support float('inf') for cfg file (ros#168)

* support float('inf') for cfg file

* add float in test.cft g

Author: knorth55

cfg/Test.cfg

@@ -51,6 +51,8 @@ gen.add("int_", int_t, 1, "Int parameter",0, -10, 10)
 gen.add("double_", double_t, 2, "double parameter", 0, -2, 10)
 gen.add("double_no_minmax", double_t, 2, "double parameter without boundaries", 1)
 gen.add("double_no_max", double_t, 2, "double parameter without max value", 2, 0)
+gen.add("double_inf", double_t, 2, "double parameter with inf", float('inf'), float('inf'), float('inf'))
+gen.add("double_negative_inf", double_t, 2, "double parameter with negative inf", -float('inf'), -float('inf'), -float('inf'))
 gen.add("str_", str_t, 4, "String parameter","foo")
 gen.add("mstr_", str_t, 4, "Multibyte String parameter","bar")
 gen.add("bool_", bool_t, 8, "Boolean parameter",False)

src/dynamic_reconfigure/parameter_generator_catkin.py

@@ -404,8 +404,15 @@ def crepr(self, param, val):
         type = param["type"]
         if type == 'str':
             return '"' + val + '"'
-        if type in ['int', 'double']:
+        if type == 'int':
             return str(val)
+        if type == 'double':
+            if val == float('inf'):
+                return 'std::numeric_limits<double>::infinity()'
+            elif val == -float('inf'):
+                return '-std::numeric_limits<double>::infinity()'
+            else:
+                return str(val)
         if type == 'bool':
             return {True: 1, False: 0}[val]
         raise TypeError(type)