Make maxsize available for python < 2.6, use it

theano/gof/python25.py

@@ -130,5 +130,22 @@ if sys.version_info[:2] < (2,6):
         for prod in result:
             yield tuple(prod)
 
+    # For maxsize
+    class __Dummy(object):
+        """
+        Dummy class used to know what is the max index of a slice.
+
+        This way, we do not have to rely on guesses for untested
+        architectures.
+        """
+        def __getslice__(self, *args):
+            return args
+
+    # This "slice" should be a (1, maxsize) tuple
+    __dummy_slice = __Dummy()[1:]
+    maxsize = __dummy_slice[1]
+    del __dummy_slice, __Dummy
+
 else:
     from itertools import combinations, product
+    from sys import maxsize

theano/scan_module/scan_opt.py

@@ -14,12 +14,12 @@ __contact__ = "Razvan Pascanu <r.pascanu@gmail>"
 
 import logging
 import numpy
-import sys
 
 import theano
 from theano import tensor
 from theano.tensor import opt, get_constant_value
 from theano import gof
+from theano.gof.python25 import maxsize
 from theano.compile import optdb
 from theano import config
 from theano.compile.function_module import deep_copy_op
@@ -497,7 +497,7 @@ class ScanSaveMem(gof.Optimizer):
                         stop = tensor.basic.extract_constant(cf_slice[0].stop)
                     else:
                         stop = tensor.basic.extract_constant(cf_slice[0]) + 1
-                    if stop == sys.maxsize or stop == length:
+                    if stop == maxsize or stop == length:
                         stop = None
                     else:
                         # there is a **gotcha** here ! Namely, scan returns an
@@ -517,7 +517,7 @@ class ScanSaveMem(gof.Optimizer):
                             global_nsteps['sym'] += [stop]
                         # not if it is maxsize
                         elif (type(stop) in (int, long) and
-                              stop == sys.maxsize):
+                              stop == maxsize):
                             global_nsteps = None
                         # yes if it is a int k, 0 < k < maxsize
                         elif (type(stop) in (int, long) and
@@ -756,7 +756,7 @@ class ScanSaveMem(gof.Optimizer):
                             start = (cnf_slice[0].start - nw_steps -
                                      init_l[pos] + store_steps[pos])
                             if (cnf_slice[0].stop is not None and
-                                cnf_slice[0].stop != sys.maxsize):
+                                cnf_slice[0].stop != maxsize):
                                 stop = (cnf_slice[0].stop - nw_steps -
                                         init_l[pos] + store_steps[pos])
                             else:

theano/tensor/basic.py

@@ -3,7 +3,7 @@
 __docformat__ = "restructuredtext en"
 
 import __builtin__
-import sys  # for sys.maxsize
+import sys
 from theano.configparser import config
 import warnings
 from itertools import izip
@@ -17,7 +17,7 @@ from theano.gof import Apply, Constant, Op, Type, Value, Variable
 
 import elemwise
 from theano import scalar as scal
-from theano.gof.python25 import partial, any, all
+from theano.gof.python25 import partial, any, all, maxsize
 from theano import compile, printing
 from theano.printing import pprint, min_informative_str
 from theano.tensor.utils import hash_from_ndarray
@@ -3124,7 +3124,7 @@ def get_canonical_form_slice(theslice, length):
             start = switch(ge(start,length)
                            , switch(lt(step,0),length-1,length)
                            , start)
-        if stop in [None, sys.maxsize]:
+        if stop in [None, maxsize]:
             # The special "maxsize" case is probably not needed here,
             # as slices containing maxsize are not generated by
             # __getslice__ anymore.
@@ -3249,7 +3249,7 @@ class Subtensor(Op):
             else:
                 slice_a = None
 
-            if b is not None and b != sys.maxsize:
+            if b is not None and b != maxsize:
                 # The special "maxsize" case is probably not needed here,
                 # as slices containing maxsize are not generated by
                 # __getslice__ anymore.
@@ -3350,7 +3350,7 @@ class Subtensor(Op):
                 # If it is the default (None, None, None) slice, or a variant,
                 # the shape will be xl
                 if ( (idx.start in [None, 0])
-                    and (idx.stop in [None, sys.maxsize])
+                    and (idx.stop in [None, maxsize])
                     and (idx.step is None or idx.step == 1) ):
                     outshp.append(xl)
                 else:
@@ -3424,7 +3424,7 @@ class Subtensor(Op):
         is_slice = []
         #TODO: change that, it might lead to unexpected results,
         # see assembla-#767
-        NONE_CODE = sys.maxsize - 1
+        NONE_CODE = maxsize - 1
 
         pos = [0,1] #annoying version of global variable for init_entry
         def inc_spec_pos(amt): pos[0] += amt
@@ -3698,7 +3698,7 @@ class SubtensorPrinter:
                     else:
                         msg1 =  entry.start
 
-                    if entry.stop is None or entry.stop == sys.maxsize:
+                    if entry.stop is None or entry.stop == maxsize:
                         msg2 = ""
                     else:
                         msg2 =  entry.stop

theano/tensor/opt.py

@@ -20,6 +20,7 @@ import theano
 from theano import gof
 from theano.gof import opt, InconsistencyError, TopoOptimizer, graph
 from theano.gof import Variable, Constant
+from theano.gof.python25 import maxsize
 from theano.gof.utils import MethodNotDefined
 from theano.configparser import config
 from elemwise import Elemwise, DimShuffle
@@ -1507,7 +1508,7 @@ def local_useless_subtensor(node):
                 # is not a useless subtensor
                 return False
 
-            length_pos_data = sys.maxsize
+            length_pos_data = maxsize
 
             length_pos = shape_of[node.inputs[0]][pos]
             try: