# create String objects via USE directive [% USE String %] [% USE String 'initial text' %] [% USE String text => 'initial text' %] # or from an existing String via new() [% newstring = String.new %] [% newstring = String.new('newstring text') %] [% newstring = String.new( text => 'newstring text' ) %] # or from an existing String via copy() [% newstring = String.copy %] # append text to string [% String.append('text to append') %] # format left, right or center/centre padded [% String.left(20) %] [% String.right(20) %] [% String.center(20) %] # American spelling [% String.centre(20) %] # European spelling # and various other methods...
This module implements a String class for doing stringy
things to text in an object-oriented way.
You can create a String object via the USE
directive, adding any initial text value as an argument or as the named
parameter text.
[% USE String %] [% USE String 'initial text' %] [% USE String text='initial text' %]
The object created will be referenced as String by default,
but you can provide a different variable name for the object to be
assigned to:
[% USE greeting = String 'Hello World' %]
Once you've got a String object, you can use it as a
prototype to create other String objects with the
new() method.
[% USE String %] [% greeting = String.new('Hello World') %]
The new() method also accepts an initial text string as an
argument or the named parameter text.
[% greeting = String.new( text => 'Hello World' ) %]
You can also call copy() to create a new String
as a copy of the original.
[% greet2 = greeting.copy %]
The String object has a text() method to return
the content of the string.
[% greeting.text %]
However, it is sufficient to simply print the string and let the
overloaded stringification operator call the text() method
automatically for you.
[% greeting %]
Thus, you can treat String objects pretty much like any
regular piece of text, interpolating it into other strings, for example:
[% msg = "It printed '$greeting' and then dumped core\n" %]
You also have the benefit of numerous other methods for manipulating the string.
[% msg.append("PS Don't eat the yellow snow") %]
Note that all methods operate on and mutate the contents of the string itself. If you want to operate on a copy of the string then simply take a copy first:
[% msg.copy.append("PS Don't eat the yellow snow") %]
These methods return a reference to the String object
itself. This allows you to chain multiple methods together.
[% msg.copy.append('foo').right(72) %]
It also means that in the above examples, the String is
returned which causes the text() method to be called, which
results in the new value of the string being printed. To suppress
printing of the string, you can use the CALL directive.
[% foo = String.new('foo') %] [% foo.append('bar') %] # prints "foobar" [% CALL foo.append('bar') %] # nothing
These methods are used to create new String objects.
Creates a new string using an initial value passed as a positional
argument or the named parameter text.
[% USE String %] [% msg = String.new('Hello World') %] [% msg = String.new( text => 'Hello World' ) %]
Creates a new String object which contains a copy of the
original string.
[% msg2 = msg.copy %]
These methods are used to examine the string.
Returns the internal text value of the string. The stringification operator is overloaded to call this method. Thus the following are equivalent:
[% msg.text %] [% msg %]
Returns the length of the string.
[% USE String("foo") %] [% String.length %] # => 3
Searches the string for the regular expression specified in
$pattern returning true if found or false otherwise.
[% item = String.new('foo bar baz wiz waz woz') %] [% item.search('wiz') ? 'WIZZY! :-)' : 'not wizzy :-(' %]
Splits the string based on the delimiter $pattern and
optional $limit. Delegates to Perl's internal
split() so the parameters are exactly the same.
[% FOREACH item.split %] ... [% END %] [% FOREACH item.split('baz|waz') %] ... [% END %]
These methods modify the internal value of the string. For example:
[% USE str=String('foobar') %] [% str.append('.php') %] # str => 'foobar.php'
The value of str is now 'foobar.php'. If you
don't want to modify the string then simply take a copy first.
[% str.copy.append('.php') %]
These methods all return a reference to the String object
itself. This has two important benefits. The first is that when used as
above, the String object 'str' returned by the
append() method will be stringified with a call to its
text() method. This will return the newly modified string
content. In other words, a directive like:
[% str.append('.php') %]
will update the string and also print the new value. If you just want to
update the string but not print the new value then use CALL.
[% CALL str.append('.php') %]
The other benefit of these methods returning a reference to the
String is that you can chain as many different method calls
together as you like. For example:
[% String.append('.php').trim.format(href) %]
Here are the methods:
Appends all arguments to the end of the string. The append()
method is provided as an alias for push().
[% msg.push('foo', 'bar') %] [% msg.append('foo', 'bar') %]
Removes the suffix passed as an argument from the end of the String.
[% USE String 'foo bar' %] [% String.pop(' bar') %] # => 'foo'
Prepends all arguments to the beginning of the string. The
prepend() method is provided as an alias for
unshift().
[% msg.unshift('foo ', 'bar ') %] [% msg.prepend('foo ', 'bar ') %]
Removes the prefix passed as an argument from the start of the String.
[% USE String 'foo bar' %] [% String.shift('foo ') %] # => 'bar'
If the length of the string is less than $pad then the
string is left formatted and padded with spaces to $pad
length.
[% msg.left(20) %]
Apply a format in the style of sprintf() to the string.
[% USE String("world") %] [% String.format("Hello %s\n") %] # => "Hello World\n"
Converts the string to upper case.
[% USE String("foo") %] [% String.upper %] # => 'FOO'
Converts the string to lower case
[% USE String("FOO") %] [% String.lower %] # => 'foo'
Converts the first character of the string to upper case.
[% USE String("foo") %] [% String.capital %] # => 'Foo'
The remainder of the string is left untouched. To force the string to be all lower case with only the first letter capitalised, you can do something like this:
[% USE String("FOO") %] [% String.lower.capital %] # => 'Foo'
Removes the last character from the string.
[% USE String("foop") %] [% String.chop %] # => 'foo'
Removes the trailing newline from the string.
[% USE String("foo\n") %] [% String.chomp %] # => 'foo'
Removes all leading and trailing whitespace from the string
[% USE String(" foo \n\n ") %] [% String.trim %] # => 'foo'
Removes all leading and trailing whitespace and collapses any sequences of multiple whitespace to a single space.
[% USE String(" \n\r \t foo \n \n bar \n") %] [% String.collapse %] # => "foo bar"
Truncates the string to $length characters.
[% USE String('long string') %] [% String.truncate(4) %] # => 'long'
If $suffix is specified then it will be appended to the
truncated string. In this case, the string will be further shortened by
the length of the suffix to ensure that the newly constructed string
complete with suffix is exactly $length characters long.
[% USE msg = String('Hello World') %] [% msg.truncate(8, '...') %] # => 'Hello...'
Replaces all occurences of $search in the string with
$replace.
[% USE String('foo bar foo baz') %] [% String.replace('foo', 'wiz') %] # => 'wiz bar wiz baz'
Remove all occurences of $search in the string.
[% USE String('foo bar foo baz') %] [% String.remove('foo ') %] # => 'bar baz'
Repeats the string $count times.
[% USE String('foo ') %] [% String.repeat(3) %] # => 'foo foo foo '
Andy Wardley <abw@wardley.org> https://wardley.org/
Copyright (C) 1996-2007 Andy Wardley. All Rights Reserved.
This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself.