Add doc

Author: jecisc

README.md

@@ -67,6 +67,10 @@ The best documentation to read about this project is located in Pharo Tree Sitte
 
 You can find the documentation on some analysis possible here: [Analysis documentation](resources/doc/analysis.md).
 
+You can find the documentation on exporting models with their derived properties (used by the Profile project) here: [Profile documentation](resources/doc/profile.md).
+
+The export and import of a model are covered by parametric tests: the tests run both on the imported model and on the model exported and re-imported.
+
 
 ## Control flow graph
 

resources/doc/profile.md

@@ -0,0 +1,34 @@
+# Profile documentation
+
+This document describes the tools provided by the `FAST-Python-ExtraTools` package. These tools are used by the Profile project and are **not loaded by default**: to load them, load the `Profile` group of the baseline.
+
+```smalltalk
+Metacello new
+	githubUser: 'moosetechnology' project: 'FAST-Python' commitish: 'main' path: 'src';
+	baseline: 'FASTPython';
+	load: 'Profile'
+```
+
+## Exporting a model with its derived properties
+
+The `FMModelExporterWithDerived` is a special exporter that, contrary to the normal exporter, also exports the derived properties of the entities. This is useful to provide a model to people not using Moose.
+
+To export a model with its derived properties, send `#exportAsJSONWithDerived` to the model:
+
+```smalltalk
+model exportAsJSONWithDerived
+```
+
+> Warning: this export is slower than a normal export because it computes all the caches of the model. Moreover, if a property fails to be computed, it is ignored and not exported.
+
+### Excluding some properties
+
+Some properties can be excluded from the export by giving a blacklist to `#exportAsJSONWithDerivedBlacklist:`. The blacklist should contain the compiled method names of the properties to exclude, in the form `Class>>#selector`:
+
+```smalltalk
+model exportAsJSONWithDerivedBlacklist: #('TEntityMetaLevelDependency>>#isDead' 'TEntityMetaLevelDependency>>#fanIn' 'TEntityMetaLevelDependency>>#fanOut' 'TEntityMetaLevelDependency>>#numberOfDeadChildren' 'TEntityMetaLevelDependency>>#numberOfExternalClients' 'TEntityMetaLevelDependency>>#numberOfExternalProviders' 'TEntityMetaLevelDependency>>#numberOfInternalProviders' 'TEntityMetaLevelDependency>>#numberOfInternalClients')
+```
+
+## Unique identifier
+
+The package adds a `#uniqueIdentifier` property to all entities. This property is a UUID, generated the first time it is accessed and then cached. It is used because the Moose ID is not fixed: it can change between two imports of the same model, so the Profile project needs a stable identifier for its entities.