add tutorial

examples/conformance/woods.py

@@ -198,7 +198,3 @@ if yes_no("Print PlantUML?"):
     print("==================================")
     print(make_url(uml))
     print("==================================")
-    print("Go to either:")
-    print("  ▸ https://www.plantuml.com/plantuml/uml")
-    print("  ▸ https://mstro.duckdns.org/plantuml/uml")
-    print("and paste the above string.")

tutorial/03_api.py

@@ -0,0 +1,72 @@
+# We reuse our (meta-)model from the previous tutorial. For this tutorial, it doesn't really matter what the models look like.
+
+mm_cs = """
+    MyAbstractClass:Class {
+        abstract = True;
+    }
+
+    MyConcreteClass:Class
+
+    :Inheritance (MyConcreteClass -> MyAbstractClass)
+
+    Z:Class
+
+    myZ:Association (MyAbstractClass -> Z) {
+        target_lower_cardinality = 1;
+    }
+
+"""
+
+m_cs = """
+    cc:MyConcreteClass
+    z:Z
+    :myZ (cc -> z)
+"""
+
+
+# We parse everything:
+
+from state.devstate import DevState
+from bootstrap.scd import bootstrap_scd
+from util import loader
+
+state = DevState()
+mmm = bootstrap_scd(state)
+mm = loader.parse_and_check(state, mm_cs, mmm, "mm")
+m = loader.parse_and_check(state, m_cs, mm, "m")
+
+
+# We can query the model via an API called ODAPI (Object Diagram API):
+
+from api.od import ODAPI
+
+odapi = ODAPI(state, m, mm)
+
+ls = odapi.get_all_instances("MyAbstractClass", include_subtypes=True)
+
+print("result of get_all_instances:")
+print(ls)
+
+# Observing the output above, we see that we got a list of tuples (object_name, UUID).
+# We can also modify the model via the same API:
+
+(cc_name, cc_id) = ls[0]
+z2 = odapi.create_object("z2", "Z")
+odapi.create_link("lnk", "myZ", cc_id, z2)
+
+# And we can observe the modified model:
+
+from concrete_syntax.textual_od.renderer import render_od
+from concrete_syntax.common import indent
+
+print()
+print("the modified model:")
+print(indent(render_od(state, m, mm, hide_names=False), 2))
+
+# BTW, notice that the anonymous link of type 'myZ' from the original model was automatically given a unique name (starting with two underscores).
+
+# The full ODAPI is documented on page 6 of this PDF:
+#   http://msdl.uantwerpen.be/people/hv/teaching/MSBDesign/202425/assignments/assignment6.pdf
+
+
+# On to the next tutorial...