On-topic: alternate Python implementations

[John Nagle]

There are other approaches. PyPy uses two interpreters and a JIT
compiler to handle the hard cases. When code does something unexpected
to other code, the backup interpreter is used to get control out of
the trouble spot so that the JIT compiler can then recompile the
code. (I think; I've read the paper but haven't looked at the
internals.)

This is hard to implement and hard to get right.

John Nagle

 

[Ulrich Eckhardt]

Am 04.08.2012 15:53, schrieb Stefan Behnel:

So, if a C++ compiler takes a .c file and compiles it with C language
semantics, it doesn't qualify as a C compiler? That implies a rather weird
definition of a C compiler, I'd say.

I'd say that even a brainfuck compiler compiling a .py file with C
language semantics can shamelessly call itself a C compiler.

If a C++ compiler is given C code, it may or may not produce equivalent
executables. In most non-trivial cases it will just barf on the valid C
/ invalid C++ code and refuse to compile it. In few rare cases, it will
compile the code and produce different behaviour at runtime (e.g. for
"sizeof 'a'").


Uli