[CONF] Apache Qpid > Language support for unambiguous text string and byte array types

[Justin Ross (Confluence)]

Language support for unambiguous text string and byte array types Page edited by Justin Ross Comment: Added C# Changes (1) || Language || Overloaded string/bytes type || Unambiguous array-of-bytes type || Unambiguous textual-string type || | C++ 11 | std::string | std::vector<byte> | -- | | C# | -- | byte[] | string | | Java | -- | byte[] | String | | Perl 5 | SCALAR | -- | -- | ... Full Content Language Overloaded string/bytes type Unambiguous array-of-bytes type Unambiguous textual-string type C++ 11 std::string std::vector<byte> – C# – byte[] string Java – byte[] String Perl 5 SCALAR – – PHP 5 string – – Python <= 2.5 str – unicode Python >= 2.6 str bytearray (4) unicode Python 3 – bytes, bytearray str Ruby 1.8 String – – (5) Ruby 1.9 – – String C++ 11 Since we use a box type, Variant, in C++, any difficulty interpreting strings is easily handled by qualifying the value container. It doesn't seem like too much of a stretch to me to also take this approach with bindings for languages that don't offer disambiguated types. C++ 11 doesn't seem to have a dedicated type for unicode. It has wide characters (not the same thing), and it has literal syntax for unicode strings. These resolve, however, to arrays of char, char16_t, or char32_t, so there's no type signal we can easily use to figure out the developer's intention. Perl 5 I know too little about perl to say what's going on here. Scalar::Util reftype seems to offer a way to get more type info. Perl has an array type, but its use for byte arrays doesn't appear to be recommended. [jross@localhost ~]$ perl -e 'use Scalar::Util qw(reftype); my $foo = "hello"; print reftype(\$foo) . "\n"' SCALAR [jross@localhost ~]$ perl -e 'use Scalar::Util qw(reftype); my $foo = "hello"; print reftype([]) . "\n"' ARRAY PHP 5 PHP 5 has an array type for bytes, but it's really a map with integer keys, which I would consider too inefficient for this application. http://www.php.net/manual/en/language.types.string.php http://www.php.net/manual/en/language.types.array.php Python 2 Python 2's 'bytes' type is simply an alias for str, so we can't use it to disambiguate. Python >= 2.6 does, however, have bytearray, which I think would serve well enough. Ruby 1.8 Ruby <= 1.8 doesn't have explicit string encodings, and I can't tell what the default is. Ruby >= 1.9 Ruby >= 1.9 seems to offer everything we need. Er, I'm wrong, it doesn't. It has strings with encodings; it doesn't have an explicit binary data type that is easily distinguished from text. One could use an Array of ints, but that's perhaps less efficient than we need. http://ruby-doc.org/core-2.0/String.html http://ruby-doc.org/core-2.0/Array.html irb(main):003:0> x = [1, 2, 3, 255] => [1, 2, 3, 255] irb(main):004:0> x.class => Array irb(main):016:0> x = "holla" => "holla" irb(main):017:0> x.class => String irb(main):018:0> x.encoding => #<Encoding:UTF-8> Stop watching space | Change email notification preferences View Online | View Changes | Add Comment --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@qpid.apache.org For additional commands, e-mail: commits-h...@qpid.apache.org