Added some more documentation, why types are not exported

claims.go

@@ -9,6 +9,9 @@ import (
 // Claims must just have a Valid method that determines
 // if the token is invalid for any supported reason
 type Claims interface {
+	// Valid implements claim validation. The opts are function style options that can
+	// be used to fine-tune the validation. The type used for the options is intentionally
+	// un-exported, since its API and its naming is subject to change.
 	Valid(opts ...validationOption) error
 }
 

parser_option.go

@@ -33,6 +33,6 @@ func WithoutClaimsValidation() ParserOption {
 // WithLeeway returns the ParserOption for specifying the leeway window.
 func WithLeeway(d time.Duration) ParserOption {
 	return func(p *Parser) {
-		p.validationOptions = append(p.validationOptions, withLeewayValidator(d))
+		p.validationOptions = append(p.validationOptions, withLeeway(d))
 	}
 }

validator_option.go

@@ -4,17 +4,25 @@ import "time"
 
 // validationOption is used to implement functional-style options that modify the behavior of the parser. To add
 // new options, just create a function (ideally beginning with With or Without) that returns an anonymous function that
-// takes a *ValidatorOptions type as input and manipulates its configuration accordingly.
+// takes a *validator type as input and manipulates its configuration accordingly.
+//
+// Note that this struct is (currently) un-exported, its naming is subject to change and will only be exported once
+// the API is more stable.
 type validationOption func(*validator)
 
 // validator represents options that can be used for claims validation
+//
+// Note that this struct is (currently) un-exported, its naming is subject to change and will only be exported once
+// the API is more stable.
 type validator struct {
 	leeway time.Duration // Leeway to provide when validating time values
 }
 
-
-// withLeewayValidator is an option to set the clock skew (leeway) windows
-func withLeewayValidator(d time.Duration) validationOption {
+// withLeeway is an option to set the clock skew (leeway) window
+//
+// Note that this function is (currently) un-exported, its naming is subject to change and will only be exported once
+// the API is more stable.
+func withLeeway(d time.Duration) validationOption {
 	return func(v *validator) {
 		v.leeway = d
 	}