are not primitive data types but arrays of characters, which in turn are treated as integers. This closely matches the internal representation of strings in the memory.

Perl, on the other hand, abstracts such internal details away behind the concept of scalars, which can be treated as either strings or numbers, and appear as primitive types to the programmer. This often better matches the way people think about the data, which facilitates programming by making common high-level manipulation tasks trivial.

Sometimes, though, the low-level view is better suited for the task at hand. Perl does offer functions such as ord()/chr(), pack()/unpack() and substr() that can be used to solve such tasks with reasonable efficiency. For someone used to the direct access to the internal representation offered by other languages, however, these functions may feel awkward. While this is often only a symptom of thinking in un-Perlish terms, sometimes being able to manipulate strings as character arrays really does simplify the code, making the intent more obvious by eliminating syntactic clutter.

This module provides a way to manipulate Perl strings through tied arrays. The operations are implemented in terms of the aforementioned string manipulation functions, but the programmer normally need not be aware of this. As Perl has no primitive character type, two alternative representations are provided:

AJASON is a PHP 5 library and JavaScript client for the upcoming Web technology called AJAX. AJAX permits data to be fetched asynchronously without the need for reloading the Web page and thus allows the development of interactive GUI-like Web applications.
JSON is a lightweight data interchange format which is used by AJASON to exchange data between server and client.
Main features:
- Fully object oriented code in PHP 5 and JavaScript
- Call PHP functions and object methods from JavaScript asynchronously
- Exchange even complex data types like arrays and objects (precisely object properties) between server and client
- Use JavaScript callback functions to process server responses
- Client side error reporting for server side AJASON errors
- Open source released under the GNU GPL