Provided by: libperinci-sub-util-perl_0.46-1_all bug

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.