[Python-Dev] Prospective Peephole Transformation

Raymond Hettinger python at rcn.com
Sat Feb 19 05:47:01 CET 2005

> I'm very glad you introduced the optimization of building small
> constant tuples at compile-time.  IMO, that was a pure win.

It's been out in the wild for a while now with no issues.  I'm somewhat
happy with it.

>  the transformation isn't semantically correct on the
> face of it.

Well that's the end of that.

What we really need is a clean syntax for specifying a constant
frozenset without compiler transformations of tuples.  That would have
the further advantage of letting builtins and globals be used as element

   if isinstance(x, {int, float, complex}):
   if opcode in {REPEAT, MIN_REPEAT, MAX_REPEAT}:
   if (code in {301, 302, 303, 307} and m in {"GET", "HEAD"}:
   if op in (ROT_TWO, POP_TOP, LOAD_FAST)

Perhaps something other notation would be better but the idea is
basically the same.


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