Paragon Adrift

A cursory reflection upon the senses.

Mar
25th

Wed

With the infrastructure to generate machine code comes the possibility of compiling Python into a much more efficient implementation. For example, take the snippet


for i in range(3):
  foo(i)

This currently desugars to something like


$x = range(3)
while True:
  try:
    i = $x.next()
  except StopIteration:
    break
  foo(i)

Once we have a mechanism to know that range() means the range() builtin function, we can turn this into something more akin to


for (i = 0; i

in C, possibly using unboxed types for the math. We can then unroll the loop to yield


foo(0)
foo(1)
foo(2)

— Project Plan for Python’s Unladen-Swallow optimization branch #