Print matched content in color

main.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"os"
 	"slices"
+
+	"github.com/fatih/color"
 )
 
 const CONCAT rune = '~'
@@ -44,7 +46,7 @@ func shuntingYard(re string) string {
 		}
 	}
 
-	fmt.Println(string(re_postfix))
+	// fmt.Println(string(re_postfix))
 
 	opStack := make([]rune, 0)  // Operator stack
 	outQueue := make([]rune, 0) // Output queue
@@ -165,12 +167,19 @@ func main() {
 	var re string
 	re = os.Args[1]
 	re_postfix := shuntingYard(re)
-	fmt.Println(re_postfix)
-	start := thompson(re_postfix)
-	s, e, matched := match(start, os.Args[2])
+	// fmt.Println(re_postfix)
+	startState := thompson(re_postfix)
+	start, end, matched := match(startState, os.Args[2])
 	if matched {
-		fmt.Printf("Matched from %d to %d\n", s, e)
+		for i, c := range os.Args[2] {
+			if i >= start && i < end {
+				color.New(color.FgRed).Printf("%c", c)
+			} else {
+				fmt.Printf("%c", c)
+			}
+		}
+		fmt.Printf("\n")
 	} else {
-		fmt.Printf("No match found.\n")
+		fmt.Println(os.Args[2])
 	}
 }