code cleanup

planner/src/solver.rs

@@ -14,12 +14,14 @@ enum Assignment<'a, V, K> {
     Clear(K)
 }
 
-
+/// Collection of references to values owned by a domain.
 pub type DomainValues<'a, V> = Vec<&'a V>;
-/// The domain of values that can be assigned to variables
+
+/// The domain of values that can be assigned to a variable.
+/// The values are owned by the instance.
 #[derive(Clone)]
 pub struct Domain<V> {
-    pub values: Vec<V>
+    values: Vec<V>
 }
 
 impl<V> Domain<V> {
@@ -27,11 +29,21 @@ impl<V> Domain<V> {
         Domain { values }
     }
 
-    /// Returns all values of a Domain instance
+    /// Returns references to all values of this instance
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate planner;
+    /// # use planner::solver::Domain;
+    /// let domain = Domain::new(vec!["a", "b", "c"]);
+    /// assert_eq!(domain.all(), vec![&"a", &"b", &"c"]);
+    /// ```
     pub fn all(&self) -> DomainValues<V> {
         self.values.iter().collect()
     }
-    /// Returns a Filter filter applied to inner values
+    /// Returns a collection of references to a filtered
+    /// subset of this domain.
     ///
     /// # Examples
     ///
@@ -45,13 +57,39 @@ impl<V> Domain<V> {
     /// assert_eq!(domain.filter(even), vec![&2]);
     /// assert_eq!(domain.filter(|i: &i32| i % 2 == 1), vec![&1,&3]);
     /// ```
-    pub fn filter(&self, filter_func: fn(&V) -> bool) -> DomainValues<V> {
+    pub fn filter<F>(&self, filter_func: F) -> DomainValues<V>
+        where F: Fn(&V) -> bool
+    {
         self.values
             .iter()
             .filter(|v: &&V| filter_func(*v))
             .collect()
     }
 
+    /// Wrapper for `find`, returns a optionnal reference
+    /// to the first found value of this domain.
+    ///
+    /// # Examples
+    ///
+    /// ```
+    /// # extern crate planner;
+    /// # use planner::solver::Domain;
+    /// let domain = Domain::new(vec![1,2,3]);
+    /// fn even(i: &i32) -> bool {
+    ///     *i == 2
+    /// };
+    /// assert_eq!(domain.find(even), Some(&2));
+    /// assert_eq!(domain.find(|i: &i32| i % 2 == 1), Some(&1));
+    /// assert_eq!(domain.find(|i| *i == 4), None);
+    /// ```
+    pub fn find<F>(&self, getter_func: F) -> Option<&V>
+        where F: Fn(&V) -> bool
+    {
+        self.values
+            .iter()
+            .find(|v: &&V| getter_func(*v))
+    }
+
 }
 
 impl<V: fmt::Debug> fmt::Debug for Domain<V> {
@@ -63,6 +101,12 @@ impl<V: fmt::Debug> fmt::Debug for Domain<V> {
 
 pub type Constraint<'a,V, K> = fn(&Variables<'a,V, K>) -> bool;
 
+
+/// Could be more efficient to just use fixed array of options as variables,
+/// using a helper to bind Keys to Index in this array.
+/// Domains could be a similar array of DomainValues.
+/// It makes sense with an array where indexing is O(1)
+
 pub struct Problem<'a, V, K> {
     /// The initial assignements map
     variables: Variables<'a, V, K>,
@@ -72,7 +116,7 @@ pub struct Problem<'a, V, K> {
     constraints: Vec<Constraint<'a,V,K>>,
 }
 
-impl<'a,V, K: Eq + Hash + Clone> Problem<'a, V, K> {
+impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
 
     pub fn build() -> ProblemBuilder<'a,V, K> {
         ProblemBuilder::new()
@@ -88,22 +132,37 @@ impl<'a,V, K: Eq + Hash + Clone> Problem<'a, V, K> {
     /// a Clear to ensure the variable is unset before when leaving the branch.
     fn _push_updates(&self) -> Option<Vec<Assignment<'a,V, K>>> {
         // TODO: should be able to inject a choosing strategy
-        if let Some((key,_)) = self.variables.iter().find(|(_, val)| val.is_none()) {
+        if let Some(key) = self._next_assign() {
-            let domain_values = self.domains.get(key).expect("No domain for variable !");
+            let domain_values = self.domains
+                                    .get(key)
+                                    .expect("No domain for variable !");
+            assert!(!domain_values.is_empty());
             // Push a clear assignment first, just before going up the stack.
             let mut updates = vec![Assignment::Clear(key.clone())];
-
-            if domain_values.is_empty() { panic!("No value in domain !"); }
             // TODO: should be able to filter domain values (inference, pertinence)
-            for value in domain_values.into_iter() {
+            domain_values.iter().for_each(|value| {
-                updates.push(Assignment::Update(key.clone(), *value));
+                updates.push(
-            }
+                    Assignment::Update(
+                        key.clone(),
+                        *value
+                    )
+                );
+            });
             Some(updates)
         } else { // End of assignements
             None
         }
     }
 
+    fn _next_assign(&self) -> Option<&K> {
+        self.variables
+            .iter()
+            .find_map(|(key, val)| {
+                    if val.is_none() { Some(key) }
+                    else { None }
+            })
+    }
+
     /// Checks that the current assignments doesn't violate any constraint
     fn _is_valid(&self) -> bool {
         for validator in self.constraints.iter() {

web/src/main.rs

@@ -151,7 +151,8 @@ mod api {
                         }
                     });
             let ini = if let Some(id) = initial_id {
-                let new_ini = domain.values.iter().find(|r| r.id == id);
+                // Not working because we're capturing `id`
+                let new_ini = domain.find(|r| {r.id == id});
                 println!("Overrided {:?}", new_ini);
                 new_ini
             } else {