From: Eleanor McHugh <eleanor@...>
Date: 2008-07-11T23:51:00+09:00
Subject: Re: Why Ruby interpreter is writed in c (not in c++)?

On 11 Jul 2008, at 15:23, M. Edward (Ed) Borasky wrote:
> Eleanor McHugh wrote:
>>> All system-level engines are written in C, not C++. C has been a  
>>> Standard for much longer, and has more compliant compilers. So any  
>>> engine that wants to run on the widest number of platforms must  
>>> use C. It compiles for everything from wristwatches to Mars Rovers.
>> It may well compile for them, but there are systems where even diet  
>> libc would be too heavy a runtime requirement which is why many  
>> embedded applications still use assembly language.
>
> There's also another light-weight libc -- I forget the name, but  
> there is a whole "buildroot" toolchain as well for embedded systems.  
> Then, of course, there's Forth, which usually has an assembler built  
> in.

Not to mention Forth can be compiled to a very minimal memory  
footprint if necessary - even with OO extensions.

>> The point of OOP is that it cleanly encapsulates code and data to  
>> form discrete black boxes. This makes it easier to design complex  
>> systems and ideally reduces the volume of code which has to be  
>> remembered. This can have the added benefit of enabling rapid code  
>> changes, but it's by no means the main advantage.
>> The slow uptake of C++ for system-level coding owes much to the  
>> historic poor performance of compilers in optimising virtual  
>> function calls and the memory footprint of the runtime. In recent  
>> years both considerations have become less important, but in the  
>> embedded sector there is still a preference for assembly language  
>> and imperative languages such as C or BASIC.
>
> There actually was a time when even the use of C was in doubt for  
> embedded systems. An awful lot of Forth, Pascal, PL/M and assembler  
> code was written before C compilers were good enough. Now, of  
> course, the C compilers are good enough to build a high-performance  
> Forth environment in C. :)

Heretic ;p


Ellie

Eleanor McHugh
Games With Brains
http://slides.games-with-brains.net
----
raise ArgumentError unless @reality.responds_to? :reason