Merge pull request #12 from schmrlng/pull-request/19c0a927

Add getindex method for accessing the member variables of ROS types

Author: jdlangs

README.md

@@ -153,6 +153,12 @@ method is not overloaded for objects. In that case, you must call the
 `get_param`, `set_param`, `has_param`, and `delete_param` are all implemented
 in the `RobotOS` module with the same syntax as in rospy.
 
+### Message Constants
+Message constants may be accessed using `getindex` syntax. For example for [visualization_msgs/Marker.msg](http://docs.ros.org/api/visualization_msgs/html/msg/Marker.html) we have:
+
+    import visualization_msgs.msg: Marker
+    Marker[:SPHERE] == getindex(Marker, :SPHERE) == 2   # true
+
 ## ROS Integration
 
 Since Julia code needs no prior compilation, it is possible to integrate very

src/gentypes.jl

@@ -294,7 +294,7 @@ function modulecode(mod::ROSModule)
     push!(modcode,
         quote
             using PyCall
-            import Base.convert
+            import Base: convert, getindex
             import RobotOS
             import RobotOS.Time
             import RobotOS.Duration
@@ -406,6 +406,7 @@ end
 # (2) Default outer constructer with no arguments
 # (3) convert(PyObject, ...)
 # (4) convert(..., o::PyObject)
+# (5) getindex for accessing member constants
 function typecode(rosname::ASCIIString, super::Symbol, members::Vector)
     tname = _splittypestr(rosname)[2]
     @debug("Type: ", tname)
@@ -454,6 +455,10 @@ function typecode(rosname::ASCIIString, super::Symbol, members::Vector)
             jl
         end
     ))
+    #(5) Accessing member variables through getindex
+    push!(exprs, :(
+        getindex(::Type{$jlsym}, s::Symbol) = RobotOS._rospy_objects[$rosname][s]
+    ))
 
     #Now add the meat to the empty expressions above
     for (namestr,typ) in members

test/typegeneration.jl

@@ -3,6 +3,7 @@ using PyCall
 using Compat
 
 @rosimport geometry_msgs.msg: PoseStamped, Vector3
+@rosimport visualization_msgs.msg: Marker
 @rosimport std_srvs.srv.Empty
 @rosimport nav_msgs.srv.GetPlan
 @rosimport std_msgs.msg: Empty
@@ -53,6 +54,9 @@ pose2 = convert(geometry_msgs.msg.PoseStamped, pypose)
 @test pose2.pose.position.z == 3.
 @test_throws InexactError convert(geometry_msgs.msg.Pose, pypose)
 
+#access message enum
+@test visualization_msgs.msg.Marker[:CUBE] == 1
+
 #Proper array handling
 path = nav_msgs.msg.Path()
 @test typeof(path.poses) == Array{geometry_msgs.msg.PoseStamped,1}