| Name : perl-Data-Flow
| |
| Version : 1.02
| Vendor : obs://build_opensuse_org/devel:languages:perl
|
| Release : lp155.1.1
| Date : 2023-07-20 17:54:42
|
| Group : Development/Libraries/Perl
| Source RPM : perl-Data-Flow-1.02-lp155.1.1.src.rpm
|
| Size : 0.01 MB
| |
| Packager : https://www_suse_com/
| |
| Summary : Perl extension for simple-minded recipe-controlled build of data
|
Description :
The module Data::Flow provides its services via objects. The objects may be
obtained by the usual
$request = new Data::Flow $recipes;
paradigm. The argument $recipes is a hash reference, which provides the
rules for request processing. The objects support three methods, set(),
get(), aget(), and already_set(). The first one is used to provide input
data for processing, the second one to obtain the output. The third one to
obtain a reference to an array with results of repeated get(), and the last
one to query whether a field is already known.
The unit of requested information is a _field_. The method set() takes a
pair \'field => value\', the methods get() and already_set() take one
argument: the \'field\', and the method aget() takes multiple fields.
Every object is created without any fields filled, but it knows how to
_construct_ fields basing on other fields or some global into. This
knowledge is provided in the argument $recipe of the new() function. This
is a reference to a hash, keyed by _fields_. The values of this hash are
hash references themselves, which describe how to acquire the _field_ which
is the corresponding key of the initial hash.
The internal hashes may have the following keys:
* \'default\'
describes the default value for the key, if none is provided by set(). The
value becomes the value of the field of the object. No additional
processing is performed. Example:
default => $Config{installdir}
* \'prerequisites\'
gives the fields which are needed for the construction of the given field.
The corresponding value is an array references. The array contains the
_required_ fields.
If \'defaults\' did not satisfy the request for a field, but
\'$recipe->{field}{prerequisites}\' exists, the _required_ fields are build
before any further processing is done. Example:
prerequisites => [ qw(prefix arch) ]
* \'process\'
contains the rule to build the field. The value is a reference to a
subroutine taking 2 arguments: the reference to a hash with all the fields
which have been set, and the name of the required field. It is up to the
subroutine to actually fill the corresponding field of the hash, an error
condition is raised if it did not. Example:
process => sub { my $data = shift;
$data->{time} = localtime(time) } }
* \'oo_process\'
contains the rule to build the field. The value is a reference to a
subroutine taking 2 arguments: the object $request, and the name of the
required field. It is up to the subroutine to actually fill the
corresponding field of $request, an error condition is raised if it did
not. Example:
oo_process => sub { my $data = shift;
$data->set( time => localtime(time) ) }
* \'output\'
the corresponing value has the same meaning as for \'process\', but the
return value of the subroutine is used as the value of the _field_.
Example:
output => sub { localtime(time) }
* \'oo_output\'
the corresponing value has the same meaning as for \'process\', but the
return value of the method is used as the value of the _field_. Example:
output => sub { my $self = shift; $self->get(\'r\') . localtime(time) }
* \'filter\'
contains the rule to build the field basing on other fields. The value is a
reference to an array. The first element of the array is a reference to a
subroutine, the rest contains names of the fields. When the subroutine is
called, the arguments are the values of _fields_ of the object $request
which appear in the array (in the same order). The return value of the
subroutine is used as the value of the _field_. Example:
filter => [ sub { shift + shift },
\'first_half\', \'second_half\' ]
Note that the mentioned field will be automatically marked as
prerequisites.
* \'self_filter\'
is similar to \'filter\', but an extra argument, the object itself, is put in
front of the list of arguments. Example:
self_filter => [ sub { my ($self, $first_half = (shift, shift);
$first_half *= -$self->get(\'total\')*100
if $first_half < 0; # negative means percentage
$first_half + shift },
\'first_half\', \'second_half\' ]
* \'class_filter\'
is similar to \'filter\', but the first argument is the name of the method to
call, second one is the name of the package to use for the method
invocation. The rest contains names of field to provide as method
arguments. Example:
class_filter => [ \'new\', \'FileHandle\', \'filename\' ]
* \'method_filter\'
is similar to \'class_filter\', but the second argument is the name of the
field which is used to call the method upon. Example:
method_filter => [ \'show\', \'widget_name\', \'current_display\' ]
|
RPM found in directory: /packages/linux-pbone/ftp5.gwdg.de/pub/opensuse/repositories/devel:/languages:/perl:/CPAN-D/15.5/noarch |
