Module roslua.msg_spec
Message specification. This module contains the MsgSpec class to read and represent ROS message specification (YAML files). Message specifications should be obtained by using the get_msgspec() function, which is aliased for convenience as roslua.get_msgspec().
The message files are read on the fly, no offline code generation is necessary. This avoids the need to write yet another code generator. After reading the table field fields contains key value pairs, where the keys are the names of the data fields and the value is the type of the data field.
Copyright© Tim Niemueller, Carnegie Mellon University, Intel Research Pittsburgh
Release: Released under BSD license
Functions
| MsgSpec:instantiate (no_prefill) | Instantiate this message. |
| MsgSpec:is_instance (message) | Check if given message is an instance of this spec. |
| MsgSpec:load () | Load message specification from file. |
| MsgSpec:load_from_string (s) | Load specification from string. |
| MsgSpec:md5 () | Get MD5 sum of type specification. |
| MsgSpec:new (o) | Contstructor. |
| MsgSpec:print (indent) | Print specification. |
| MsgSpec:resolve_type (type) | Resolve a type relative to this message spec. |
| base_type (type) | Get the base version of type, i.e. |
| get_msgspec (msg_type, specstr) | Get message specification. |
| is_array_type (type) | Check if type is an array type. |
| is_builtin_type (type) | Check if given type is a built-in type. |
| is_msgspec (testobj) | Check if the given object is a message spec. |
| resolve_type (type, package) | Resolve the given type. |
Functions
- MsgSpec:instantiate (no_prefill)
-
Instantiate this message.
Parameters
- no_prefill:
Return value:
a Message instance of the specified message type.See also:
- MsgSpec:is_instance (message)
-
Check if given message is an instance of this spec.
Parameters
- message: message instance to check
Return value:
true if the message is an instantiation of this spec, false otherwise - MsgSpec:load ()
- Load message specification from file. Will search for the appropriate message specification file (using rospack) and will then read and parse the file.
- MsgSpec:load_from_string (s)
-
Load specification from string.
Parameters
- s: string containing the message specification
- MsgSpec:md5 ()
-
Get MD5 sum of type specification. This will create a text representation of the message specification and generate the MD5 sum for it. The value is cached so concurrent calls will cause the cached value to be returned
Return value:
MD5 sum of message specification - MsgSpec:new (o)
-
Contstructor.
Parameters
- o: Object initializer, must contain a field type with the string representation of the type name. Optionally can contain a specstr field, in which case the string will be parsed as message specification and no attempt will be made to read the message specification file.
- MsgSpec:print (indent)
-
Print specification.
Parameters
- indent: string (normally spaces) to put before every line of output
- MsgSpec:resolve_type (type)
-
Resolve a type relative to this message spec. This is similar to the global resolve_type function, but the package parameter can be omitted as it is taken from the message spec instance.
Parameters
- type: type to resolve
Return value:
resolved typeSee also:
- base_type (type)
-
Get the base version of type, i.e. the non-array type.
Parameters
- type: type to get base type for
Return value:
base type, for array types returns the non-array type, for non-array type returns the given value. - get_msgspec (msg_type, specstr)
-
Get message specification. It is recommended to use the aliased version
roslua.get_msgspec().Parameters
- msg_type: message type (e.g. std_msgs/String). The name must include the package.
- specstr:
- is_array_type (type)
-
Check if type is an array type.
Parameters
- type: type to check
Return value:
true if given type is an array type, false otherwise - is_builtin_type (type)
-
Check if given type is a built-in type.
Parameters
- type: type to check
Return value:
true if type is a built-in type, false otherwise - is_msgspec (testobj)
-
Check if the given object is a message spec.
Parameters
- testobj: object to test
Return value:
true if testobj is a message spec, false otherwise - resolve_type (type, package)
-
Resolve the given type.
Parameters
- type: to resolve
- package: to which the type should be resolve relatively
Return value:
the given value if it is either a base type or contains a slash, otherwise returns package/type.