git bindings v1.0

src/api/go/optimize.go

@@ -0,0 +1,218 @@
+package z3
+
+/*
+#include "z3.h"
+#include <stdlib.h>
+*/
+import "C"
+import (
+	"runtime"
+	"unsafe"
+)
+
+// Optimize represents a Z3 optimization context for solving optimization problems.
+// Unlike Solver which only checks satisfiability, Optimize can find optimal solutions
+// with respect to objective functions.
+type Optimize struct {
+	ctx *Context
+	ptr C.Z3_optimize
+}
+
+// NewOptimize creates a new optimization context.
+func (c *Context) NewOptimize() *Optimize {
+	opt := &Optimize{
+		ctx: c,
+		ptr: C.Z3_mk_optimize(c.ptr),
+	}
+	C.Z3_optimize_inc_ref(c.ptr, opt.ptr)
+	runtime.SetFinalizer(opt, func(o *Optimize) {
+		C.Z3_optimize_dec_ref(o.ctx.ptr, o.ptr)
+	})
+	return opt
+}
+
+// String returns the string representation of the optimize context.
+func (o *Optimize) String() string {
+	return C.GoString(C.Z3_optimize_to_string(o.ctx.ptr, o.ptr))
+}
+
+// Assert adds a constraint to the optimizer.
+func (o *Optimize) Assert(constraint *Expr) {
+	C.Z3_optimize_assert(o.ctx.ptr, o.ptr, constraint.ptr)
+}
+
+// AssertAndTrack adds a constraint with a tracking literal for unsat core extraction.
+func (o *Optimize) AssertAndTrack(constraint, track *Expr) {
+	C.Z3_optimize_assert_and_track(o.ctx.ptr, o.ptr, constraint.ptr, track.ptr)
+}
+
+// AssertSoft adds a soft constraint with a weight.
+// Soft constraints are used for MaxSMT problems.
+// Returns a handle to the objective.
+func (o *Optimize) AssertSoft(constraint *Expr, weight string, group string) uint {
+	cWeight := C.CString(weight)
+	cGroup := C.CString(group)
+	defer C.free(unsafe.Pointer(cWeight))
+	defer C.free(unsafe.Pointer(cGroup))
+	
+	sym := o.ctx.MkStringSymbol(group)
+	return uint(C.Z3_optimize_assert_soft(o.ctx.ptr, o.ptr, constraint.ptr, cWeight, sym.ptr))
+}
+
+// Maximize adds a maximization objective.
+// Returns a handle to the objective that can be used to retrieve bounds.
+func (o *Optimize) Maximize(expr *Expr) uint {
+	return uint(C.Z3_optimize_maximize(o.ctx.ptr, o.ptr, expr.ptr))
+}
+
+// Minimize adds a minimization objective.
+// Returns a handle to the objective that can be used to retrieve bounds.
+func (o *Optimize) Minimize(expr *Expr) uint {
+	return uint(C.Z3_optimize_minimize(o.ctx.ptr, o.ptr, expr.ptr))
+}
+
+// Check checks the satisfiability of the constraints and optimizes objectives.
+func (o *Optimize) Check(assumptions ...*Expr) Status {
+	var result C.Z3_lbool
+	if len(assumptions) == 0 {
+		result = C.Z3_optimize_check(o.ctx.ptr, o.ptr, 0, nil)
+	} else {
+		cAssumptions := make([]C.Z3_ast, len(assumptions))
+		for i, a := range assumptions {
+			cAssumptions[i] = a.ptr
+		}
+		result = C.Z3_optimize_check(o.ctx.ptr, o.ptr, C.uint(len(assumptions)), &cAssumptions[0])
+	}
+	return Status(result)
+}
+
+// Model returns the model if the constraints are satisfiable.
+func (o *Optimize) Model() *Model {
+	modelPtr := C.Z3_optimize_get_model(o.ctx.ptr, o.ptr)
+	if modelPtr == nil {
+		return nil
+	}
+	return newModel(o.ctx, modelPtr)
+}
+
+// Push creates a backtracking point.
+func (o *Optimize) Push() {
+	C.Z3_optimize_push(o.ctx.ptr, o.ptr)
+}
+
+// Pop removes a backtracking point.
+func (o *Optimize) Pop() {
+	C.Z3_optimize_pop(o.ctx.ptr, o.ptr)
+}
+
+// GetLower retrieves a lower bound for the objective at the given index.
+func (o *Optimize) GetLower(index uint) *Expr {
+	result := C.Z3_optimize_get_lower(o.ctx.ptr, o.ptr, C.uint(index))
+	if result == nil {
+		return nil
+	}
+	return newExpr(o.ctx, result)
+}
+
+// GetUpper retrieves an upper bound for the objective at the given index.
+func (o *Optimize) GetUpper(index uint) *Expr {
+	result := C.Z3_optimize_get_upper(o.ctx.ptr, o.ptr, C.uint(index))
+	if result == nil {
+		return nil
+	}
+	return newExpr(o.ctx, result)
+}
+
+// GetLowerAsVector retrieves a lower bound as a vector (inf, value, eps).
+// The objective value is unbounded if inf is non-zero,
+// otherwise it's represented as value + eps * EPSILON.
+func (o *Optimize) GetLowerAsVector(index uint) []*Expr {
+	vec := C.Z3_optimize_get_lower_as_vector(o.ctx.ptr, o.ptr, C.uint(index))
+	size := uint(C.Z3_ast_vector_size(o.ctx.ptr, vec))
+	if size != 3 {
+		return nil
+	}
+	return []*Expr{
+		newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, 0)),
+		newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, 1)),
+		newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, 2)),
+	}
+}
+
+// GetUpperAsVector retrieves an upper bound as a vector (inf, value, eps).
+// The objective value is unbounded if inf is non-zero,
+// otherwise it's represented as value + eps * EPSILON.
+func (o *Optimize) GetUpperAsVector(index uint) []*Expr {
+	vec := C.Z3_optimize_get_upper_as_vector(o.ctx.ptr, o.ptr, C.uint(index))
+	size := uint(C.Z3_ast_vector_size(o.ctx.ptr, vec))
+	if size != 3 {
+		return nil
+	}
+	return []*Expr{
+		newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, 0)),
+		newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, 1)),
+		newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, 2)),
+	}
+}
+
+// ReasonUnknown returns the reason why the result is unknown.
+func (o *Optimize) ReasonUnknown() string {
+	return C.GoString(C.Z3_optimize_get_reason_unknown(o.ctx.ptr, o.ptr))
+}
+
+// GetHelp returns help information for the optimizer.
+func (o *Optimize) GetHelp() string {
+	return C.GoString(C.Z3_optimize_get_help(o.ctx.ptr, o.ptr))
+}
+
+// SetParams sets parameters for the optimizer.
+func (o *Optimize) SetParams(params *Params) {
+	C.Z3_optimize_set_params(o.ctx.ptr, o.ptr, params.ptr)
+}
+
+// Assertions returns the assertions in the optimizer.
+func (o *Optimize) Assertions() []*Expr {
+	vec := C.Z3_optimize_get_assertions(o.ctx.ptr, o.ptr)
+	size := uint(C.Z3_ast_vector_size(o.ctx.ptr, vec))
+	result := make([]*Expr, size)
+	for i := uint(0); i < size; i++ {
+		result[i] = newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, C.uint(i)))
+	}
+	return result
+}
+
+// Objectives returns the objectives in the optimizer.
+func (o *Optimize) Objectives() []*Expr {
+	vec := C.Z3_optimize_get_objectives(o.ctx.ptr, o.ptr)
+	size := uint(C.Z3_ast_vector_size(o.ctx.ptr, vec))
+	result := make([]*Expr, size)
+	for i := uint(0); i < size; i++ {
+		result[i] = newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, C.uint(i)))
+	}
+	return result
+}
+
+// UnsatCore returns the unsat core if the constraints are unsatisfiable.
+func (o *Optimize) UnsatCore() []*Expr {
+	vec := C.Z3_optimize_get_unsat_core(o.ctx.ptr, o.ptr)
+	size := uint(C.Z3_ast_vector_size(o.ctx.ptr, vec))
+	result := make([]*Expr, size)
+	for i := uint(0); i < size; i++ {
+		result[i] = newExpr(o.ctx, C.Z3_ast_vector_get(o.ctx.ptr, vec, C.uint(i)))
+	}
+	return result
+}
+
+// FromFile parses an SMT-LIB2 file with optimization objectives and constraints.
+func (o *Optimize) FromFile(filename string) {
+	cFilename := C.CString(filename)
+	defer C.free(unsafe.Pointer(cFilename))
+	C.Z3_optimize_from_file(o.ctx.ptr, o.ptr, cFilename)
+}
+
+// FromString parses an SMT-LIB2 string with optimization objectives and constraints.
+func (o *Optimize) FromString(s string) {
+	cStr := C.CString(s)
+	defer C.free(unsafe.Pointer(cStr))
+	C.Z3_optimize_from_string(o.ctx.ptr, o.ptr, cStr)
+}