build repr tree

lib-nested-core/src/repr_tree/context.rs

@@ -120,6 +120,32 @@ impl Context {
         }    
     }
 
+    pub fn build_repr_tree(
+        &self,
+        rt: &Arc<RwLock<ReprTree>>,
+        root: TypeTerm,
+        leaves: Vec< TypeTerm >
+    ) {
+        let mut st_problem = laddertypes::steiner_tree::PathApproxSteinerTreeSolver::new(
+            root,
+            leaves
+        );
+
+        if let Some( steiner_tree ) = st_problem.solve( &self.morphisms ) {
+            for morphism_type in steiner_tree.into_edges() {
+                eprintln!("--> apply morph to {}", self.type_term_to_str(&morphism_type.dst_type));
+                if let Some(( morphism, mut τ, σ )) =
+                    self.morphisms.find_morphism_with_subtyping( &morphism_type )
+                {
+                    let mut rt = rt.descend( τ ).expect("descend src repr");
+                    (morphism.setup_projection)( &mut rt, &σ );
+                }
+            }
+        } else {
+            eprintln!("could not find steiner tree to build the requested repr tree");
+        }
+    }
+
     pub fn make_repr(ctx: &Arc<RwLock<Self>>, t: &TypeTerm) -> Arc<RwLock<ReprTree>> {
         let rt = Arc::new(RwLock::new(ReprTree::new( TypeTerm::unit() )));
         ctx.read().unwrap().apply_morphism( &rt, &MorphismType{ src_type: TypeTerm::unit(), dst_type: t.clone() } );