@@ -211,6 +211,21 @@ func (b *Builder) dispatch(stepN int, ast *parser.Node) error {

 		msg += " " + ast.Value

 	}

+	// count the number of nodes that we are going to traverse first

+	// so we can pre-create the argument and message array. This speeds up the

+	// allocation of those list a lot when they have a lot of arguments

+	cursor := ast

+	var n int

+	for cursor.Next != nil {

+		cursor = cursor.Next

+		n++

+	}

+	l := len(strs)

+	strList := make([]string, n+l)

+	copy(strList, strs)

+	msgList := make([]string, n)

+

+	var i int

 	for ast.Next != nil {

 		ast = ast.Next

 		var str string

@@ -218,16 +233,18 @@ func (b *Builder) dispatch(stepN int, ast *parser.Node) error {

 		if _, ok := replaceEnvAllowed[cmd]; ok {

 			str = b.replaceEnv(ast.Value)

 		}

-		strs = append(strs, str)

-		msg += " " + ast.Value

+		strList[i+l] = str

+		msgList[i] = ast.Value

+		i++

 	}

+	msg += " " + strings.Join(msgList, " ")

 	fmt.Fprintln(b.OutStream, msg)

 	// XXX yes, we skip any cmds that are not valid; the parser should have

 	// picked these out already.

 	if f, ok := evaluateTable[cmd]; ok {

-		return f(b, strs, attrs, original)

+		return f(b, strList, attrs, original)

 	}

 	fmt.Fprintf(b.ErrStream, "# Skipping unknown instruction %s\n", strings.ToUpper(cmd))