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NAME
    Scalar::Properties - Run-time properties on scalar variables

VERSION
    version 1.100860

SYNOPSIS
      use Scalar::Properties;
      my $val = 0->true;
        if ($val && $val == 0) {
        print "yup, its true alright...\n";
      }

      my @text = (
        'hello world'->greeting(1),
        'forget it',
        'hi there'->greeting(1),
      );
      print grep { $_->is_greeting } @text;

      my $l =  'hello world'->length;

DESCRIPTION
    Scalar::Properties attempts to make Perl more object-oriented by taking
    an idea from Ruby: Everything you manipulate is an object, and the
    results of those manipulations are objects themselves.

      'hello world'->length
      (-1234)->abs
      "oh my god, it's full of properties"->index('g')

    The first example asks a string to calculate its length. The second
    example asks a number to calculate its absolute value. And the third
    example asks a string to find the index of the letter 'g'.

    Using this module you can have run-time properties on initialized scalar
    variables and literal values. The word 'properties' is used in the Perl
    6 sense: out-of-band data, little sticky notes that are attached to the
    value. While attributes (as in Perl 5's attribute pragma, and see the
    "Attribute::*" family of modules) are handled at compile-time,
    properties are handled at run-time.

    Internally properties are implemented by making their values into
    objects with overloaded operators. The actual properties are then simply
    hash entries.

    Most properties are simply notes you attach to the value, but some may
    have deeper meaning. For example, the "true" and "false" properties
    plays a role in boolean context, as the first example of the Synopsis
    shows.

    Properties can also be propagated between values. For details, see the
    EXPORTS section below. Here is an example why this might be desirable:

      pass_on('approximate');
      my $pi = 3->approximate(1);
      my $circ = 2 * $rad * $pi;

      # now $circ->approximate indicates that this value was derived
      # from approximate values

    Please don't use properties whose name start with an underscore; these
    are reserved for internal use.

    You can set and query properties like this:

    "$var->myprop(1)"
        sets the property to a true value.

    "$var->myprop(0)"
        sets the property to a false value. Note that this doesn't delete
        the property (to do so, use the "del_props" method described below).

    "$var->is_myprop", "$var->has_myprop"
        returns a true value if the property is set (i.e., defined and has a
        true value). The two alternate interfaces are provided to make
        querying attributes sound more natural. For example:

          $foo->is_approximate;
          $bar->has_history;

    Values thus made into objects also expose various utility methods. All
    of those methods (unless noted otherwise) return the result as an
    overloaded value ready to take properties and method calls itself, and
    don't modify the original value.

METHODS
  get_props
    Get a list of names of the value's properties.

  del_props(LIST)
    Deletes one or more properties from the value. This is different than
    setting the property value to zero.

  del_all_props
    Deletes all of the value's properties.

  plus(EXPR)
    Returns the value that is the sum of the value whose method has been
    called and the argument value. This method also overloads addition, so:

      $a = 7 + 2;
      $a = 7->plus(2);    # the same

  minus(EXPR)
    Returns the value that is the the value whose method has been called
    minus the argument value. This method also overloads subtraction.

  times(EXPR)
    Returns the value that is the the value whose method has been called
    times the argument value. This method also overloads multiplication.

  divide(EXPR)
    Returns the value that is the the value whose method has been called
    divided by the argument value. This method also overloads division.

  modulo(EXPR)
    Returns the value that is the the value whose method has been called
    modulo the argument value. This method also overloads the modulo
    operator.

  exp(EXPR)
    Returns the value that is the the value whose method has been called
    powered by the argument value. This method also overloads the
    exponentiation operator.

  abs
    Returns the absolute of the value.

  zero
    Returns a boolean value indicating whether the value is equal to 0.

  length
    Returns the result of the built-in "length" function applied to the
    value.

  size
    Same as "length()".

  reverse
    Returns the reverse string of the value.

  uc
    Returns the result of the built-in function "uc()" applied to the value.

  ucfirst
    Returns the result of the built-in function "ucfirst()" applied to the
    value.

  lc
    Returns the result of the built-in function "lc()" applied to the value.

  lcfirst
    Returns the result of the built-in function "lcfirst()" applied to the
    value.

  hex
    Returns the result of the built-in function "hex()" applied to the
    value.

  oct
    Returns the result of the built-in function "oct()" applied to the
    value.

  concat(EXPR)
    Returns the result of the argument expression appended to the value.

  append(EXPR)
    Same as "concat(EXPR)".

  swapcase
    Returns a version of the value with every character's case reversed,
    i.e. a lowercase character becomes uppercase and vice versa.

  split /PATTERN/, LIMIT
    Returns a list of overloaded values that is the result of splitting
    (according to the built-in "split" function) the value along the
    pattern, into a number of values up to the limit.

  numcmp(EXPR)
    Returns the (overloaded) value of the numerical three-way comparison.
    This method also overloads the "<=>" operator.

  cmp(EXPR)
    Returns the (overloaded) value of the alphabetical three-way comparison.
    This method also overloads the "cmp" operator.

  eq(EXPR)
    Return the (overloaded) boolean value of the "eq" string comparison.
    This method also overloads that operators.

  ne(EXPR)
    Return the (overloaded) boolean value of the "ne" string comparison.
    This method also overloads that operators.

  lt(EXPR)
    Return the (overloaded) boolean value of the "lt" string comparison.
    This method also overloads that operators.

  gt(EXPR)
    Return the (overloaded) boolean value of the "gt" string comparison.
    This method also overloads that operators.

  le(EXPR)
    Return the (overloaded) boolean value of the "le" string comparison.
    This method also overloads that operators.

  ge(EXPR)
    Return the (overloaded) boolean value of the "ge" string comparison.
    This method also overloads that operators.

  eqi
    Same as "eq()", but is case-insensitive.

  nei>
    Same as "ne()", but is case-insensitive.

  lti
    Same as "lt()", but is case-insensitive.

  gti
    Same as "gt()", but is case-insensitive.

  lei
    Same as "le()", but is case-insensitive.

  gei
    Same as "ge()", but is case-insensitive.

  is_true
    Returns whether the (overloaded) boolean status of the value is true.

  is_false
    Returns whether the (overloaded) boolean status of the value is false.

  create
    FIXME

  del_prop
    FIXME

  do_downto
    FIXME

  do_downto_step
    FIXME

  do_upto
    FIXME

  do_upto_step
    FIXME

  false
    FIXME

  gen_meth
    FIXME

  handle
    FIXME

  times_do
    FIXME

  true
    FIXME

  value
    FIXME

FUNCTIONS
  pass_on(LIST)
    Sets (replaces) the list of properties that are passed on. There is only
    one such list for the whole mechanism. The whole property interface is
    experimental, but this one in particular is likely to change in the
    future. This function is exported automatically.

  passed_on(STRING)
    Tests whether a property is passed on and returns a boolean value. This
    function is exported automatically.

  get_pass_on
    Returns a list of names of properties that are passed on. This function
    is exported automatically.

INSTALLATION
    See perlmodinstall for information and options on installing Perl
    modules.

BUGS AND LIMITATIONS
    No bugs have been reported.

    Please report any bugs or feature requests through the web interface at
    <http://rt.cpan.org/Public/Dist/Display.html?Name=Scalar-Properties>.

AVAILABILITY
    The latest version of this module is available from the Comprehensive
    Perl Archive Network (CPAN). Visit <http://www.perl.com/CPAN/> to find a
    CPAN site near you, or see
    <http://search.cpan.org/dist/Scalar-Properties/>.

    The development version lives at
    <http://github.com/hanekomu/Scalar-Properties/>. Instead of sending
    patches, please fork this project using the standard git and github
    infrastructure.

AUTHOR
      Marcel Gruenauer <marcel@cpan.org>

COPYRIGHT AND LICENSE
    This software is copyright (c) 2001 by Marcel Gruenauer.

    This is free software; you can redistribute it and/or modify it under
    the same terms as the Perl 5 programming language system itself.