Add null support for constants and defaults

rosidl_generator_py/resource/_msg.py.em

@@ -46,7 +46,7 @@ for member in message.structure.members:
  'import builtins', []) # used for @builtins.property
  if isinstance(type_, BasicType) and type_.typename in FLOATING_POINT_TYPES:
  imports.setdefault(
- 'import math', []) # used for math.isinf
+ 'import math', []) # used for math.isinf, math.nan
  if (
  isinstance(member.type, AbstractNestedType) and
  isinstance(member.type.value_type, BasicType) and
@@ -405,6 +405,11 @@ if isinstance(type_, AbstractNestedType):
  if all(self.@(member.name) != other.@(member.name)):
 @[ else]@
  if self.@(member.name) != other.@(member.name):
+@[ if isinstance(member.type, BasicType) and member.type.typename in FLOATING_POINT_TYPES ]@
+ # Handle special case for IEE-754 floating point NaN not equaling itself.
+ if math.isnan(self.@(member.name)) and math.isnan(other.@(member.name)):
+ return True
+@[ end if]@
 @[ end if]@
  return False
 @[end for]@

rosidl_generator_py/rosidl_generator_py/generate_py_impl.py

@@ -14,6 +14,7 @@
 
 from ast import literal_eval
 import keyword
+import math
 import os
 import pathlib
 import sys
@@ -246,7 +247,7 @@ def primitive_value_to_py(type_, value):
  return repr(bytes([value]))
 
  if type_.typename in FLOATING_POINT_TYPES:
- return '%s' % value
+ return floating_point_to_py(value)
 
  assert False, "unknown primitive type '%s'" % type_.typename
 
@@ -268,14 +269,21 @@ def constant_value_to_py(type_, value):
  return repr(bytes([value]))
 
  if type_.typename in FLOATING_POINT_TYPES:
- return '%s' % value
+ return floating_point_to_py(value)
 
  if isinstance(type_, AbstractGenericString):
  return quoted_string(value)
 
  assert False, "unknown constant type '%s'" % type_
 
 
+def floating_point_to_py(value):
+ if math.isnan(float(value)):
+ return 'math.nan'
+ else:
+ return '%s' % value
+
+
 def quoted_string(s):
  s = s.replace('\\', '\\\\')
  # strings containing single quote but no double quotes can be wrapped in

rosidl_generator_py/test/test_generate_py_impl.py

@@ -0,0 +1,28 @@
+# Copyright 2016-2019 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+# http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+from rosidl_generator_py.generate_py_impl import floating_point_to_py
+
+
+def test_floating_point_to_py():
+
+ # normal floating point values
+ assert floating_point_to_py("1.0") == "1.0"
+ assert floating_point_to_py("-42.0") == "-42.0"
+
+ # NaN's
+ assert floating_point_to_py("NaN") == "math.nan"
+ assert floating_point_to_py("nan") == "math.nan"
+ assert floating_point_to_py("NAN") == "math.nan"

rosidl_generator_py/test/test_interfaces.py

@@ -83,8 +83,12 @@ def test_basic_types():
  assert 42 == msg.char_value
  msg.float32_value = 1.125
  assert 1.125 == msg.float32_value
+ msg.float32_value = math.nan
+ assert math.isnan(msg.float32_value)
  msg.float64_value = 1.125
  assert 1.125 == msg.float64_value
+ msg.float64_value = math.nan
+ assert math.isnan(msg.float64_value)
  msg.int8_value = -50
  assert -50 == msg.int8_value
  msg.uint8_value = 200
@@ -130,22 +134,29 @@ def test_basic_types():
  setattr(msg, 'float64_value', float64_ieee_max_next)
 
  # NaN
+ # Test IEEE-754 message equality when values are NaN.
  setattr(msg, 'float32_value', math.nan)
  assert math.isnan(msg.float32_value)
+ assert msg == msg
  setattr(msg, 'float64_value', math.nan)
  assert math.isnan(msg.float64_value)
+ assert msg == msg
 
  # -Inf
  setattr(msg, 'float32_value', -math.inf)
  assert math.isinf(msg.float32_value)
+ assert msg == msg
  setattr(msg, 'float64_value', -math.inf)
  assert math.isinf(msg.float64_value)
+ assert msg == msg
 
  # +Inf
  setattr(msg, 'float32_value', math.inf)
  assert math.isinf(msg.float32_value)
+ assert msg == msg
  setattr(msg, 'float64_value', math.inf)
  assert math.isinf(msg.float64_value)
+ assert msg == msg
 
 
 def test_strings():