Add line and column calculation.

README.md

@@ -163,4 +163,4 @@ for tok, err, eof := s.Next(); !eof; tok, err, eof = s.Next() {
 }
 ```
 
-// TODO 优化位置标记计算
+//TODO 错误信息的行列计算

lexer.go

@@ -3,6 +3,7 @@ package lexmachine
 import (
 	"bytes"
 	"fmt"
+	"reflect"
 	"unicode/utf8"
 
 	dfapkg "gitea.xintech.co/zhouzhihong/lexmachine/dfa"
@@ -54,7 +55,7 @@ func (t *Token) Equals(other *Token) bool {
 // String formats the token in a human readable form.
 func (t *Token) String() string {
 	return fmt.Sprintf(
-		"%d %q %d (%d, %d)-(%d, %d) (%d, %d)-(%d, %d)",
+		"%d %q %d (%d, %d)-(%d, %d)",
 		t.Type,
 		t.Value,
 		t.TC,
@@ -62,10 +63,6 @@ func (t *Token) String() string {
 		t.StartColumn,
 		t.EndLine,
 		t.EndColumn,
-		t.TSLine,
-		t.TSColumn,
-		t.TELine,
-		t.TEColumn,
 	)
 }
 
@@ -180,14 +177,14 @@ func (s *Scanner) Next() (tok interface{}, err error, eos bool) {
 				col++
 			}
 
-			if (i == match.TC) && token != nil {
+			if (i == match.TC) && reflect.TypeOf(token) == reflect.TypeOf(&Token{}) {
 				token.(*Token).StartLine = line
 				token.(*Token).StartColumn = col
 			}
 			i += sz
 		}
 
-		if token != nil {
+		if reflect.TypeOf(token) == reflect.TypeOf(&Token{}) {
 			token.(*Token).EndLine = line
 			token.(*Token).EndColumn = col
 		}

lexer_test.go

@@ -291,6 +291,7 @@ func TestRegression(t *testing.T) {
 				fmt.Printf("Token: %v\n", tok)
 				found++
 			}
+
 			if found != test.tokens {
 				t.Errorf("Expected exactly %v tokens got %v, ===\nErr: %v\nEOS: %v\nTC: %d\n", test.tokens, found, err, eos, scanner.TC)
 			}