SYNOPSIS

     use Module::XSOrPP qw(
         is_xs is_pp xs_or_pp
     );
    
     say "Class::XSAccessor is an XS module" if is_xs("Class/XSAccessor.pm");
     say "JSON::PP is a pure-Perl module" if is_pp("JSON::PP");
     say "Params::Util is an XS module with PP fallback" if xs_or_pp("Class/XSAccessor.pm") =~ /^(xs|xs_or_pp)$/;

DESCRIPTION

FUNCTIONS

 xs_or_pp($mod, \%opts) => str

    Return either "xs", "pp", or "xs_or_pp" (XS with a PP fallback). Return
    undef if can't determine which. $mod value can be in the form of
    Package/SubPkg.pm or Package::SubPkg. The following ways are tried, in
    order:

      * Predetermined list

      Some CPAN modules are XS with a PP fallback. This module maintains
      the list.

      * Looking at the .packlist

      If a .{bs,so,dll} file is listed in the .packlist, then it is assumed
      to be an XS module. This method will fail if there is no .packlist
      available (e.g. core or uninstalled or when the package management
      strips the packlist), or if a dist contains both pure-Perl and XS.

      * Looking at the source file for usage of XSLoader or DynaLoader

      If the module source code has something like use XSLoader; or <use
      DynaLoader;> then it is assumed to be an XS module. This is currently
      implemented using a simple regex, so it is somewhat brittle.

      * Guessing from the name

      If the module has "XS" in its name then it's assumed to be an XS
      module. If the module has "PP" in its name, it's assumed to be a
      pure-Perl module.

      Known false positives will be prevented in the future.

    Other methods will be added in the future (e.g. a database like in
    Module::CoreList, consulting MetaCPAN, etc).

    Options:

      * warn => BOOL (default: 0)

      If set to true, will warn to STDERR if fail to determine.

      * debug => BOOL (default: 0)

      If set to true will print debugging message to STDERR.

 is_xs($mod, \%opts) => BOOL

    Return true if module $mod is an XS module, false if a pure Perl
    module, or undef if can't determine either. See xs_or_pp for more
    details.

 is_pp($mod, \%opts) => BOOL

    Return true if module $mod is a pure Perl module or XS module with a PP
    fallback. See is_xs for more details. See xs_or_pp for more details.