Perl 6 string can be converted to Perl 5 strings.

examples/perl5.pl

@@ -11,16 +11,15 @@
 package Foo;
 sub baz {
     my ($self,$arg) = @_;
-    my $who = $$arg;
-    print "Just another $who\n";
+    print "Just another $arg\n";
     return 44;
 }
 sub new {
     bless {},"Foo";
 }
 PERL5
 my $foo = eval(:lang<perl5>,'Foo->new');
-say $foo.baz(eval(:lang<perl5>,'\"Perl hacker"'));
+say $foo.baz("Perl hacker");
 say eval(:lang<perl5>,"125");
 say eval(:lang<perl5>,"13.5");
 say eval(:lang<perl5>,"'Hello there'");

lib/Perl5Interpreter.cs

@@ -30,6 +30,9 @@ public class Perl5Interpreter : IForeignInterpreter {
     [DllImport("obj/p5embed.so", EntryPoint="p5embed_SvPOKp")]
     public static extern int SvPOKp(IntPtr sv);
 
+    [DllImport("obj/p5embed.so", EntryPoint="p5embed_newSVpvn")]
+    public static extern IntPtr newSVpvn(string s,int length);
+
     public static Variable SVToVariable(IntPtr sv) {
         if (SvIOKp(sv) != 0) {
             return Builtins.MakeInt(SvIV(sv));
@@ -81,6 +84,9 @@ int argument_n
             P6any obj = var.Fetch();
             if (obj is SVany) {
                 return ((SVany)obj).sv;
+            } else if (obj.Does(Kernel.StrMO)) {
+                string s = Kernel.UnboxAny<string>(obj);
+                return Perl5Interpreter.newSVpvn(s,s.Length);
             } else {
                 throw new NieczaException("can't convert argument to p5 type");
             }

lib/p5embed.c

@@ -89,3 +89,6 @@ double p5embed_SvNV(SV* sv) {
 char* p5embed_SvPV_nolen(SV* sv) {
     return SvPV_nolen(sv);
 }
+SV* p5embed_newSVpvn(char* str,int len) {
+    return newSVpvn(str,len);
+}