2009/3/18 Anoop Saldanha <[email protected]>:
[snip]
>
> But
>
> cdef int g():
> print "g called"
> return 5
>
> def f():
> cdef int i
> for i in range(g()):
> print i
> print i
>
> uses a ForFromStatNode for the "for in" loop!
I'm not a core developer, so this is open to correction, but putting
in some PrintTree() calls into
Cython/Compiler/Main.py:create_pipeline() shows that it starts out as
a ForInStatNode and is changed to a ForFromStatNode. Perhaps because
cython inferrs that g returns a C int and it triggers the 'range'
optimization.
Before any transformations:
- (root): ModuleNode(pos=(foo.pyx:1:0))
- body: StatListNode(pos=(foo.pyx:1:0))
- stats[0]: CFuncDefNode(pos=(foo.pyx:1:5))
[removing cdef int g() stuff]
- stats[1]: DefNode(name="f")
- body: StatListNode(pos=(foo.pyx:6:4))
- stats[0]: CVarDefNode(pos=(foo.pyx:6:9))
- base_type: CSimpleBaseTypeNode(pos=(foo.pyx:6:9))
- declarators[0]: CNameDeclaratorNode(pos=(foo.pyx:6:13))
- stats[1]: ForInStatNode(pos=(foo.pyx:8:4)) <== starts out as
as ForInStatNode
[snip rest of def f() function body]
After all transformations:
- (root): ModuleNode(pos=(foo.pyx:1:0))
- body: StatListNode(pos=(foo.pyx:1:0))
- stats[0]: CFuncDefNode(pos=(foo.pyx:1:5))
[snip func body]
- stats[1]: DefNode(name="f")
- body: StatListNode(pos=(foo.pyx:6:4))
- stats[0]: ForFromStatNode(pos=(foo.pyx:8:4)) <== Changed to
a ForFromStatNode.
- target: NameNode(type=<CNumericType int>, name="i")
- bound1: IntNode(type=<CNumericType long>)
- bound2: SimpleCallNode(type=<CNumericType int>)
- function: NameNode(type=<CFuncType <CNumericType int>
[]>, name="g")
- step: IntNode(type=<CNumericType long>)
- body: StatListNode(pos=(foo.pyx:9:8))
- stats[0]: PrintStatNode(pos=(foo.pyx:9:8))
- arg_tuple: TupleNode(type=<PyTuple_Type>)
- args[0]: CoerceToPyTypeNode(type=<PyObjectType>)
- arg: NameNode(type=<CNumericType int>, name="i")
- stats[1]: PrintStatNode(pos=(foo.pyx:10:4))
- arg_tuple: TupleNode(type=<PyTuple_Type>)
- args[0]: CoerceToPyTypeNode(type=<PyObjectType>)
- arg: NameNode(type=<CNumericType int>, name="i")
Kurt
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