[Cython] Feature Request: expand list/tuple in 'if (... in ...):' ...

[Dag Sverre Seljebotn]

On 01/24/2013 03:13 PM, Christian Inci wrote:
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> Subject: Feature Request: expand list/tuple in 'if (... in ...):' ...
>
> expand list/tuple in 'if (... in ...):' on compile-time if the list/tuple contains only static values.
>
> test1: list is expanded manually.
> test2: list is not expanded.
>
> The output of the testcase is:
> test1: timediff: 0.205533
> test2: timediff: 17.567185
>
>
> Testcase:
>
> from time import time
>
> cdef tuple INT_TUPLE = (0x66, 0x67, 0x2e,
>                   0x36, 0x3e, 0x26, 0x64,
>                   0x65, 0xf2, 0xf3, 0xf0)

How do you know that INT_TUPLE isn't reassigned to something else?

Dag Sverre

>
> cpdef test():
>      cdef unsigned int i
>      cdef unsigned short j # 'unsigned char j' won't work for some reason
>      cdef double start_time
>      start_time = time()
>      for i in range(0x50000):
>          for j in range(256):
>              if (j == 0x66 or j == 0x67 or j == 0x2e or j == 0x36 or j == 0x3e or j == 0x26 or j == 0x64 or j == 0x65 or j == 0xf2 or j == 0xf3 or j == 0xf0):
>                  pass
>      print("test1: timediff: {0:f}".format(time()-start_time))
>      start_time = time()
>      for i in range(0x50000):
>          for j in range(256):
>              if (j in INT_TUPLE):
>                  pass
>      print("test2: timediff: {0:f}".format(time()-start_time))
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