breaking things up, refactors Problem with vectors...
This commit is contained in:
@@ -7,11 +7,11 @@ use std::clone::Clone;
|
||||
use std::collections::HashMap;
|
||||
|
||||
/// An assignments map of variables
|
||||
pub type Variables<'a, V, K> = HashMap<K, Option<&'a V>>;
|
||||
pub type Variables<'a, V> = Vec<Option<&'a V>>;
|
||||
|
||||
enum Assignment<'a, V, K> {
|
||||
Update(K, &'a V),
|
||||
Clear(K)
|
||||
enum Assignment<'a, V> {
|
||||
Update(usize, &'a V),
|
||||
Clear(usize)
|
||||
}
|
||||
|
||||
/// Collection of references to values owned by a domain.
|
||||
@@ -99,7 +99,7 @@ impl<V: fmt::Debug> fmt::Debug for Domain<V> {
|
||||
}
|
||||
|
||||
|
||||
pub type Constraint<'a,V, K> = fn(&Variables<'a,V, K>) -> bool;
|
||||
pub type Constraint<'a,V> = fn(&Variables<'a,V>) -> bool;
|
||||
|
||||
|
||||
/// Could be more efficient to just use fixed array of options as variables,
|
||||
@@ -108,12 +108,13 @@ pub type Constraint<'a,V, K> = fn(&Variables<'a,V, K>) -> bool;
|
||||
/// It makes sense with an array where indexing is O(1)
|
||||
|
||||
pub struct Problem<'a, V, K> {
|
||||
keys: Vec<K>,
|
||||
/// The initial assignements map
|
||||
variables: Variables<'a, V, K>,
|
||||
variables: Variables<'a, V>,
|
||||
/// Each variable has its associated domain
|
||||
domains: HashMap<K, DomainValues<'a,V>>,
|
||||
domains: Vec<DomainValues<'a,V>>,
|
||||
/// Set of constraints to validate
|
||||
constraints: Vec<Constraint<'a,V,K>>,
|
||||
constraints: Vec<Constraint<'a,V>>,
|
||||
}
|
||||
|
||||
impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
@@ -130,7 +131,7 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
|
||||
/// Returns all possible Updates for next assignements, prepended with
|
||||
/// a Clear to ensure the variable is unset before when leaving the branch.
|
||||
fn _push_updates(&self) -> Option<Vec<Assignment<'a,V, K>>> {
|
||||
fn _push_updates(&self) -> Option<Vec<Assignment<'a,V>>> {
|
||||
// TODO: should be able to inject a choosing strategy
|
||||
if let Some(key) = self._next_assign() {
|
||||
let domain_values = self.domains
|
||||
@@ -142,10 +143,7 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
// TODO: should be able to filter domain values (inference, pertinence)
|
||||
domain_values.iter().for_each(|value| {
|
||||
updates.push(
|
||||
Assignment::Update(
|
||||
key.clone(),
|
||||
*value
|
||||
)
|
||||
Assignment::Update(key, *value)
|
||||
);
|
||||
});
|
||||
Some(updates)
|
||||
@@ -154,11 +152,11 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
}
|
||||
}
|
||||
|
||||
fn _next_assign(&self) -> Option<&K> {
|
||||
self.variables
|
||||
.iter()
|
||||
.find_map(|(key, val)| {
|
||||
if val.is_none() { Some(key) }
|
||||
fn _next_assign(&self) -> Option<usize> {
|
||||
self.variables.iter()
|
||||
.enumerate()
|
||||
.find_map(|(idx, val)| {
|
||||
if val.is_none() { Some(idx) }
|
||||
else { None }
|
||||
})
|
||||
}
|
||||
@@ -172,12 +170,12 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
}
|
||||
|
||||
/// Returns all complete solutions, after visiting all possible outcomes using a stack (DFS).
|
||||
pub fn solve_all(&mut self) -> Vec<Variables<'a,V,K>>
|
||||
pub fn solve_all(&mut self) -> Vec<Variables<'a,V>>
|
||||
where V: Clone + fmt::Debug,
|
||||
K: Clone + fmt::Debug,
|
||||
{
|
||||
let mut solutions: Vec<Variables<V, K>> = vec![];
|
||||
let mut stack: Vec<Assignment<'a, V, K>> = vec![];
|
||||
let mut solutions: Vec<Variables<V>> = vec![];
|
||||
let mut stack: Vec<Assignment<'a, V>> = vec![];
|
||||
if let Some(mut init_updates) = self._push_updates() {
|
||||
stack.append(&mut init_updates);
|
||||
} else {
|
||||
@@ -189,9 +187,9 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
let node = stack.pop();
|
||||
if node.is_none() { break; };
|
||||
match node.unwrap() {
|
||||
Assignment::Update(key, val) => {
|
||||
Assignment::Update(idx, val) => {
|
||||
// Assign the variable and open new branches, if any.
|
||||
*self.variables.get_mut(&key).unwrap() = Some(val);
|
||||
self.variables[idx] = Some(val);
|
||||
// TODO: handle case of empty domain.values
|
||||
if let Some(mut nodes) = self._push_updates() {
|
||||
stack.append(&mut nodes);
|
||||
@@ -202,20 +200,20 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
};
|
||||
};
|
||||
},
|
||||
Assignment::Clear(key) => {
|
||||
Assignment::Clear(idx) => {
|
||||
// We are closing this branch, unset the variable
|
||||
*self.variables.get_mut(&key).unwrap() = None;
|
||||
self.variables[idx] = None;
|
||||
},
|
||||
};
|
||||
};
|
||||
solutions
|
||||
}
|
||||
|
||||
pub fn solve_one(&mut self) -> Option<Variables<'a,V,K>>
|
||||
pub fn solve_one(&mut self) -> Option<Variables<'a,V>>
|
||||
where V: Clone + fmt::Debug,
|
||||
K: Clone + fmt::Debug,
|
||||
{
|
||||
let mut stack: Vec<Assignment<'a, V, K>> = vec![];
|
||||
let mut stack: Vec<Assignment<'a, V>> = vec![];
|
||||
if let Some(mut init_updates) = self._push_updates() {
|
||||
stack.append(&mut init_updates);
|
||||
} else {
|
||||
@@ -228,9 +226,9 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
return None;
|
||||
};
|
||||
match node.unwrap() {
|
||||
Assignment::Update(key, val) => {
|
||||
Assignment::Update(idx, val) => {
|
||||
// Assign the variable and open new branches, if any.
|
||||
*self.variables.get_mut(&key).unwrap() = Some(val);
|
||||
self.variables[idx] = Some(val);
|
||||
// TODO: handle case of empty domain.values
|
||||
if let Some(mut nodes) = self._push_updates() {
|
||||
stack.append(&mut nodes);
|
||||
@@ -241,9 +239,9 @@ impl<'a, V, K: Eq + Hash + Clone> Problem<'a, V, K> {
|
||||
};
|
||||
};
|
||||
},
|
||||
Assignment::Clear(key) => {
|
||||
Assignment::Clear(idx) => {
|
||||
// We are closing this branch, unset the variable
|
||||
*self.variables.get_mut(&key).unwrap() = None;
|
||||
self.variables[idx] = None;
|
||||
},
|
||||
};
|
||||
}
|
||||
@@ -256,20 +254,22 @@ impl<'a, V, K: Eq + Hash + Clone> ProblemBuilder<'a, V, K> {
|
||||
fn new() -> ProblemBuilder<'a, V, K> {
|
||||
ProblemBuilder(
|
||||
Problem{
|
||||
keys: Vec::new(),
|
||||
variables: Variables::new(),
|
||||
domains: HashMap::new(),
|
||||
domains: Vec::new(),
|
||||
constraints: Vec::new(),
|
||||
})
|
||||
}
|
||||
|
||||
pub fn add_variable(mut self, name: K, domain: Vec<&'a V>, value: Option<&'a V>) -> Self
|
||||
{
|
||||
self.0.variables.insert(name.clone(), value);
|
||||
self.0.domains.insert(name, domain);
|
||||
self.0.keys.push(name);
|
||||
self.0.variables.push(value);
|
||||
self.0.domains.push(domain);
|
||||
self
|
||||
}
|
||||
|
||||
pub fn add_constraint(mut self, cons: Constraint<'a,V, K>) -> Self {
|
||||
pub fn add_constraint(mut self, cons: Constraint<'a,V>) -> Self {
|
||||
self.0.constraints.push(cons);
|
||||
self
|
||||
}
|
||||
@@ -289,15 +289,15 @@ mod tests {
|
||||
let mut problem: Problem<_, _> = Problem::build()
|
||||
.add_variable(String::from("Left"), domain.all(), None)
|
||||
.add_variable(String::from("Right"), domain.all(), None)
|
||||
.add_constraint(|assign: &Variables<i32, _>| {
|
||||
assign.get("Left").unwrap() == assign.get("Right").unwrap()
|
||||
.add_constraint(|assign: &Variables<i32>| {
|
||||
assign[0] == assign[1]
|
||||
})
|
||||
.finish();
|
||||
|
||||
let solutions: Vec<Variables<i32, _>> = vec![
|
||||
[("Left".to_string(), Some(&3)), ("Right".to_string(), Some(&3)),].iter().cloned().collect(),
|
||||
[("Left".to_string(), Some(&2)), ("Right".to_string(), Some(&2)),].iter().cloned().collect(),
|
||||
[("Left".to_string(), Some(&1)), ("Right".to_string(), Some(&1)),].iter().cloned().collect(),
|
||||
let solutions: Vec<Variables<i32>> = vec![
|
||||
[Some(&3), Some(&3)].iter().cloned().collect(),
|
||||
[Some(&2), Some(&2)].iter().cloned().collect(),
|
||||
[Some(&1), Some(&1)].iter().cloned().collect(),
|
||||
];
|
||||
|
||||
assert_eq!(problem.solve_all(), solutions);
|
||||
@@ -310,13 +310,13 @@ mod tests {
|
||||
let mut problem: Problem<_, _> = Problem::build()
|
||||
.add_variable("Left".to_string(), domain.all(), None)
|
||||
.add_variable("Right".to_string(), domain.all(), Some(&2))
|
||||
.add_constraint( |assign: &Variables<i32, _>| {
|
||||
assign.get("Left").unwrap() == assign.get("Right").unwrap()
|
||||
.add_constraint( |assign: &Variables<i32>| {
|
||||
assign[0] == assign[1]
|
||||
})
|
||||
.finish();
|
||||
|
||||
let solutions: Vec<Variables<i32, _>> = vec![
|
||||
[("Left".to_string(), Some(&2)), ("Right".to_string(), Some(&2)),].iter().cloned().collect(),
|
||||
let solutions: Vec<Variables<i32>> = vec![
|
||||
[Some(&2), Some(&2)].iter().cloned().collect(),
|
||||
];
|
||||
|
||||
assert_eq!(problem.solve_all(), solutions);
|
||||
|
||||
Reference in New Issue
Block a user