Test memmap as input in basic tensor tests

theano/tensor/tests/test_basic.py

 import itertools
 import logging
 import operator
+import os
 import StringIO
 import sys
+from tempfile import mkstemp
 import unittest
 import warnings
 from copy import copy, deepcopy
@@ -176,7 +178,7 @@ def safe_make_node(op, *inputs):
 
 def makeTester(name, op, expected, checks=None, good=None, bad_build=None,
                bad_runtime=None, grad=None, mode=None, grad_rtol=None,
-               eps=1e-10, skip=False):
+               eps=1e-10, skip=False, test_memmap=True):
     if checks is None:
         checks = {}
     if good is None:
@@ -193,6 +195,7 @@ def makeTester(name, op, expected, checks=None, good=None, bad_build=None,
     _op, _expected, _checks, _good = op, expected, checks, good
     _bad_build, _bad_runtime, _grad = bad_build, bad_runtime, grad
     _mode, _grad_rtol, _eps, skip_ = mode, grad_rtol, eps, skip
+    _test_memmap = test_memmap
 
     class Checker(unittest.TestCase):
 
@@ -205,6 +208,48 @@ def makeTester(name, op, expected, checks=None, good=None, bad_build=None,
         grad = _grad
         mode = _mode
         skip = skip_
+        test_memmap = _test_memmap
+
+        def setUp(self):
+            # If test_memmap is True, we create a temporary file
+            # containing a copy of the data passed in the "good" dict,
+            # then open it as a memmapped array, and use the result as a
+            # new test value.
+            # We keep a list of temporary files created, to remove them
+            # at the end of the test.
+            self.tmp_files = []
+            if not self.test_memmap:
+                return
+
+            # Copy dict before modifying them
+            self.good = self.good.copy()
+
+            for k, v in self.good.items():
+                new_k = '_'.join((k, 'memmap'))
+                if new_k in self.good:
+                    # A corresponding key was already provided
+                    break
+
+                new_v = []
+                for inp in v:
+                    if type(inp) is numpy.ndarray and inp.size > 0:
+                        f, fname = mkstemp()
+                        self.tmp_files.append((f, fname))
+                        new_inp = numpy.memmap(fname, dtype=inp.dtype,
+                                mode='w+', shape=inp.shape)
+                        new_inp[...] = inp[...]
+                        new_v.append(new_inp)
+                    else:
+                        new_v.append(copy(inp))
+                self.good[new_k] = new_v
+
+                # We only need one value, no need to copy all of them
+                break
+
+        def tearDown(self):
+            for f, fname in self.tmp_files:
+                os.close(f)
+                os.remove(fname)
 
         def test_good(self):
             if skip: