Crate minion_rs

This crate provides low level Rust bindings to the Minion constraint solver.

Examples

Consider the following Minion problem:

MINION 3
**VARIABLES**
DISCRETE x #
{1..3}
DISCRETE y #
{2..4}
DISCRETE z #
{1..5}
**SEARCH**
PRINT[[x],[y],[z]]
VARORDER STATIC [x, y, z]
**CONSTRAINTS**
sumleq([x,y,z],4)
ineq(x, y, -1)
**EOF**

This can be solved in Rust like so:

use minion_rs::ast::*;
use minion_rs::run_minion;
use std::collections::HashMap;
use std::sync::Mutex;

// Get solutions out of Minion.
// See the documentation for Callback for details.

static ALL_SOLUTIONS: Mutex<Vec<HashMap<VarName,Constant>>>  = Mutex::new(vec![]);

fn callback(solutions: HashMap<VarName,Constant>) -> bool {
    let mut guard = ALL_SOLUTIONS.lock().unwrap();
    guard.push(solutions);
    true
}

// Build and run the model.
let mut model = Model::new();
model
    .named_variables
    .add_var("x".to_owned(), VarDomain::Bound(1, 3));
model
    .named_variables
    .add_var("y".to_owned(), VarDomain::Bound(2, 4));
model
    .named_variables
    .add_var("z".to_owned(), VarDomain::Bound(1, 5));

let leq = Constraint::SumLeq(
    vec![
        Var::NameRef("x".to_owned()),
        Var::NameRef("y".to_owned()),
        Var::NameRef("z".to_owned()),
    ],
    Var::ConstantAsVar(4),
);

let geq = Constraint::SumGeq(
    vec![
        Var::NameRef("x".to_owned()),
        Var::NameRef("y".to_owned()),
        Var::NameRef("z".to_owned()),
    ],
    Var::ConstantAsVar(4),
);

let ineq = Constraint::Ineq(
    Var::NameRef("x".to_owned()),
    Var::NameRef("y".to_owned()),
    Constant::Integer(-1),
);

model.constraints.push(leq);
model.constraints.push(geq);
model.constraints.push(ineq);

let res = run_minion(model, callback);
res.expect("Error occurred");

// Get solutions
let guard = ALL_SOLUTIONS.lock().unwrap();
let solution_set_1 = &(guard.get(0).unwrap());

let x1 = solution_set_1.get("x").unwrap();
let y1 = solution_set_1.get("y").unwrap();
let z1 = solution_set_1.get("z").unwrap();

assert_eq!(guard.len(),1);
assert_eq!(*x1,Constant::Integer(1));
assert_eq!(*y1,Constant::Integer(2));
assert_eq!(*z1,Constant::Integer(1));

PRINT and VARORDER

These bindings have no replacement for Minion’s PRINT and VARORDER statements - any variable given to the model that does not have a constant value is considered a search variable. Solutions are returned through the callback function as a HashMap.

Modules

• ast
  Types used for representing Minion models in Rust.
• error
  Error types.

Functions

• get_from_table
  Gets a given value from Minion’s TableOut (where it stores run statistics).
• run_minion
  Run Minion on the given Model.

Type Aliases

• Callback
  The callback function used to capture results from Minion as they are generated.