🚀 go-pugleaf

hrubin@mentor.cc.purdue.edu (Herman Rubin) writes:
>There IS a way to get some of this, and I have been assured by those
>who supposedly know that this can even be done, and at not too great
>a cost.  That is to allow a really powerful macro language, which 
>would be a syntactical translator from what the user wants to write
>to what some processor can read.  

This is going back 30 years. There was a project at Cambridge (I think, or
maybe Oxford) on a General Purpose MacroGenerator (GPM). This developed a
language called CPL, which I gather was the forerunner of ideas that went
into BCPL, then into B and into C. However, those who worked on this
realised how much further they could push these ideas and took off more
in the direction of HLLs. After all instructions in a language are just
macros. But with a compiler you can achieve much more than just generate
machine code. In fact generation of machine code becomes a somewhat
secondary function compared to helping organise software, and automatically
do proof checking on it. Chris Reade in his book "Elements of Functional
Programming" has some good comments on these more important functions of
languages and compilers.

P.S. I basically disagreed with your car analogies. I think the level of
control over raw machine resources that you are advocating would be rather
like braking a car by sticking your feet through the floor, rather like
the Flintstones. Saying that a compiler writer is like a mechanic who
does not know how a car works is the opposite of reality.

A compiler is actually more like the controls in a car. The pedals, steering
wheel, and other controls in a car, 'compile' your intentions into something
that the car understands. That is because the designer of a car understands
how the car works, so that everyone who drives the car does not need to.
A compiler writer in fact also has intimate understanding of the underlying
machine, so that every programmer does not need to. However, if they are
really interested, they can find out about this level. And when they
really understand it, then they realise you don't need to know a lot
about how hardware works, but that this *is* best left to a compiler.
-- 
Ian Joyner  ACUS (Australian Centre for Unisys Software)    ian@syacus.acus.oz
"Where is the man with all the great directions?...You can't imagine it,
 how hard it is to grow, Can you imagine the order of the universe?" ABWH
Disclaimer:Opinions and comments are personal.