Revamp the inf/nan handling again.

git-svn-id: http://svn.pyyaml.org/pyyaml/trunk@173 18f92427-320e-0410-9341-c67f048884a3

5 files changed, 27 insertions, 17 deletions

diff --git a/lib/yaml/constructor.py b/lib/yaml/constructor.py
index e35cca7..0d1bb19 100644
--- a/lib/yaml/constructor.py
+++ b/lib/yaml/constructor.py
@@ -232,9 +232,9 @@ class SafeConstructor(BaseConstructor):
             return sign*int(value)
 
     inf_value = 1e300
-    while repr(inf_value) != repr(inf_value*inf_value):
+    while inf_value != inf_value*inf_value:
         inf_value *= inf_value
-    nan_value = inf_value/inf_value
+    nan_value = -inf_value/inf_value   # Trying to make a quiet NaN (like C99).
 
     def construct_yaml_float(self, node):
         value = str(self.construct_scalar(node))
diff --git a/lib/yaml/reader.py b/lib/yaml/reader.py
index beb76d0..e9c34b1 100644
--- a/lib/yaml/reader.py
+++ b/lib/yaml/reader.py
@@ -120,9 +120,11 @@ class Reader:
             self.determine_encoding()
 
     def peek(self, index=0):
-        if self.pointer+index+1 >= len(self.buffer):
+        try:
+            return self.buffer[self.pointer+index]
+        except IndexError:
             self.update(index+1)
-        return self.buffer[self.pointer+index]
+            return self.buffer[self.pointer+index]
 
     def prefix(self, length=1):
         if self.pointer+length >= len(self.buffer):
@@ -132,7 +134,7 @@ class Reader:
     def forward(self, length=1):
         if self.pointer+length+1 >= len(self.buffer):
             self.update(length+1)
-        for k in range(length):
+        while length:
             ch = self.buffer[self.pointer]
             self.pointer += 1
             self.index += 1
@@ -142,6 +144,7 @@ class Reader:
                 self.column = 0
             elif ch != u'\uFEFF':
                 self.column += 1
+            length -= 1
 
     def get_mark(self):
         if self.stream is None:
diff --git a/lib/yaml/representer.py b/lib/yaml/representer.py
index b78c882..932dede 100644
--- a/lib/yaml/representer.py
+++ b/lib/yaml/representer.py
@@ -195,22 +195,16 @@ class SafeRepresenter(BaseRepresenter):
     inf_value = 1e300
     while repr(inf_value) != repr(inf_value*inf_value):
         inf_value *= inf_value
-    nan_value = inf_value/inf_value
-
-    repr_pos_inf = repr(inf_value)
-    repr_neg_inf = repr(-inf_value)
-    repr_nan = repr(inf_value/inf_value)
 
     def represent_float(self, data):
-        repr_data = repr(data)
-        if repr_data == self.repr_pos_inf:
+        if data != data or (data == 0.0 and data == 1.0):
+            value = u'.nan'
+        elif data == self.inf_value:
             value = u'.inf'
-        elif repr_data == self.repr_neg_inf:
+        elif data == -self.inf_value:
             value = u'-.inf'
-        elif repr_data == self.repr_nan:
-            value = u'.nan'
         else:
-            value = unicode(repr_data)
+            value = unicode(repr(data))
         return self.represent_scalar(u'tag:yaml.org,2002:float', value)
 
     def represent_list(self, data):
diff --git a/tests/test_constructor.py b/tests/test_constructor.py
index efbdbd4..cd6695f 100644
--- a/tests/test_constructor.py
+++ b/tests/test_constructor.py
@@ -261,7 +261,17 @@ class TestConstructorTypes(test_appliance.TestAppliance):
                     data2 = [(repr(key), value) for key, value in data2.items()]
                     data2.sort()
                     data2 = repr(data2)
-                if data1 != data2:
+                    if data1 != data2:
+                        raise
+                elif isinstance(data1, list):
+                    self.failUnlessEqual(type(data1), type(data2))
+                    self.failUnlessEqual(len(data1), len(data2))
+                    for item1, item2 in zip(data1, data2):
+                        if (item1 != item1 or (item1 == 0.0 and item1 == 1.0)) and  \
+                                (item2 != item2 or (item2 == 0.0 and item2 == 1.0)):
+                            continue
+                        self.failUnlessEqual(item1, item2)
+                else:
                     raise
         except:
             print
diff --git a/tests/test_representer.py b/tests/test_representer.py
index e0fa894..8097733 100644
--- a/tests/test_representer.py
+++ b/tests/test_representer.py
@@ -33,6 +33,9 @@ class TestRepresenterTypes(test_appliance.TestAppliance):
                     self.failUnlessEqual(type(data1), type(data2))
                     self.failUnlessEqual(len(data1), len(data2))
                     for item1, item2 in zip(data1, data2):
+                        if (item1 != item1 or (item1 == 0.0 and item1 == 1.0)) and  \
+                                (item2 != item2 or (item2 == 0.0 and item2 == 1.0)):
+                            continue
                         self.failUnlessEqual(item1, item2)
                 else:
                     raise