oracular (3) Perinci::Sub::Util.3pm.gz
NAME
Perinci::Sub::Util - Helper when writing functions
VERSION
This document describes version 0.472 of Perinci::Sub::Util (from Perl distribution Perinci-Sub-Util),
released on 2023-10-28.
SYNOPSIS
Example for err() and caller():
use Perinci::Sub::Util qw(err caller);
sub foo {
my %args = @_;
my $res;
my $caller = caller();
$res = bar(...);
return err($err, 500, "Can't foo") if $res->[0] != 200;
[200, "OK"];
}
Example for die_err() and warn_err():
use Perinci::Sub::Util qw(warn_err die_err);
warn_err(403, "Forbidden");
die_err(403, "Forbidden");
Example for gen_modified_sub():
use Perinci::Sub::Util qw(gen_modified_sub);
$SPEC{list_users} = {
v => 1.1,
args => {
search => {},
is_suspended => {},
},
};
sub list_users { ... }
gen_modified_sub(
output_name => 'list_suspended_users',
base_name => 'list_users',
remove_args => ['is_suspended'],
output_code => sub {
list_users(@_, is_suspended=>1);
},
);
Example for gen_curried_sub():
use Perinci::Sub::Util qw(gen_curried_sub);
$SPEC{list_users} = {
v => 1.1,
args => {
search => {},
is_suspended => {},
},
};
sub list_users { ... }
# simpler/shorter than gen_modified_sub, but can be used for currying only
gen_curried_sub('list_users', {is_suspended=>1}, 'list_suspended_users');
FUNCTIONS
gen_curried_sub
Usage:
gen_curried_sub($base_name, $set_args, $output_name) -> any
Generate curried subroutine (and its metadata).
This is a more convenient helper than "gen_modified_sub" if you want to create a new subroutine that has
some of its arguments preset (so they no longer need to be present in the new metadata).
For more general needs of modifying a subroutine (e.g. add some arguments, modify some arguments, etc)
use "gen_modified_sub".
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
• $base_name* => str
Subroutine name (either qualified or not).
If not qualified with package name, will be searched in the caller's package. Rinci metadata will be
searched in %SPEC package variable.
• $output_name => str
Where to install the modified sub.
Subroutine will be put in the specified name. If the name is not qualified with package name, will
use caller's package. If the name is not specified, will use the base name which must not be in the
caller's package.
• $set_args* => hash
Arguments to set.
Return value: (any)
gen_modified_sub
Usage:
gen_modified_sub(%args) -> [$status_code, $reason, $payload, \%result_meta]
Generate modified metadata (and subroutine) based on another.
Often you'll want to create another sub (and its metadata) based on another, but with some modifications,
e.g. add/remove/rename some arguments, change summary, add/remove some properties, and so on.
Instead of cloning the Rinci metadata and modify it manually yourself, this routine provides some
shortcuts.
You can specify base sub/metadata using "base_name" (string, subroutine name, either qualified or not) or
"base_code" (coderef) + "base_meta" (hash).
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
• add_args => hash
Arguments to add.
• base_code => code
Base subroutine code.
If you specify this, you'll also need to specify "base_meta".
Alternatively, you can specify "base_name" instead, to let this routine search the base subroutine
from existing Perl package.
• base_meta => hash
Base Rinci metadata.
• base_name => str
Subroutine name (either qualified or not).
If not qualified with package name, will be searched in the caller's package. Rinci metadata will be
searched in %SPEC package variable.
Alternatively, you can also specify "base_code" and "base_meta".
Either "base_name" or "base_code" + "base_meta" are required.
• description => str
Description for the mod subroutine.
• die => bool
Die upon failure.
• install_sub => bool (default: 1)
(No description)
• modify_args => hash
Arguments to modify.
For each argument you can specify a coderef. The coderef will receive the argument ($arg_spec) and is
expected to modify the argument specification.
• modify_meta => code
Specify code to modify metadata.
Code will be called with arguments ($meta) where $meta is the cloned Rinci metadata.
• output_code => code
Code for the modified sub.
Alternatively you can use "wrap_code". If both are not specified, will use "base_code" (which will
then be required) as the modified subroutine's code.
• output_name => str
Where to install the modified sub.
Output subroutine will be put in the specified name. If the name is not qualified with package name,
will use caller's package. If the name is not specified, the base name will be used and must not be
from the caller's package.
Note that this argument is optional.
To prevent installing subroutine, set "install_sub" to false.
• remove_args => array
List of arguments to remove.
• rename_args => hash
Arguments to rename.
• replace_args => hash
Arguments to add.
• summary => str
Summary for the mod subroutine.
• wrap_code => code
Wrapper to generate the modified sub.
The modified sub will become:
sub { wrap_code->(base_code, @_) }
Alternatively you can use "output_code". If both are not specified, will use "base_code" (which will
then be required) as the modified subroutine's code.
Returns an enveloped result (an array).
First element ($status_code) is an integer containing HTTP-like status code (200 means OK, 4xx caller
error, 5xx function error). Second element ($reason) is a string containing error message, or something
like "OK" if status is 200. Third element ($payload) is the actual result, but usually not present when
enveloped result is an error response ($status_code is not 2xx). Fourth element (%result_meta) is called
result metadata and is optional, a hash that contains extra information, much like how HTTP response
headers provide additional metadata.
Return value: (hash)
caller([ $n ])
Just like Perl's builtin caller(), except that this one will ignore wrapper code in the call stack. You
should use this if your code is potentially wrapped. See Perinci::Sub::Wrapper for more details.
err(...) => ARRAY
Experimental.
Generate an enveloped error response (see Rinci::function). Can accept arguments in an unordered fashion,
by utilizing the fact that status codes are always integers, messages are strings, result metadata are
hashes, and previous error responses are arrays. Error responses also seldom contain actual result.
Status code defaults to 500, status message will default to "FUNC failed". This function will also fill
the information in the "logs" result metadata.
Examples:
err(); # => [500, "FUNC failed", undef, {...}];
err(404); # => [404, "FUNC failed", undef, {...}];
err(404, "Not found"); # => [404, "Not found", ...]
err("Not found", 404); # => [404, "Not found", ...]; # order doesn't matter
err([404, "Prev error"]); # => [500, "FUNC failed", undef,
# {logs=>[...], prev=>[404, "Prev error"]}]
Will put "stack_trace" in logs only if "Carp::Always" module is loaded.
warn_err(...)
This is a shortcut for:
$res = err(...);
warn "ERROR $res->[0]: $res->[1]";
die_err(...)
This is a shortcut for:
$res = err(...);
die "ERROR $res->[0]: $res->[1]";
FAQ
What if I want to put result ($res->[2]) into my result with err()?
You can do something like this:
my $err = err(...) if ERROR_CONDITION;
$err->[2] = SOME_RESULT;
return $err;
HOMEPAGE
Please visit the project's homepage at <https://metacpan.org/release/Perinci-Sub-Util>.
SOURCE
Source repository is at <https://github.com/perlancar/perl-Perinci-Sub-Util>.
SEE ALSO
Perinci
AUTHOR
perlancar <perlancar@cpan.org>
CONTRIBUTOR
Steven Haryanto <stevenharyanto@gmail.com>
CONTRIBUTING
To contribute, you can send patches by email/via RT, or send pull requests on GitHub.
Most of the time, you don't need to build the distribution yourself. You can simply modify the code, then
test via:
% prove -l
If you want to build the distribution (e.g. to try to install it locally on your system), you can install
Dist::Zilla, Dist::Zilla::PluginBundle::Author::PERLANCAR, Pod::Weaver::PluginBundle::Author::PERLANCAR,
and sometimes one or two other Dist::Zilla- and/or Pod::Weaver plugins. Any additional steps required
beyond that are considered a bug and can be reported to me.
COPYRIGHT AND LICENSE
This software is copyright (c) 2023, 2020, 2017, 2016, 2015, 2014 by perlancar <perlancar@cpan.org>. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.
BUGS
Please report any bugs or feature requests on the bugtracker website
<https://rt.cpan.org/Public/Dist/Display.html?Name=Perinci-Sub-Util>
When submitting a bug or request, please include a test-file or a patch to an existing test-file that
illustrates the bug or desired feature.