Use slices.Contains

This replaces a few loops with a call to slices.Contains. The slices
package was added in Go 1.21.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>

Author: kolyshkin

flag.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"fmt"
 	"regexp"
+	"slices"
 	"strings"
 	"time"
 )
@@ -208,13 +209,7 @@ func FlagNames(name string, aliases []string) []string {
 }
 
 func hasFlag(flags []Flag, fl Flag) bool {
-	for _, existing := range flags {
-		if fl == existing {
-			return true
-		}
-	}
-
-	return false
+	return slices.Contains(flags, fl)
 }
 
 func flagSplitMultiValues(val string, sliceSeparator string, disableSliceSeparator bool) []string {

help.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"slices"
 	"strings"
 	"text/tabwriter"
 	"text/template"
@@ -204,10 +205,8 @@ func cliArgContains(flagName string, args []string) bool {
 			count = 2
 		}
 		flag := fmt.Sprintf("%s%s", strings.Repeat("-", count), name)
-		for _, a := range args {
-			if a == flag {
-				return true
-			}
+		if slices.Contains(args, flag) {
+			return true
 		}
 	}
 	return false
@@ -496,13 +495,11 @@ func checkShellCompleteFlag(c *Command, arguments []string) (bool, []string) {
 		return false, arguments
 	}
 
-	for _, arg := range arguments {
-		// If arguments include "--", shell completion is disabled
-		// because after "--" only positional arguments are accepted.
-		// https://unix.stackexchange.com/a/11382
-		if arg == "--" {
-			return false, arguments[:pos]
-		}
+	// If arguments include "--", shell completion is disabled
+	// because after "--" only positional arguments are accepted.
+	// https://unix.stackexchange.com/a/11382
+	if slices.Contains(arguments, "--") {
+		return false, arguments[:pos]
 	}
 
 	return true, arguments[:pos]