Provided by: libdata-types-perl_0.09-2_all 
NAME
Data::Types - Validate and convert data types.
SYNOPSIS
use Data::Types qw(:all);
my $whole = 4.5;
$whole = to_whole($whole) unless is_whole($whole);
my $int = 1.2;
$int = to_int($int) unless is_int($int);
my $decimal = '1.2foo';
$decimal = to_decimal($decimal) unless is_decimal($decimal);
my $real = '1.2foo';
$real = to_real($real) unless is_real($real);
my $float = '1.2foo';
$float = to_float($float) unless is_float($float);
my $string = [];
$string = to_string($string) unless is_string($string);
DESCRIPTION
This module exports a number of functions that are useful for validating and converting
data types. It is intended for use in applications where data types are more important
than they typically are in Perl -- e.g., database applications.
EXPORT
No functions are exported by default, though each function may be exported explicitly (see
"Functions", below, for a list of functions available for export). The following export
tags are supported:
:whole
Exports is_whole() and to_whole().
:count
Exports is_count() and to_count().
:int
Exports is_int() and to_int().
:decimal
Exports is_decimal() and to_decimal().
:real
Exports is_real() and to_real().
:float
Exports is_float() and to_float().
:string
Exports is_string() and to_string().
:is Exports all validation functions: is_whole(), is_int(), is_real(), is_decimal(),
is_float(), and is_string().
:to Exports all conversion functions: to_whole(), to_int(), to_real(), to_decimal(),
to_float(), and to_string().
:all
Exports all functions.
FUNCTIONS
is_whole
my $bool = is_whole($val);
Returns true if $val is a whole number (including 0), and false if it is not. The regular
expression used to test the wholeness of $val is "/^\d+$/".
my $bool = is_whole(1); # Returns true.
$bool = is_whole(-1); # Returns false.
$bool = is_whole(0); # Returns true.
to_whole
my $whole = to_whole($val);
Converts $val to a whole number and returns it. Numbers will be rounded to the nearest
whole. If $val is a mixture of numbers and letters, to_whole() will extract the first
decimal number it finds and convert that number to a whole number.
my $whole = to_whole(10); # Returns 10.
$whole = to_whole(0); # Returns 0.
$whole = to_whole(.22); # Returns 0.
$whole = to_whole(-2); # Returns undef.
$whole = to_whole('foo3.56'); # Returns 4.
$whole = to_whole('foo'); # Returns undef.
is_count
my $bool = is_count($val);
Returns true if $val is a counting number (1, 2, 3, ...), and false if it is not. The
regular expression used to test whether $val is a counting number is "/^\d+$/".
my $bool = is_count(1); # Returns true.
$bool = is_count(-1); # Returns false.
$bool = is_count(0); # Returns false.
to_count
my $count = to_count($val);
Converts $val to a counting number and returns it. Numbers will be rounded to the nearest
counting number. Note that since 0 (zero) is not considered a counting number by this
module, it will not be returned. If $val is a mixture of numbers and letters, to_count()
will extract the first decimal number it finds and convert that number to a counting
number.
my $count = to_count(10); # Returns 10.
$count = to_count(0); # Returns undef.
$count = to_count(.22); # Returns undef (rounded down to 0).
$count = to_count(-2); # Returns undef.
$count = to_count('foo3.56'); # Returns 4.
$count = to_count('foo'); # Returns undef.
is_int
my $bool = is_int($val);
Returns true if $val is an integer, and false if it is not. Numbers may be preceded by a
plus or minus sign. The regular expression used to test for an integer in $val is
"/^[+-]?\d+$/".
my $bool = is_int(0); # Returns true.
$bool = is_int(22); # Returns true.
$bool = is_int(-22); # Returns false.
$bool = is_int(3.2); # Returns false.
to_int
my $int = to_int($val);
Converts $val to an integer. If $val is a decimal number, it will be rounded to the
nearest integer. If $val is a mixture of numbers and letters, to_int() will extract the
first decimal number it finds and convert that number to an integer.
my $int = to_int(10.5); # Returns 10.
$int = to_int(10.51); # Returns 11.
$int = to_int(-0.22); # Returns 0.
$int = to_int(-6.51); # Returns 7.
$int = to_int('foo'); # Returns undef.
is_decimal
my $bool = is_decimal($val);
Returns true if $val is a decimal number, and false if it is not. Numbers may be preceded
by a plus or minus sign. The regular expression used to test $val is
"/^[+-]?(?:\d+(?:\.\d*)?|\.\d+)$/".
my $bool = is_decimal(10) # Returns true.
$bool = is_decimal(10.8) # Returns true.
$bool = is_decimal(-33.48) # Returns true.
$bool = is_decimal((1.23e99) # Returns false.
to_decimal
my $dec = to_decimal($val);
$dec = to_decimal($val, $precision);
Converts $val to a decimal number. The optional second argument sets the precision of the
number. The default precision is 5. If $val is a mixture of numbers and letters,
to_decimal() will extract the first decimal number it finds.
my $dec = to_decimal(0); # Returns 0.00000.
$dec = to_decimal(10.5); # Returns 10.5.
$dec = to_decimal(10.500009); # Returns 10.50001.
$dec = to_decimal(10.500009, 7); # Returns 10.5000090.
$dec = to_decimal('foo10.3') # Returns 10.30000.
$dec = to_decimal('foo-4.9') # Returns -4.90000.
$dec = to_decimal('foo') # Returns undef.
is_real
my $bool = is_real($val);
Returns true if $val is a real number, and false if it is not.
Note: This function is currently equivalent to is_decimal(), since this module cannot
identify non-decimal real numbers (e.g., irrational numbers). This implementation may
change in the future.
to_real
my $real = to_real($val);
$real = to_real($val, $precision);
Converts $val to a real number.
Note: Currently, this function is the equivalent of to_decimal(), since this module cannot
identify non-decimal real numbers (e.g., irrational numbers). This implementation may
change in the future.
is_float
my $bool = is_real($val);
Returns true if $val is a float, and false if it is not. The regular expression used to
test $val is "/^([+-]?)(?=\d|\.\d)\d*(\.\d*)?([Ee]([+-]?\d+))?$/".
my $bool = is_real(30); # Returns true.
$bool = is_real(1.23e99); # Returns true.
$bool = is_real('foo'); # Returns false.
to_float
my $dec = to_float($val);
$dec = to_float($val, $precision);
Converts $val to a float. The optional second argument sets the precision of the number.
The default precision is 5. If $val is a mixture of numbers and letters, to_float() will
extract the first float it finds.
my $float = to_float(1.23); # Returns 1.23000.
$float = to_float(1.23e99); # Returns 1.23000e+99.
$float = to_float(1.23e99, 1); # Returns 1.2e+99.
$float = to_float('foo-1.23'); # Returns -1.23000.
$float = to_float('ick_1.23e99foo'); # Returns 1.23000e+99.
is_string
my $bool = is_string($val);
Returns true if $val is a string, and false if it is not. All defined non-references are
considered strings.
my $bool = is_string('foo'); # Returns true.
$bool = is_string(20001); # Returns true.
$bool = is_string([]); # Returns false.
$bool = is_string(undef); # Returns false.
to_string
my $string = to_string($val);
$string = to_string($val, $length);
Converts $val into a string. If $val is a reference, the string value of the reference
will be returned. Such a value may be a memory address, or some other value, if the
stringification operator has been overridden for the object stored in $val. If the
optional second argument $length is passed, to_string() will truncate the string to that
length. If $length is 0 (zero), it will not limit the length of the return string. If $val
is undefined, to_string() will return undef.
my $string = to_string('foo'); # Returns 'foo'.
$string = to_string([]); # Returns 'ARRAY(0x101bec14)'.
$string = to_string(undef); # Returns undef.
$string = to_string('hello', 4); # Returns 'hell'.
SUPPORT
This module is stored in an open GitHub repository <http://github.com/theory/data-types/>.
Feel free to fork and contribute!
Please file bug reports via GitHub Issues <http://github.com/theory/data-types/issues/> or
by sending mail to bug-Data-Types.cpan.org <mailto:bug-Data-Types.cpan.org>.
Patches against Class::Meta are welcome. Please send bug reports to
<bug-data-types@rt.cpan.org>.
AUTHOR
David E. Wheeler <david@justatheory.com>
SEE ALSO
perlfaq4 lists the most of the regular expressions used to identify the different numeric
types used in this module.
String::Checker also does some data type validation.
String::Scanf reimplements the C "sscanf()" function in perl, and also does data type
validation and conversion.
Regexp::Common contains many useful common regular expressions (surprise!), including some
that can be used to identify data types.
Arthur Bergman's types pragma, offers compile-time data types for Perl 5.8.0. The data
types include int, float, and string. I highly recommend using this prgrma for fast,
static data types.
COPYRIGHT AND LICENSE
Copyright (c) 2002-2011, David E. Wheeler. Some Rights Reserved.
This module is free software; you can redistribute it and/or modify it under the same
terms as Perl itself.