Refactoring: move query tree to deb package.

deb/query.go

@@ -0,0 +1,58 @@
+package deb
+
+// PackageQuery is interface of predicate on Package
+type PackageQuery interface {
+	Matches(pkg *Package) bool
+}
+
+// OrQuery is L | R
+type OrQuery struct {
+	L, R PackageQuery
+}
+
+// AndQuery is L , R
+type AndQuery struct {
+	L, R PackageQuery
+}
+
+// NotQuery is ! Q
+type NotQuery struct {
+	Q PackageQuery
+}
+
+// FieldQuery is generic request against field
+type FieldQuery struct {
+	Field    string
+	Relation int
+	Value    string
+}
+
+// DependencyQuery is generic Debian-dependency like query
+type DependencyQuery struct {
+	Dep Dependency
+}
+
+// Matches if any of L, R matches
+func (q *OrQuery) Matches(pkg *Package) bool {
+	return q.L.Matches(pkg) || q.R.Matches(pkg)
+}
+
+// Matches if both of L, R matches
+func (q *AndQuery) Matches(pkg *Package) bool {
+	return q.L.Matches(pkg) && q.R.Matches(pkg)
+}
+
+// Matches if not matches
+func (q *NotQuery) Matches(pkg *Package) bool {
+	return !q.Q.Matches(pkg)
+}
+
+// Matches on generic field
+func (q *FieldQuery) Matches(pkg *Package) bool {
+	panic("not implemented yet")
+}
+
+// Matches on dependency condition
+func (q *DependencyQuery) Matches(pkg *Package) bool {
+	return pkg.MatchesDependency(q.Dep)
+}