steiner tree (?)

src/steiner_tree.rs

@@ -2,7 +2,8 @@ use {
     crate::{
         morphism::{
             Morphism, MorphismType
-        }, morphism_base::MorphismBase, morphism_path::ShortestPathProblem, TypeID, TypeTerm
+        }, morphism_base::MorphismBase, morphism_path::ShortestPathProblem, TypeID, TypeTerm,
+        MorphismInstance,
     }, std::collections::HashMap
 };
 
@@ -86,10 +87,11 @@ impl PathApproxSteinerTreeSolver {
         }
     }
 
-    pub fn solve<M: Morphism + Clone>(self, morphisms: &MorphismBase<M>) -> Option< SteinerTree > {
-        let mut tree = Vec::<MorphismType>::new();
+    pub fn solve<M: Morphism + Clone + PartialEq>(self, morphisms: &MorphismBase<M>) -> Option< SteinerTree > {
+        let mut edges = Vec::<MorphismType>::new();
 
         for goal in self.leaves {
+            eprintln!("solve steiner tree: find path to goal {:?}", goal);
             // try to find shortest path from root to current leaf
             if let Some(new_path) = ShortestPathProblem::new(
                 morphisms,
@@ -98,6 +100,16 @@ impl PathApproxSteinerTreeSolver {
                     dst_type: goal.clone()
                 }
             ).solve() {
+
+                eprintln!("path to {:?} has len {}", goal.clone(), new_path.len());
+                for morph_inst in new_path {
+                    let t = morph_inst.get_type();
+                    if ! edges.contains(&t) {
+                        eprintln!("add edge {:?}", t);
+                        edges.push(t);
+                    }
+                }
+/*
                 // reduce new path so that it does not collide with any existing path
                 let mut src_type = self.root.clone();
                 let mut new_path_iter = new_path.into_iter().peekable();
@@ -110,6 +122,7 @@ impl PathApproxSteinerTreeSolver {
 
                 for mt in tree.iter() {
                     //assert!( mt.src_type == &src_type );
+
                     if let Some(inst) = new_path_iter.peek() {
                         let t = inst.get_type().dst_type;
                         if &mt.dst_type == &t {
@@ -128,6 +141,7 @@ impl PathApproxSteinerTreeSolver {
                     });
                     src_type = inst.get_type().dst_type;
                 }
+*/
             } else {
                 eprintln!("could not find path\nfrom {:?}\nto {:?}", &self.root, &goal);
                 return None;
@@ -137,7 +151,7 @@ impl PathApproxSteinerTreeSolver {
         Some(SteinerTree {
             weight: 0,
             goals: vec![],
-            edges: tree
+            edges
         })
     }
 }