Provided by: libperinci-sub-util-perl_0.46-1_all 
NAME
Perinci::Sub::Util - Helper when writing functions
VERSION
This document describes version 0.46 of Perinci::Sub::Util (from Perl distribution
Perinci-Sub-Util), released on 2017-01-31.
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);
$SPEC{list_users} = {
v => 1.1,
args => {
search => {},
is_suspended => {},
},
};
sub list_users { ... }
# simpler/shorter than gen_modified_sub, but can be used for currying only
gen_curried_sub('list_users', {is_suspended=>1}, 'list_suspended_users');
FUNCTIONS
gen_curried_sub($base_name, $output_name, $set_args) -> 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.
• $set_args => hash
Arguments to set.
Return value: (any)
gen_modified_sub(%args) -> [status, msg, result, meta]
Generate modified metadata (and subroutine) based on another.
Often you'll want to create another sub (and its metadata) based on another, but with some
modifications, e.g. add/remove/rename some arguments, change summary, add/remove some
properties, and so on.
Instead of cloning the Rinci metadata and modify it manually yourself, this routine
provides some shortcuts.
You can specify base sub/metadata using "base_name" (string, subroutine name, either
qualified or not) or "base_code" (coderef) + "base_meta" (hash).
This function is not exported by default, but exportable.
Arguments ('*' denotes required arguments):
• add_args => hash
Arguments to add.
• base_code => code
Base subroutine code.
If you specify this, you'll also need to specify "base_meta".
Alternatively, you can specify "base_name" instead, to let this routine search the
base subroutine from existing Perl package.
• base_meta => hash
Base Rinci metadata.
• base_name => str
Subroutine name (either qualified or not).
If not qualified with package name, will be searched in the caller's package. Rinci
metadata will be searched in %SPEC package variable.
Alternatively, you can also specify "base_code" and "base_meta".
• description => str
Description for the mod subroutine.
• install_sub => bool (default: 1)
• modify_args => hash
Arguments to modify.
For each argument you can specify a coderef. The coderef will receive the argument
($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.
If not specified will use "base_code" (which will then be required).
• 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 no "output_code" is specified, the base
subroutine reference will be assigned here.
Note that this argument is optional.
• 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.
Returns an enveloped result (an array).
First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller
error, 5xx function error). Second element (msg) is a string containing error message, or
'OK' if status is 200. Third element (result) is optional, the actual result. Fourth
element (meta) is called result metadata and is optional, a hash that contains extra
information.
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/sharyanto/perl-Perinci-Sub-Util>.
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.
SEE ALSO
Perinci
AUTHOR
perlancar <perlancar@cpan.org>
COPYRIGHT AND LICENSE
This software is copyright (c) 2017 by 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.