JRuby and Truffle Interop

JRuby supports standard Truffle interop messages. This document explains what it does when it receives them, how to get it to explicitly send them, how to get it to send them using more idiomatic Ruby, and how what messages it sends for normal Ruby operations on foreign objects.

How JRuby responds to messages

IS_EXECUTABLE

Returns true only for instances of Method and Proc.

EXECUTE

Calls either a Method or Proc, passing the arguments as you'd expect. Doesn't pass a block.

INVOKE

Todo

HAS_SIZE

Returns true only for instances of Array, Hash and String.

GET_SIZE

Call size on the object.

IS_BOXED

Returns true only for instances of String with a length of 1, which allows them to be unboxed as a character.

UNBOX

For a String, returns the first character. Unboxing empty strings is not supported and will cause an UnsupportedMessageException. For all other objects returns the object.

IS_NULL

Returns true only for the nil object.

READ

Todo

WRITE

Todo

How to explicitly send messages from JRuby

IS_EXECUTABLE

Todo

EXECUTE

Todo

INVOKE

Todo

HAS_SIZE

Todo

GET_SIZE

Todo

IS_BOXED

Todo

UNBOX

Todo

IS_NULL

Todo

READ

Todo

WRITE

Todo

How to send messages using idiomatic Ruby

IS_EXECUTABLE

Todo

EXECUTE

Todo

INVOKE

Todo

HAS_SIZE

Todo

GET_SIZE

Todo

IS_BOXED

Todo

UNBOX

Todo

IS_NULL

Todo

READ

Todo

WRITE

Todo

What messages are sent for Ruby syntax on foreign objects

Todo