[pypy-svn] r56425 - in pypy/dist/pypy/module/itertools: . test

[jlg at codespeak.net]

Author: jlg
Date: Thu Jul 10 19:14:43 2008
New Revision: 56425

Modified:
   pypy/dist/pypy/module/itertools/__init__.py
   pypy/dist/pypy/module/itertools/interp_itertools.py
   pypy/dist/pypy/module/itertools/test/test_itertools.py
Log:
(adurdin, jlg) interp_itertools - islice partialy implemented

Modified: pypy/dist/pypy/module/itertools/__init__.py
==============================================================================
--- pypy/dist/pypy/module/itertools/__init__.py	(original)
+++ pypy/dist/pypy/module/itertools/__init__.py	Thu Jul 10 19:14:43 2008
@@ -9,6 +9,7 @@
         'dropwhile' : 'interp_itertools.W_DropWhile',
         'ifilter'   : 'interp_itertools.W_IFilter',
         'ifilterfalse' : 'interp_itertools.W_IFilterFalse',
+        'islice'    : 'interp_itertools.W_ISlice',
         'repeat'    : 'interp_itertools.W_Repeat',
         'takewhile' : 'interp_itertools.W_TakeWhile',
     }

Modified: pypy/dist/pypy/module/itertools/interp_itertools.py
==============================================================================
--- pypy/dist/pypy/module/itertools/interp_itertools.py	(original)
+++ pypy/dist/pypy/module/itertools/interp_itertools.py	Thu Jul 10 19:14:43 2008
@@ -276,3 +276,60 @@
                 yield x
     """)
 
+class W_ISlice (Wrappable):
+
+    def __init__(self, space, w_iterable, start, stop, step):
+        self.iterable = space.iter(w_iterable)
+        self.space = space
+        if stop == -1:
+            stop = start
+            start = 0
+
+        if step == -1:
+            step = 1
+
+        self.start = start
+        self.stop = stop
+        self.step = step
+
+    def iter_w(self):
+        return self.space.wrap(self)
+
+    def next_w(self):
+        if self.stop <= 0:
+            raise OperationError(self.space.w_StopIteration, self.space.w_None)
+
+        if self.start >= 0:
+            skip = self.start
+            self.start = -1
+        else:
+            skip = self.step - 1
+
+        try:
+            while skip > 0:
+                self.space.next(self.iterable)
+                skip -= 1
+                self.stop -= 1
+
+        except StopIteration:
+            raise OperationError(self.space.w_StopIteration, self.space.w_None)
+
+        try:
+            w_obj = self.space.next(self.iterable)
+        except StopIteration:
+            raise OperationError(self.space.w_StopIteration, self.space.w_None)
+
+        self.stop -= 1
+        return w_obj
+
+def W_ISlice___new__(space, w_subtype, w_iterable, start, stop, step):
+    # TODO varible arguments number not implemented (optional start, step)
+    return space.wrap(W_ISlice(space, w_iterable, start, stop, step))
+
+W_ISlice.typedef = TypeDef(
+        'islice',
+        __new__  = interp2app(W_ISlice___new__, unwrap_spec=[ObjSpace, W_Root, W_Root, int, int, int]),
+        __iter__ = interp2app(W_ISlice.iter_w, unwrap_spec=['self']),
+        next     = interp2app(W_ISlice.next_w, unwrap_spec=['self']),
+        __doc__  = "")
+

Modified: pypy/dist/pypy/module/itertools/test/test_itertools.py
==============================================================================
--- pypy/dist/pypy/module/itertools/test/test_itertools.py	(original)
+++ pypy/dist/pypy/module/itertools/test/test_itertools.py	Thu Jul 10 19:14:43 2008
@@ -14,6 +14,7 @@
             itertools.dropwhile(bool, []),
             itertools.ifilter(None, []),
             itertools.ifilterfalse(None, []),
+            itertools.islice([], 0, -1, -1),
             ]
 
         for it in iterables:
@@ -185,3 +186,44 @@
 
         raises(TypeError, itertools.ifilterfalse, bool, None)
 
+    def test_islice(self):
+        import itertools
+
+        it = itertools.islice([], 0, -1, -1)
+        raises(StopIteration, it.next)
+
+        it = itertools.islice([1, 2, 3], 0, -1, -1)
+        raises(StopIteration, it.next)
+
+        it = itertools.islice([1, 2, 3, 4, 5], 3, -1, -1)
+        for x in [1, 2, 3]:
+            assert it.next() == x
+        raises(StopIteration, it.next)
+
+        it = itertools.islice([1, 2, 3, 4, 5], 3, -1, -1)
+        for x in [1, 2, 3]:
+            assert it.next() == x
+        raises(StopIteration, it.next)
+
+        it = itertools.islice([1, 2, 3, 4, 5], 1, 3, -1)
+        for x in [2, 3]:
+            assert it.next() == x
+        raises(StopIteration, it.next)
+
+        it = itertools.islice([1, 2, 3, 4, 5], 0, 3, 2)
+        for x in [1, 3]:
+            assert it.next() == x
+        raises(StopIteration, it.next)
+
+    def test_islice_overflow(self):
+        import itertools
+        import sys
+
+        raises(OverflowError, itertools.islice, [], sys.maxint + 1, -1, -1)
+
+    def test_islice_wrongargs(self):
+        import itertools
+
+        raises(TypeError, itertools.islice, [], None, -1, -1)
+        raises(TypeError, itertools.islice, None, 0, -1, -1)
+