Locations and tokens are now capable of creating errors on their own

file/error.go

@@ -22,9 +22,9 @@ func NewError (
 	message string,
 	kind ErrorKind,
 ) (
-	err *Error,
+	err Error,
 ) {
-	return &Error {
+	return Error {
 		Location: location,
 		message:  message,
 		kind:     kind,

file/location.go

@@ -8,3 +8,8 @@ type Location struct {
 	column int
 	width  int
 }
+
+// NewError creates a new error at this location.
+func (location Location) NewError (message string, kind ErrorKind) (err Error) {
+	return NewError(location, message, kind)
+}

lexer/token.go

@@ -86,6 +86,11 @@ func (token Token) Location () (location file.Location) {
 	return token.location
 }
 
+// NewError creates a new error at this token's location.
+func (token Token) NewError (message string, kind file.ErrorKind) (err file.Error) {
+	return token.location.NewError(message, kind)
+}
+
 // Describe generates a textual description of the token to be used in debug
 // logs.
 func (token Token) Describe () (description string) {