fix issue #229 enable round-trip of floats without number before the dot

[ .5, -.5, +.5 ] should work

*When this change indeed resolves your problem, please **Close** this issue*.
*(You can do so using the WorkFlow pull-down (close to the top right of this page))*

3 files changed, 7 insertions, 3 deletions

diff --git a/_test/test_float.py b/_test/test_float.py
index 2012b15..1f104f3 100644
--- a/_test/test_float.py
+++ b/_test/test_float.py
@@ -22,6 +22,8 @@ class TestFloat:
         - -42.
         - +42.
         - .5
+        - +.5
+        - -.5
         """)
         print(data)
         assert 0.999 < data[0] < 1.001
@@ -34,6 +36,8 @@ class TestFloat:
         assert 41.999 < -data[7] < 42.001
         assert 41.999 < data[8] < 42.001
         assert .49 < data[9] < .51
+        assert .49 < data[10] < .51
+        assert -.51 < data[11] < -.49
 
     def test_round_trip_zeros_0(self):
         data = round_trip("""\
diff --git a/representer.py b/representer.py
index 6bd5651..dba7901 100644
--- a/representer.py
+++ b/representer.py
@@ -788,13 +788,13 @@ class RoundTripRepresenter(SafeRepresenter):
         elif data._exp is None:
             # no exponent, "normal" dot
             prec = data._prec
-            if prec < 1:
-                prec = 1
             ms = data._m_sign if data._m_sign else ""
             # -1 for the dot
             value = u'{}{:0{}.{}f}'.format(
                 ms, abs(data), data._width - len(ms), data._width - prec - 1
             )
+            if prec == 0 or (prec == 1 and ms != ""):
+                value = value.replace(u'0.', u'.')
             while len(value) < data._width:
                 value += u'0'
         else:
diff --git a/resolver.py b/resolver.py
index bada11e..2641a54 100644
--- a/resolver.py
+++ b/resolver.py
@@ -38,7 +38,7 @@ implicit_resolvers = [
         RegExp(u'''^(?:
          [-+]?(?:[0-9][0-9_]*)\\.[0-9_]*(?:[eE][-+]?[0-9]+)?
         |[-+]?(?:[0-9][0-9_]*)(?:[eE][-+]?[0-9]+)
-        |\\.[0-9_]+(?:[eE][-+][0-9]+)?
+        |[-+]?\\.[0-9_]+(?:[eE][-+][0-9]+)?
         |[-+]?\\.(?:inf|Inf|INF)
         |\\.(?:nan|NaN|NAN))$''', re.X),
         list(u'-+0123456789.')),