add per expression negation

Author: jambit-admin

main.go

@@ -6,6 +6,7 @@ import (
 	"log"
 	"os"
 	"regexp"
+	"strings"
 
 	"github.com/moepi/nexus-cli/registry"
 	"github.com/urfave/cli"
@@ -183,11 +184,16 @@ func filterTagsByRegex(tags []string, expressions []string, invert bool) ([]stri
 	}
 	for _, tag := range tags {
 		for _, expression := range expressions {
+			var expressionInvert = invert
+			if strings.HasPrefix(expression, "!") {
+				expressionInvert = !invert
+				expression = strings.Trim(expression, "!")
+			}
 			retVal, err := regexp.MatchString(expression, tag)
 			if err != nil {
 				return retTags, err
 			}
-			if retVal == !invert {
+			if retVal == !expressionInvert {
 				retTags = append(retTags, tag)
 				// tag must match any expression, so continue with next tag on match
 				break