File Coverage

blib/lib/Perinci/Sub/Util.pm

Criterion	Covered	Total	%
statement	141	175	80.5
branch	51	82	62.2
condition	20	40	50.0
subroutine	15	18	83.3
pod	6	6	100.0
total	233	321	72.5

package Perinci::Sub::Util;

use 5.010001;
use strict;
use warnings;
use Log::ger;

use Exporter qw(import);

our $AUTHORITY = 'cpan:PERLANCAR'; # AUTHORITY
our $DATE = '2023-07-02'; # DATE
our $DIST = 'Perinci-Sub-Util'; # DIST
our $VERSION = '0.471'; # VERSION

our @EXPORT_OK = qw(
                       err
                       caller
                       warn_err
                       die_err
                       gen_modified_sub
                       gen_curried_sub
               );

our %SPEC;

$SPEC{':package'} = {
    v => 1.1,
    summary => 'Helper when writing functions',
};

our $STACK_TRACE;
our @_c; # to store temporary celler() result
our $_i; # temporary variable
sub err {
    require Scalar::Util;

    # get information about caller
    my @caller = CORE::caller(1);
    if (!@caller) {
        # probably called from command-line (-e)
        @caller = ("main", "-e", 1, "program");
    }

    my ($status, $msg, $meta, $prev);

    for (@_) {
        my $ref = ref($_);
        if ($ref eq 'ARRAY') { $prev = $_ }
        elsif ($ref eq 'HASH') { $meta = $_ }
        elsif (!$ref) {
            if (Scalar::Util::looks_like_number($_)) {
                $status = $_;
            } else {
                $msg = $_;
            }
        }
    }

    $status //= 500;
    $msg  //= "$caller[3] failed";
    $meta //= {};
    $meta->{prev} //= $prev if $prev;

    # put information on who produced this error and where/when
    if (!$meta->{logs}) {

        # should we produce a stack trace?
        my $stack_trace;
        {
            no warnings;
            # we use Carp::Always as a sign that user wants stack traces
            last unless $STACK_TRACE // $INC{"Carp/Always.pm"};
            # stack trace is already there in previous result's log
            last if $prev && ref($prev->[3]) eq 'HASH' &&
                ref($prev->[3]{logs}) eq 'ARRAY' &&
                    ref($prev->[3]{logs}[0]) eq 'HASH' &&
                        $prev->[3]{logs}[0]{stack_trace};
            $stack_trace = [];
            $_i = 1;
            while (1) {
                {
                    package DB;
                    @_c = CORE::caller($_i);
                    if (@_c) {
                        $_c[4] = [@DB::args];
                    }
                }
                last unless @_c;
                push @$stack_trace, [@_c];
                $_i++;
            }
        }
        push @{ $meta->{logs} }, {
            type    => 'create',
            time    => time(),
            package => $caller[0],
            file    => $caller[1],
            line    => $caller[2],
            func    => $caller[3],
            ( stack_trace => $stack_trace ) x !!$stack_trace,
        };
    }

    #die;
    [$status, $msg, undef, $meta];
}

sub warn_err {
    require Carp;

    my $res = err(@_);
    Carp::carp("ERROR $res->[0]: $res->[1]");
}

sub die_err {
    require Carp;

    my $res = err(@_);
    Carp::croak("ERROR $res->[0]: $res->[1]");
}

sub caller {
    my $n0 = shift;
    my $n  = $n0 // 0;

    my $pkg = $Perinci::Sub::Wrapper::default_wrapped_package //
        'Perinci::Sub::Wrapped';

    my @r;
    my $i =  0;
    my $j = -1;
    while ($i <= $n+1) { # +1 for this sub itself
        $j++;
        @r = CORE::caller($j);
        last unless @r;
        if ($r[0] eq $pkg && $r[1] =~ /^\(eval /) {
            next;
        }
        $i++;
    }

    return unless @r;
    return defined($n0) ? @r : $r[0];
}

$SPEC{gen_modified_sub} = {
    v => 1.1,
    summary => 'Generate modified metadata (and subroutine) based on another',
    description => <<'_',

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).

_
    args => {
        base_name => {
            summary => 'Subroutine name (either qualified or not)',
            schema => 'str*',
            description => <<'_',

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.

_
        },
        base_code => {
            summary => 'Base subroutine code',
            schema  => 'code*',
            description => <<'_',

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 => {
            summary => 'Base Rinci metadata',
            schema  => 'hash*', # XXX defhash/rifunc
        },
        output_name => {
            summary => 'Where to install the modified sub',
            schema  => 'str*',
            description => <<'_',

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.
_
        },
        output_code => {
            summary => 'Code for the modified sub',
            schema  => 'code*',
            description => <<'_',

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.

_
        },
        wrap_code => {
            summary => 'Wrapper to generate the modified sub',
            schema  => 'code*',
            description => <<'_',

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.

_
        },
        summary => {
            summary => 'Summary for the mod subroutine',
            schema  => 'str*',
        },
        description => {
            summary => 'Description for the mod subroutine',
            schema  => 'str*',
        },
        remove_args => {
            summary => 'List of arguments to remove',
            schema  => 'array*',
        },
        add_args => {
            summary => 'Arguments to add',
            schema  => 'hash*',
        },
        replace_args => {
            summary => 'Arguments to add',
            schema  => 'hash*',
        },
        rename_args => {
            summary => 'Arguments to rename',
            schema  => 'hash*',
        },
        modify_args => {
            summary => 'Arguments to modify',
            description => <<'_',

For each argument you can specify a coderef. The coderef will receive the
argument ($arg_spec) and is expected to modify the argument specification.

_
            schema  => 'hash*',
        },
        modify_meta => {
            summary => 'Specify code to modify metadata',
            schema  => 'code*',
            description => <<'_',

Code will be called with arguments ($meta) where $meta is the cloned Rinci
metadata.

_
        },
        install_sub => {
            schema  => 'bool',
            default => 1,
        },
    },
    args_rels => {
        req_one => [qw/base_name base_code/],
        choose_all => [qw/base_code base_meta/],
    },
    result => {
        schema => ['hash*' => {
            keys => {
                code => ['code*'],
                meta => ['hash*'], # XXX defhash/risub
            },
        }],
    },
};
sub gen_modified_sub {
    require Function::Fallback::CoreOrPP;

    my %args = @_;

    # get base code/meta
    my $caller_pkg = CORE::caller();
    my ($base_code, $base_meta);
    my ($base_pkg, $base_leaf);
    if ($args{base_name}) {
        if ($args{base_name} =~ /(.+)::(.+)/) {
            ($base_pkg, $base_leaf) = ($1, $2);
        } else {
            $base_pkg  = $caller_pkg;
            $base_leaf = $args{base_name};
        }
        {
            no strict 'refs'; ## no critic: TestingAndDebugging::ProhibitNoStrict
            $base_code = \&{"$base_pkg\::$base_leaf"};
            $base_meta = ${"$base_pkg\::SPEC"}{$base_leaf};
        }
        die "Can't find Rinci metadata for $base_pkg\::$base_leaf" unless $base_meta;
    } elsif ($args{base_meta}) {
        $base_meta = $args{base_meta};
        $base_code = $args{base_code}
            or die "Please specify base_code";
    } else {
        die "Please specify base_name or base_code+base_meta";
    }

    my $output_meta = Function::Fallback::CoreOrPP::clone($base_meta);
    my $output_code = ($args{wrap_code} ? sub { $args{wrap_code}->($base_code, @_) } : undef) //
        $args{output_code} // $base_code;

    # modify metadata
    for (qw/summary description/) {
        $output_meta->{$_} = $args{$_} if $args{$_};
    }
    if ($args{remove_args}) {
        delete $output_meta->{args}{$_} for @{ $args{remove_args} };
    }
    if ($args{add_args}) {
        for my $k (keys %{ $args{add_args} }) {
            my $v = $args{add_args}{$k};
            die "Can't add arg '$k' in mod sub: already exists"
                if $output_meta->{args}{$k};
            $output_meta->{args}{$k} = $v;
        }
    }
    if ($args{replace_args}) {
        for my $k (keys %{ $args{replace_args} }) {
            my $v = $args{replace_args}{$k};
            die "Can't replace arg '$k' in mod sub: doesn't exist"
                unless $output_meta->{args}{$k};
            $output_meta->{args}{$k} = $v;
        }
    }
    if ($args{rename_args}) {
        for my $old (keys %{ $args{rename_args} }) {
            my $new = $args{rename_args}{$old};
            my $as = $output_meta->{args}{$old};
            die "Can't rename arg '$old' in mod sub: doesn't exist" unless $as;
            die "Can't rename arg '$old'->'$new' in mod sub: ".
                "new name already exist" if $output_meta->{args}{$new};
            $output_meta->{args}{$new} = $as;
            delete $output_meta->{args}{$old};
        }
    }
    if ($args{modify_args}) {
        for (keys %{ $args{modify_args} }) {
            $args{modify_args}{$_}->($output_meta->{args}{$_});
        }
    }
    if ($args{modify_meta}) {
        $args{modify_meta}->($output_meta);
    }

    # install
    my ($output_pkg, $output_leaf);
    if (!defined $args{output_name}) {
        $output_pkg  = $caller_pkg;
        $output_leaf = $base_leaf;
        return [412, "Won't override $base_pkg\::$base_leaf"]
            if $base_pkg eq $output_pkg;
    } elsif ($args{output_name} =~ /(.+)::(.+)/) {
        ($output_pkg, $output_leaf) = ($1, $2);
    } else {
        $output_pkg  = $caller_pkg;
        $output_leaf = $args{output_name};
    }
    {
        no strict 'refs'; ## no critic: TestingAndDebugging::ProhibitNoStrict
        no warnings 'redefine', 'once';
        log_trace "Installing modified sub to $output_pkg\::$output_leaf ...";
        *{"$output_pkg\::$output_leaf"} = $output_code if $args{install_sub} // 1;
        ${"$output_pkg\::SPEC"}{$output_leaf} = $output_meta;
    }

    [200, "OK", {code=>$output_code, meta=>$output_meta}];
}

$SPEC{gen_curried_sub} = {
    v => 1.1,
    summary => 'Generate curried subroutine (and its metadata)',
    description => <<'_',

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`.

_
    args => {
        base_name => {
            summary => 'Subroutine name (either qualified or not)',
            schema => 'str*',
            description => <<'_',

If not qualified with package name, will be searched in the caller's package.
Rinci metadata will be searched in `%SPEC` package variable.

_
            req => 1,
            pos => 0,
        },
        set_args => {
            summary => 'Arguments to set',
            schema  => 'hash*',
            req => 1,
            pos => 1,
        },
        output_name => {
            summary => 'Where to install the modified sub',
            schema  => 'str*',
            description => <<'_',

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.

_
            pos => 2,
        },
    },
    args_as => 'array',
    result_naked => 1,
};
sub gen_curried_sub {
    my ($base_name, $set_args, $output_name) = @_;

    my $caller = CORE::caller();

    my ($base_pkg, $base_leaf);
    if ($base_name =~ /(.+)::(.+)/) {
        ($base_pkg, $base_leaf) = ($1, $2);
    } else {
        $base_pkg  = $caller;
        $base_leaf = $base_name;
    }

    my ($output_pkg, $output_leaf);
    if (!defined $output_name) {
        die "Won't override $base_pkg\::$base_leaf" if $base_pkg eq $caller;
        $output_pkg = $caller;
        $output_leaf = $base_leaf;
    } elsif ($output_name =~ /(.+)::(.+)/) {
        ($output_pkg, $output_leaf) = ($1, $2);
    } else {
        $output_pkg  = $caller;
        $output_leaf = $output_name;
    }

    my $base_sub = \&{"$base_pkg\::$base_leaf"};

    my $res = gen_modified_sub(
        base_name   => "$base_pkg\::$base_leaf",
        output_name => "$output_pkg\::$output_leaf",
        output_code => sub {
            no strict 'refs'; ## no critic: TestingAndDebugging::ProhibitNoStrict
            $base_sub->(@_, %$set_args);
        },
        remove_args => [keys %$set_args],
        install => 1,
    );

    die "Can't generate curried sub: $res->[0] - $res->[1]"
        unless $res->[0] == 200;

    1;
}

1;
# ABSTRACT: Helper when writing functions

__END__