Handle eof in comments and do not prematurely close file handler

parser.go

@@ -40,7 +40,6 @@ func NewParser(reader io.Reader) *Parser {
 // NewFileParser will create and initialize a new Parser from a provided from a filename string
 func NewFileParser(filename string) (*Parser, error) {
 	reader, err := os.Open(filename)
-	defer reader.Close()
 	if err != nil {
 		return nil, err
 	}

scanner.go

@@ -167,7 +167,7 @@ func (scanner *Scanner) parseComment() {
 	scanner.curTok.Literal = ""
 	for {
 		scanner.readRune()
-		if scanner.curCh == '\n' {
+		if scanner.curCh == '\n' || scanner.curCh == eof {
 			break
 		}
 		scanner.curTok.Literal += string(scanner.curCh)