Re: ILC2005: McCarthy denounces Common Lisp, "Lisp", XML, and Rahul

Christopher C. Stacy wrote: 
Ray Dillinger <bear@xxxxxxxxx> writes:


C is rare among programming languages in that it takes downward
extensibility as a serious goal and does it well, and C and its
descendants practically rule the earth these days. I think this is not a coincidence.


Contrary to popular belief, the C language does not provide a
way to access low-levels (such as memory locations or registers) of the machine that executes the program. The ISO standard is
quite clear on the fact that C program semantics are defined
in terms of abstract execution environment (eg. "in which issues
of optimization are irrelevant", 5.1.2.3). 

sigh.  I'm not talking about the C spec, I'm talking
about C.

In the real world, C programmers can write subsections
of their programs in machine code and that machine code
will usually run fine even if the C code is compiled
by a different compiler.  It is outside the scope of
the *official* standard, but the data layouts of
structs, etc, are so strongly constrained by tradition
and expectation that they are an *effective* standard.

Hell, the tradition is *so* strong that *binary*
interfaces to OS calls are usually specified these
days in terms of C structs, and the implementors of
code to call those functions from *other languages*
all know exactly what data layout those C structs
refer to and can implement calls to them from other
language systems.

I'm not going to quibble about what's in C's spec.
The spec is (very clearly in this case) not the
language.

				Bear

.

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