NAME Perinci::Sub::Util - Helper when writing functions VERSION This document describes version 0.39 of Perinci::Sub::Util (from Perl distribution Perinci-Sub-Util), released on 2014-09-25. 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 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 die_err() and warn_err(): use Perinci::Sub::Util qw(warn_err die_err); warn_err(403, "Forbidden"); die_err(403, "Forbidden"); FUNCTIONS 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]: $res->[1]"; gen_modified_sub(%args) -> [status, msg, result, meta] Generate modified metadata (and subroutine) based on another. Often you'll want to create another sub (and its metadata) based on another, but with some modifications, e.g. add/remove/rename some arguments, change summary, add/remove some properties, and so on. Instead of cloning the Rinci metadata and modify it manually yourself, this routine provides some shortcuts. You can specify base sub/metadata using "base_name" (string, subroutine name, either qualified or not) or "base_code" (coderef) + "base_meta" (hash). Arguments ('*' denotes required arguments): * add_args => *hash* Arguments to add. * base_code => *code* Base subroutine code. If you specify this, you'll also need to specify "base_meta". Alternatively, you can specify "base_name" instead, to let this routine search the base subroutine from existing Perl package. * base_meta => *hash* Base Rinci metadata. * base_name => *str* Subroutine name (either qualified or not). If not qualified with package name, will be searched in the caller's package. Rinci metadata will be searched in %SPEC package variable. Alternatively, you can also specify "base_code" and "base_meta". * description => *str* Description for the mod subroutine. * install_sub => *bool* (default: 1) * modify_args => *hash* Arguments to modify. For each argument you can specify a coderef. The coderef will receive the argument ($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 $meta is the cloned Rinci metadata. * output_name => *str* Where to install the modified sub. Subroutine will be put in the specified name. If the name is not qualified with package name, will use caller's package. If no "output_code" is specified, the base subroutine reference will be assigned here. Note that this argument is optional. * remove_args => *array* List of arguments to remove. * rename_args => *hash* Arguments to rename. * replace_args => *hash* Arguments to add. * summary => *str* Summary for the mod subroutine. Return value: Returns an enveloped result (an array). First element (status) is an integer containing HTTP status code (200 means OK, 4xx caller error, 5xx function error). Second element (msg) is a string containing error message, or 'OK' if status is 200. Third element (result) is optional, the actual result. Fourth element (meta) is called result metadata and is optional, a hash that contains extra information. (hash) FAQ What if I want to put result ($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; TODO Perinci::Sub::Wrapper will generate wrapper that modifies caller() for the wrapped subroutine (like in Hook::LexWrap), so this module's caller() will not be needed in the future. SEE ALSO Perinci HOMEPAGE Please visit the project's homepage at . SOURCE Source repository is at . BUGS Please report any bugs or feature requests on the bugtracker website 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. AUTHOR perlancar COPYRIGHT AND LICENSE This software is copyright (c) 2014 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.