2014-05-14 12:27 GMT+02:00 askoh <[email protected]>:

> There is a trend of making languages to run on Java Virtual Machine. But it
> still cannot run Smalltalk like Smalltalk on Smalltalk VM. Is it a possible
> goal?
>

Always the same dream...

To have Smalltalk running on the JVM, the main issues is that you do not
have a stack reification as contexts and you do not have become: in java.
These two features are used to keep the system live: the fancy debugger,
editing classes and migrating their instances at runtime.

There's a few other details such as having the literal array per method or
per class, the second implementation, per class, for java, makes it hard to
add a method to a class at runtime. Another detail is that not all
smalltalk can bootstrap from sources (for example it is the same heap that
we have used and edited in Pharo for the last 3 decades, the unique
instance of True may even have been instantiated by Dan Ingalls in 1980 and
we are still using it).

So basically it is either you have smalltalk running on the jvm wihtout the
live smalltalk abilities, or you have a full smalltalk but it is slow.

>
> How about running Java on the StVM so that Java can have the live
> environment and debugging capabilities like in full blown Smalltalk? How
> about doing the same for Python, Ruby, Lisp, ObjC, C#, etc?
>

This is somehow done in Smalltalk/X and in Visual Age. I think they both
support the Java 1.5 byte code. Now this is a huge pain because you have to
implement the java byte code verifier and all these boring stuff.

The OpenQuack image, a fork of squeak used by the company 3DICC, has a
plugin to run python on the smalltalk VM.

Then it depends on your use cases, but usually people prefers to do
bindings (like in Pharo you can bind C libraries, including the python/ruby
interpreter) instead of adding a full backend for another language, because
then you need to maintain the other language and we have very few people
working on smalltalk VMs that can maintain that nowadays.


> Thanks in advanced for all you thoughts.
>
> Aik-Siong Koh
>
>
>
> --
> View this message in context:
> http://forum.world.st/Smalltalk-Virtual-Machine-StVM-tp4758961.html
> Sent from the Pharo Smalltalk Developers mailing list archive at
> Nabble.com.
>
>

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