/ 
Wasm-0.23
River stage one • 1 direct dependent • 1 total dependent
/ Wasm::Trap

NAME

Wasm::Trap - Wasm trap class

VERSION

version 0.23

SYNOPSIS

use Wasm::Trap;

my $trap = Wasm::Trap->new(
  "something went bump in the night\0",
);

DESCRIPTION

WARNING: WebAssembly and Wasmtime are a moving target and the interface for these modules is under active development. Use with caution.

This class represents a trap thrown into or out of WebAssembly. It can be thrown back to WebAssembly via die in a Perl function called from WebAssembly. It can be caught in Perl via eval around WebAssembly.

The actual implementation may be a super or subclass. As of this writing it is a simple wrapper around Wasm::Wasmtime::Trap, but relying on that is undefined behavior. In order to catch a trap from WebAssembly, use this class name like so:

use Ref::Util qw( is_blessed_ref );

local $@ = '';
eval {
  web_assembly_func();
};
if(my $error = $@)
{
  if(is_blessed_ref $error && $error->isa('Wasm::Trap'))
  {
    my $message = $error->message;
    my $exit_value = $error->exit_value;
    print "message    = $message\n";
    print "exit_value = $exit_value\n";
  }
}

To throw from Perl:

use Wasm::Trap;

sub perl_from_wasm
{
  die Wasm::Trap->new("diagnostic\0");
}

CONSTRUCTORS

new

my $trap = Wasm::Trap->new($message);

This creates a new trap object.

METHODS

message

my $message = $trap->message;

Returns the trap message as a string.

exit_status

my $status = $trap->exit_status;

If the trap was triggered by an exit call, this will return the exist status code. If it wasn't triggered by an exit call it will return undef.

SEE ALSO

Wasm

AUTHOR

Graham Ollis <plicease@cpan.org>

COPYRIGHT AND LICENSE

This software is copyright (c) 2020-2022 by Graham Ollis.

This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself.