Builder first iteration: bool constraints

examples/simple_sat_program.rs

@@ -1,40 +1,19 @@
-use cp_sat::proto::{
-    constraint_proto::Constraint, AllDifferentConstraintProto, ConstraintProto, CpModelProto,
-    IntegerVariableProto,
-};
-
 fn main() {
-    let model = CpModelProto {
-        variables: vec![
-            IntegerVariableProto {
-                name: "x".into(),
-                domain: vec![0, 2],
-            },
-            IntegerVariableProto {
-                name: "y".into(),
-                domain: vec![0, 2],
-            },
-            IntegerVariableProto {
-                name: "z".into(),
-                domain: vec![0, 2],
-            },
-        ],
-        constraints: vec![ConstraintProto {
-            constraint: Some(Constraint::AllDiff(AllDifferentConstraintProto {
-                vars: vec![0, 1, 2],
-            })),
-            ..Default::default()
-        }],
-        ..Default::default()
-    };
+    let mut model = cp_sat::builder::CpModelBuilder::default();
+    let x = model.new_int_var_with_name([(0, 2)], "x");
+    let y = model.new_int_var_with_name([(0, 2)], "y");
+    let z = model.new_int_var_with_name([(0, 2)], "z");
+    model.add_all_different([x, y, z]);
     println!("{:#?}", model);
-
-    println!("model stats: {}", cp_sat::cp_model_stats(&model));
-
-    let response = cp_sat::solve(&model);
+    println!("model stats: {}", model.stats());
+    let response = model.solve();
     println!("{:#?}", response);
     println!(
         "response stats: {}",
         cp_sat::cp_solver_response_stats(&response, false)
     );
+    assert_eq!(response.status(), cp_sat::proto::CpSolverStatus::Optimal);
+    assert!(x.solution_value(&response) != y.solution_value(&response));
+    assert!(x.solution_value(&response) != z.solution_value(&response));
+    assert!(y.solution_value(&response) != z.solution_value(&response));
 }

src/builder.rs

@@ -0,0 +1,173 @@
+use crate::proto;
+
+#[derive(Default, Debug)]
+pub struct CpModelBuilder {
+    proto: proto::CpModelProto,
+}
+
+impl CpModelBuilder {
+    pub fn proto(&self) -> &proto::CpModelProto {
+        &self.proto
+    }
+    pub fn new_bool_var(&mut self) -> BoolVar {
+        self.new_bool_var_with_name("")
+    }
+    pub fn new_bool_var_with_name(&mut self, name: impl Into<String>) -> BoolVar {
+        let index = self.proto.variables.len() as i32;
+        self.proto.variables.push(proto::IntegerVariableProto {
+            name: name.into(),
+            domain: vec![0, 1],
+        });
+        BoolVar(index)
+    }
+    pub fn new_int_var(&mut self, domain: impl IntoIterator<Item = (i64, i64)>) -> IntVar {
+        self.new_int_var_with_name(domain, "")
+    }
+    pub fn new_int_var_with_name(
+        &mut self,
+        domain: impl IntoIterator<Item = (i64, i64)>,
+        name: impl Into<String>,
+    ) -> IntVar {
+        let index = self.proto.variables.len() as i32;
+        self.proto.variables.push(proto::IntegerVariableProto {
+            name: name.into(),
+            domain: domain.into_iter().flat_map(|(b, e)| [b, e]).collect(),
+        });
+        IntVar(index)
+    }
+    pub fn var_name(&self, var: impl Into<IntVar>) -> &str {
+        &self.proto.variables[var.into().0 as usize].name
+    }
+    pub fn set_var_name(&mut self, var: impl Into<IntVar>, name: &str) {
+        self.proto.variables[var.into().0 as usize].name = name.into();
+    }
+
+    pub fn add_or(&mut self, vars: impl IntoIterator<Item = BoolVar>) -> Constraint {
+        let index = self.proto.constraints.len();
+        self.proto.constraints.push(proto::ConstraintProto {
+            constraint: Some(proto::constraint_proto::Constraint::BoolOr(
+                proto::BoolArgumentProto {
+                    literals: vars.into_iter().map(|v| v.0).collect(),
+                },
+            )),
+            ..Default::default()
+        });
+        Constraint(index)
+    }
+    pub fn add_and(&mut self, vars: impl IntoIterator<Item = BoolVar>) -> Constraint {
+        let index = self.proto.constraints.len();
+        self.proto.constraints.push(proto::ConstraintProto {
+            constraint: Some(proto::constraint_proto::Constraint::BoolAnd(
+                proto::BoolArgumentProto {
+                    literals: vars.into_iter().map(|v| v.0).collect(),
+                },
+            )),
+            ..Default::default()
+        });
+        Constraint(index)
+    }
+    pub fn add_at_most_one(&mut self, vars: impl IntoIterator<Item = BoolVar>) -> Constraint {
+        let index = self.proto.constraints.len();
+        self.proto.constraints.push(proto::ConstraintProto {
+            constraint: Some(proto::constraint_proto::Constraint::AtMostOne(
+                proto::BoolArgumentProto {
+                    literals: vars.into_iter().map(|v| v.0).collect(),
+                },
+            )),
+            ..Default::default()
+        });
+        Constraint(index)
+    }
+    pub fn add_exactly_one(&mut self, vars: impl IntoIterator<Item = BoolVar>) -> Constraint {
+        let index = self.proto.constraints.len();
+        self.proto.constraints.push(proto::ConstraintProto {
+            constraint: Some(proto::constraint_proto::Constraint::ExactlyOne(
+                proto::BoolArgumentProto {
+                    literals: vars.into_iter().map(|v| v.0).collect(),
+                },
+            )),
+            ..Default::default()
+        });
+        Constraint(index)
+    }
+    pub fn add_xor(&mut self, vars: impl IntoIterator<Item = BoolVar>) -> Constraint {
+        let index = self.proto.constraints.len();
+        self.proto.constraints.push(proto::ConstraintProto {
+            constraint: Some(proto::constraint_proto::Constraint::BoolXor(
+                proto::BoolArgumentProto {
+                    literals: vars.into_iter().map(|v| v.0).collect(),
+                },
+            )),
+            ..Default::default()
+        });
+        Constraint(index)
+    }
+    pub fn add_all_different(&mut self, vars: impl IntoIterator<Item = IntVar>) -> Constraint {
+        let index = self.proto.constraints.len();
+        self.proto.constraints.push(proto::ConstraintProto {
+            constraint: Some(proto::constraint_proto::Constraint::AllDiff(
+                proto::AllDifferentConstraintProto {
+                    vars: vars.into_iter().map(|v| v.0).collect(),
+                },
+            )),
+            ..Default::default()
+        });
+        Constraint(index)
+    }
+
+    pub fn stats(&self) -> String {
+        crate::cp_model_stats(self.proto())
+    }
+    pub fn solve(&self) -> proto::CpSolverResponse {
+        crate::solve(self.proto())
+    }
+}
+
+#[derive(Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct BoolVar(i32);
+impl BoolVar {
+    pub fn solution_value(self, response: &proto::CpSolverResponse) -> bool {
+        if self.0 < 0 {
+            use std::ops::Not;
+            !self.not().solution_value(response)
+        } else {
+            response.solution[self.0 as usize] != 0
+        }
+    }
+}
+impl std::ops::Not for BoolVar {
+    type Output = Self;
+    fn not(self) -> Self {
+        Self(-self.0 - 1)
+    }
+}
+impl std::fmt::Debug for BoolVar {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> Result<(), std::fmt::Error> {
+        if self.0 < 0 {
+            write!(f, "Not({:?})", !*self)
+        } else {
+            write!(f, "BoolVar({})", self.0)
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct IntVar(i32);
+impl From<BoolVar> for IntVar {
+    fn from(bool_var: BoolVar) -> IntVar {
+        IntVar(bool_var.0)
+    }
+}
+impl IntVar {
+    pub fn solution_value(self, response: &proto::CpSolverResponse) -> i64 {
+        if self.0 < 0 {
+            use std::ops::Not;
+            1 - IntVar::from(BoolVar(self.0).not()).solution_value(response)
+        } else {
+            response.solution[self.0 as usize]
+        }
+    }
+}
+
+#[derive(Copy, Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct Constraint(usize);

src/lib.rs

@@ -5,6 +5,7 @@ use std::ffi::CStr;
 pub mod proto {
     include!(concat!(env!("OUT_DIR"), "/operations_research.sat.rs"));
 }
+pub mod builder;
 
 extern "C" {
     fn cp_sat_wrapper_solve(

tests/bool_cst.rs

@@ -0,0 +1,94 @@
+use cp_sat::builder::CpModelBuilder;
+use cp_sat::proto::CpSolverStatus;
+
+#[test]
+fn or() {
+    let mut model = CpModelBuilder::default();
+    let x = model.new_bool_var();
+    let y = model.new_bool_var();
+    model.add_or([x, y]);
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Optimal);
+    assert!(x.solution_value(&response) || y.solution_value(&response));
+}
+
+#[test]
+fn and() {
+    let mut model = CpModelBuilder::default();
+    let x = model.new_bool_var();
+    let y = model.new_bool_var();
+    model.add_and([x, y]);
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Optimal);
+    assert!(x.solution_value(&response));
+    assert!(y.solution_value(&response));
+}
+
+#[test]
+fn at_most_one() {
+    let mut model = CpModelBuilder::default();
+    let vars: Vec<_> = (0..10).map(|_| model.new_bool_var()).collect();
+    model.add_at_most_one(vars.iter().copied());
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Optimal);
+    assert!(
+        vars.iter()
+            .map(|v| v.solution_value(&response) as u32)
+            .sum::<u32>()
+            <= 1
+    );
+}
+
+#[test]
+fn exactly_one() {
+    let mut model = CpModelBuilder::default();
+    let vars: Vec<_> = (0..10).map(|_| model.new_bool_var()).collect();
+    model.add_exactly_one(vars.iter().copied());
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Optimal);
+    assert!(
+        vars.iter()
+            .map(|v| v.solution_value(&response) as u32)
+            .sum::<u32>()
+            == 1
+    );
+}
+
+#[test]
+fn xor() {
+    let mut model = CpModelBuilder::default();
+    let vars: Vec<_> = (0..10).map(|_| model.new_bool_var()).collect();
+    model.add_xor(vars.iter().copied());
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Optimal);
+    assert!(
+        vars.iter()
+            .map(|v| v.solution_value(&response) as u32)
+            .sum::<u32>()
+            % 2
+            == 1
+    );
+}
+
+#[test]
+fn not_infeasible() {
+    let mut model = CpModelBuilder::default();
+    let x = model.new_bool_var();
+    model.add_and([x, !x]);
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Infeasible);
+}
+
+#[test]
+fn not_feasible() {
+    let mut model = CpModelBuilder::default();
+    let x = model.new_bool_var();
+    let y = model.new_bool_var();
+    model.add_and([x, !y]);
+    let response = model.solve();
+    assert_eq!(response.status(), CpSolverStatus::Optimal);
+    assert!(x.solution_value(&response));
+    assert!(!(!x).solution_value(&response));
+    assert!(!y.solution_value(&response));
+    assert!((!y).solution_value(&response));
+}