🚀 go-pugleaf

Matthew Dillon writes:

>    I should mention that a strong run-time system cannot be optimized
>    easily (or at all) whereas a strong compile-time and load-time system
>    can both be optimized AND handle interface portability concerns without
>    any run-time system getting in the way, but that generally entails
>    building part of the compiler into every machine to handle
>    'installation' (integration) of an application.  C++ has yet to reach
>    this capability and may never do so as it insists, as most languages
>    do, on sticking to a strict compile time paradigm.

In fact I would argue that the interface run-time should be
completely language-independent as well as very fast. As Matthew
points out, a compile and load oriented system such as fast
RPC interfaces is advantageous. What this means is that in
local bindings between code and an externally-supplied module
(or "software IC"), the performance hit can be as small as
a single register or memory indirection -- less if you are
willing to do relocation on load (just depends where you want
to spend your CPU cycles and when). When you go cross-machine,
you convert to a messaging system using standard RPC techniques.

Objective-C and the NeXT run-time always use messaging, and
perform language-specific optimizations for in-process
invocation. The messaging system also brings synchronization
issues in multi-threaded environments since the message 
encapsulates synchronization semantics whereas compiler
invocations do not. The developer that therefore writes
a software component must use messaging, think about
thread safety in the client run-time, and therefore
worry about distribution transparency (i.e. where the
component code runs).

Issues such as how to write a reusable and distributable
component should really not be addressed in a language.
They should be addressed as an infrastructure for an object
system that is language independent. Then you can worry
about language bindings and new languages that are semantically
identical to the object system's model. It is hard to imagine,
esp. given the religion on languages, that any one language
will meet all needs.

--
Edward Jung, Software Architect     edwardj@microsoft.com
Advanced Systems, Microsoft Corp.