numba recursion

Note that an explicit type signature is required at the moment for Numba's recursion support to work

NG

code:python

import sys

import numba

def recur(t):

if t == 0:

return 1

return t * recur(t - 1)

print("compiling")

from numba.pycc import CC

cc = CC('my_module')

cc.export('recur', 'i8(i8)')(recur)

cc.compile()

else:

from my_module import recur

print(recur(5))

code::

Untyped global name 'recur': cannot determine Numba type of <class 'function'>

File "numbatest.py", line 7:

def recur(t):

<source elided>

return 1

return t * recur(t - 1)

^

OK

code:python

@numba.njit("i8(i8)")

def recur(t):

NG

code:python

def main(x):

def recur(t):

Not Supported

Numba now supports inner functions as long as they are non-recursive and only called locally, but not passed as argument or returned as result. The use of closure variables (variables defined in outer scopes) within an inner function is also supported.