+#
+# The loader takes care of looking for module and projects in the file system, and the associated case of errors.
+# The loading requires several steps:
+#
+# Identify: create an empty model entity associated to a name or a file path.
+# Identification is used for instance when names are given in the command line.
+# See `identify_module` and `identify_group`.
+#
+# Scan: visit directories and identify their contents.
+# Scanning is done to enable the searching of modules in projects.
+# See `scan_group` and `scan_full`.
+#
+# Parse: load the AST and associate it with the model entity.
+# See `MModule::parse`.
+#
+# Import: means recursively load modules imported by a module.
+# See `build_module_importation`.
+#
+# Load: means doing the full sequence: identify, parse and import.
+# See `ModelBuilder::parse`, `ModelBuilder::parse_full`, `MModule::load` `ModelBuilder::load_module.