Some new methods

Later versions of the GELLO editor improve the writability of code when getting a casted value from an observation, and also when as part of that process applying an existence test.

Methods like .asCD() replace .value.oclAsType(CD); and .oclIfUndefined()  replaces extra lines of code. The .oclIfUndefined() is an example of null coalescing. and is particularly useful when using GELLO within archetypes. 

For example this:

Let tumourSite: String= If template.Examples.Tumour_site
                                     .value.oclAsType(CD).oclIsDefined() 
                                        then  
                             template.Examples.Tumour_site
                                     .value.oclAsType(CD).displayName.value
                     else '' endif 

can be rewritten as this:

Let tumourSite: String= template.Examples.Tumour_site.asCD().displayName.value.oclIfUndefined('')

Most types have these methods now, ie asBoolean(), asString() ..