Merge pull request #106 from Kieranoski702/main

Issues with creating XYZ problem in cpp

solvers/chuffed/build.rs

@@ -81,6 +81,9 @@ fn bind() {
         .allowlist_function("p_setcallback")
         .allowlist_function("p_print")
         .allowlist_function("branch_IntVar")
+        .allowlist_function("new_xyz_problem")
+        .allowlist_function("solve_xyz")
+        .allowlist_function("int_plus")
         .clang_arg(format!("-I{}/build", out_dir))
         .clang_arg("-Ivendor")
         .clang_arg(r"--std=gnu++11")

solvers/chuffed/src/lib.rs

@@ -5,8 +5,8 @@ pub mod bindings {
 
 pub mod wrappers {
     use crate::bindings::{
-        all_different, branch_IntVar, createVar, createVars, make_vec_intvar, output_vars1,
-        var_sym_break, vec, ConLevel, IntVar, ValBranch, VarBranch,
+        all_different, branch_IntVar, createVar, createVars, int_plus, make_vec_intvar,
+        output_vars1, var_sym_break, vec, ConLevel, IntVar, ValBranch, VarBranch,
     };
     use core::ptr;
 
@@ -61,4 +61,10 @@ pub mod wrappers {
             var_sym_break(x);
         }
     }
+
+    pub unsafe fn int_plus_wrapper(x: *mut IntVar, y: *mut IntVar, z: *mut IntVar) {
+        unsafe {
+            int_plus(x, y, z);
+        }
+    }
 }

solvers/chuffed/src/main.rs

@@ -1,38 +1,4 @@
-use chuffed_rs::bindings::{
-    get_idx, new_dummy_problem, p_addVars, p_print, p_setcallback, vec, ConLevel_CL_DEF, IntVar,
-    VarBranch_VAR_INORDER, VarBranch_VAR_MIN_MIN,
-};
-use chuffed_rs::wrappers::{
-    all_different_wrapper, branch_wrapper, create_vars, output_vars_wrapper, var_sym_break_wrapper,
-};
-
-unsafe fn post_constraints(_n: i32) -> *mut vec<*mut IntVar> {
-    // Create constant
-    let n: i32 = _n;
-    // Create some variables
-    let x: *mut vec<*mut IntVar> = create_vars(n, 0, n, false);
-
-    // Post some constraints
-    all_different_wrapper(x, ConLevel_CL_DEF);
-
-    // Post some branchings
-    branch_wrapper(x as _, VarBranch_VAR_INORDER, VarBranch_VAR_MIN_MIN);
-
-    // Declare output variables (optional)
-    output_vars_wrapper(x);
-
-    // Declare symmetries (optional)
-    var_sym_break_wrapper(x);
-
-    // Return the variable
-    x
-}
-
-// Custom printing function for this problem
-#[no_mangle]
-pub unsafe extern "C" fn callback(x: *mut vec<*mut IntVar>) {
-    print!("First output is: {}", get_idx(x, 0));
-}
+use chuffed_rs::bindings::{new_xyz_problem, solve_xyz};
 
 // Entry point for running this problem
 fn main() {
@@ -46,15 +12,7 @@ fn main() {
     let n: i32 = args[1].parse().expect("Invalid input");
 
     unsafe {
-        let x = post_constraints(n);
-        // make new dummy problem
-        let p = new_dummy_problem();
-        // Call problem.addvars()
-        p_addVars(p, x);
-        // Call problem.setcallback()
-        p_setcallback(p, Some(callback));
-        // Commented out currently as trying to print causes the assertion of
-        // isFixed() in IntVar::getVal() to fail.
-        // p_print(p);
+        let p = new_xyz_problem(n);
+        solve_xyz(p);
     }
 }

solvers/chuffed/tests/chuffed_cpp_run.rs

@@ -0,0 +1,14 @@
+use chuffed_rs::bindings::{new_xyz_problem, solve_xyz};
+
+#[test]
+fn run_cpp_problem() {
+    let n: i32 = 1;
+
+    unsafe {
+        let p = new_xyz_problem(n);
+        solve_xyz(p);
+
+        // Pass test if no crash occurs
+        assert!(true);
+    }
+}

solvers/chuffed/wrapper.cpp

@@ -1,4 +1,5 @@
 #include "./wrapper.h"
+#include "chuffed/flatzinc/flatzinc.h"
 
 DummyProblem *new_dummy_problem() { return new DummyProblem(); }
 void p_addVars(DummyProblem *p, vec<IntVar *> *_searchVars) {
@@ -23,3 +24,79 @@ void branch_IntVar(vec<IntVar *> *x, VarBranch var_branch,
                    ValBranch val_branch) {
   branch(*x, var_branch, val_branch);
 }
+
+// Construct problem with given number of variables
+FlatZinc::FlatZincSpace *new_flat_zinc_space(int intVars, int boolVars,
+                                             int setVars) {
+  return new FlatZinc::FlatZincSpace(intVars, boolVars, setVars);
+}
+
+// add new int var
+void addIntVar(FlatZinc::FlatZincSpace flat_zinc_space,
+               FlatZinc::IntVarSpec *vs, const std::string &name) {
+  flat_zinc_space.newIntVar(vs, name);
+}
+
+class XYZProblem : public Problem {
+
+public:
+  // Constants
+  int n; // number of variables
+
+  // Variables
+  vec<IntVar *> x;
+  vec<IntVar *> y;
+  vec<IntVar *> z;
+
+  XYZProblem(int _n) : n(_n) {
+    // Create vars
+    createVars(x, n, 1, 3);
+    createVars(y, n, 1, 3);
+    createVars(z, n, 1, 3);
+
+    // Post constraints
+    // find x, y, z : int(1..3)
+    // such that x + y = z
+
+    all_different(x);
+
+    for (int i = 0; i < n; i++) {
+      int_plus(x[i], y[i], z[i]);
+    }
+
+    // Branching
+    branch(x, VAR_INORDER, VAL_MIN);
+    branch(y, VAR_INORDER, VAL_MIN);
+    branch(z, VAR_INORDER, VAL_MIN);
+
+    // Declare output variables
+    output_vars(x);
+    output_vars(y);
+    output_vars(z);
+  }
+
+  // Function to print out solution
+  void print(std::ostream &out) override {
+    out << "x = ";
+    for (int i = 0; i < n; i++) {
+      out << x[i]->getVal() << " ";
+    }
+    out << std::endl;
+    out << "y = ";
+    for (int i = 0; i < n; i++) {
+      out << y[i]->getVal() << " ";
+    }
+    out << std::endl;
+    out << "z = ";
+    for (int i = 0; i < n; i++) {
+      out << z[i]->getVal() << " ";
+    }
+    out << std::endl;
+  }
+};
+
+// Create new xyz problem
+void *new_xyz_problem(int n) { return new XYZProblem(n); }
+
+// Solve xyz problem
+void solve_xyz(void *p) { engine.solve((XYZProblem *)p); }

solvers/chuffed/wrapper.h

@@ -1,6 +1,8 @@
 #include "chuffed/branching/branching.h"
 #include "chuffed/core/engine.h"
 #include "chuffed/core/propagator.h"
+#include "chuffed/flatzinc/flatzinc.h"
+#include "chuffed/primitives/primitives.h"
 #include "chuffed/vars/modelling.h"
 
 class DummyProblem {
@@ -25,3 +27,6 @@ void destroy_vec_intvar(vec<IntVar *> *v);
 
 void branch_IntVar(vec<IntVar *> *x, VarBranch var_branch,
                    ValBranch val_branch);
+
+void *new_xyz_problem(int n);
+void solve_xyz(void *p);

solvers/chuffed/xyz.fzn

@@ -0,0 +1,7 @@
+predicate all_different_int(array [int] of var int: xs);
+var 1..3: x:: output_var ;
+var 1..3: y:: output_var ;
+var 1..3: z:: output_var ;
+constraint int_lin_eq([1,1,-1],[x,y,z],0);
+solve :: int_search([x, y, z], input_order, indomain_min, complete)
+ satisfy;