Fix typo, add getGradient, add package.xml to build in catkin workspaces

[wxmerkt]

• Fixes typos including in method names
• Add getGradient to return the last gradient
• Adds a package.xml to build in catkin/colcon workspaces

[traversaro]

Some comments, thanks in any case!

[traversaro]

Again, not blocking the merge but I am tipically afraid of multiple places in which the version is defined. @GiulioRomualdi note that this may need to be updated for every new release, if necessary we can setup tooling to do this automatically.

[traversaro]

Otherwise we can modify the CMake to read the version from package.xml, for example dart is doing it via:

# Extract version numbers from package.xml
file(READ package.xml PACKAGE_XML)
string(REGEX MATCH "<version>[0-9]+\\.[0-9]+\\.[0-9]+</version>" DIRTY_VERSION_STRING ${PACKAGE_XML})
string(REGEX REPLACE "^<version>([0-9]+)\\.([0-9]+)\\.([0-9]+)</version>$" "\\1" DART_MAJOR_VERSION "${DIRTY_VERSION_STRING}")
string(REGEX REPLACE "^<version>([0-9]+)\\.([0-9]+)\\.([0-9]+)</version>$" "\\2" DART_MINOR_VERSION "${DIRTY_VERSION_STRING}")
string(REGEX REPLACE "^<version>([0-9]+)\\.([0-9]+)\\.([0-9]+)</version>$" "\\3" DART_PATCH_VERSION "${DIRTY_VERSION_STRING}")
set(DART_VERSION "${DART_MAJOR_VERSION}.${DART_MINOR_VERSION}.${DART_PATCH_VERSION}")

see https://github.com/dartsim/dart/blob/f07186fbdb4e89e5340abb9718d02715bb315922/CMakeLists.txt#L62 .

But perhaps this brings more complexity that it is worth.

[wxmerkt]

Would you like me to add this to this PR or is this a comment to keep track of for future reference?

[GiulioRomualdi]

Hi @wxmerkt, it would be nice if you could add this modification. In this case, I would also like to ask you to modify the version in the package.xml to 0.6.4.100. We will release 0.7.0 soon

[wxmerkt]

I don't think package.xml or semver supports a third period (beyond patch release). How about 0.6.5?

[wxmerkt]

I've made the requested updates. Note that the version convention won't allow 0.6.4.100. It has to be major-minor-patch. Hence, I've used 0.6.4.

[GiulioRomualdi]

Hi @wxmerkt, thank you very much for the contribution! I've added just a comment regarding the deprecation of the methods you modified.

[GiulioRomualdi]

Thank you very much @wxmerkt for the effort, I am going to merge it 😃