Compile Time Static Evaluations

[sirinath]

The following example given in the readme should ideally take very little time as the compiler would be able to optimize away the calculation at compile time and just do printing only.

from time import time

def fib(n):
    return n if n < 2 else fib(n - 1) + fib(n - 2)

t0 = time()
ans = fib(40)
t1 = time()
print(f'Computed fib(40) = {ans} in {t1 - t0} seconds.')

Only code which are input dependent should need runtime evaluation. Partly dependent code can be partly evaluated at compile time. Any code which is not dependent on any input ideally should be optimized away at higher optimization settings with possible slower compilation time, but should be optimized for compile time evaluations.

[arshajii]

FYI it's possible to do this with Codon's Literal[int] type:

def fib(n: Literal[int]) -> Literal[int]:
    return n if n < 2 else fib(n - 1) + fib(n - 2)

Then fib(40) will be evaluated to a constant integer at compile-time.

[sirinath]

I believe the compiler should be able to partly or completely evaluate any expressions at compile time that is not IO dependent without any special construct like this. Only IO dependent code should be evaluated at runtime.