Added schema.Exists method

Author: Jesse Coretta

schema.go

@@ -318,6 +318,37 @@ func (r Schema) Push(def Definition) Schema {
 	return r
 }
 
+/*
+Exists returns a Boolean value indicative of whether the receiver instance
+contains a matching [Definition] type and identifier.
+*/
+func (r Schema) Exists(def Definition) (exists bool) {
+	if def == nil {
+		return
+	}
+
+	switch def.Type() {
+	case `ldapSyntax`:
+		exists = !r.LDAPSyntaxes().Get(def.NumericOID()).IsZero()
+	case `matchingRule`:
+		exists = !r.MatchingRules().Get(def.NumericOID()).IsZero()
+	case `attributeType`:
+		exists = !r.AttributeTypes().Get(def.NumericOID()).IsZero()
+	case `matchingRuleUse`:
+		exists = !r.MatchingRuleUses().Get(def.NumericOID()).IsZero()
+	case `objectClass`:
+		exists = !r.ObjectClasses().Get(def.NumericOID()).IsZero()
+	case `dITContentRule`:
+		exists = !r.DITContentRules().Get(def.NumericOID()).IsZero()
+	case `nameForm`:
+		exists = !r.NameForms().Get(def.NumericOID()).IsZero()
+	case `dITStructureRule`:
+		exists = !r.DITStructureRules().Get(def.(DITStructureRule).RuleID()).IsZero()
+	}
+
+	return
+}
+
 /*
 ParseRaw returns an error following an attempt to parse raw into
 usable schema definitions. This method operates similarly to the

schema_test.go

@@ -66,6 +66,12 @@ func ExampleSchema_Push() {
 	// Output: exampleClass
 }
 
+func ExampleSchema_Exists() {
+	var def Definition = mySchema.LDAPSyntaxes().Get(`integer`)
+	fmt.Println(mySchema.Exists(def))
+	// Output: true
+}
+
 func ExampleSchema_Replace_objectClass() {
 
 	gon := mySchema.ObjectClasses().Get(`groupOfNames`)
@@ -203,6 +209,7 @@ func TestSchema_codecov(t *testing.T) {
 		mySchema.DITStructureRules().Index(0),
 	} {
 		mySchema.Replace(def)
+		mySchema.Exists(def)
 	}
 
 	mySchema.Replace(LDAPSyntax{})