Use rune cast for single rune

Author: mrclmr

tree/peg.go

@@ -641,13 +641,13 @@ func (t *Tree) Compile(file string, args []string, out io.Writer) (err error) {
 				s = s.Complement(t.EndSymbol - 1)
 			case TypeString, TypeCharacter:
 				consumes = true
-				s.Add([]rune(n.String())[0])
+				s.Add(rune(n.String()[0]))
 			case TypeRange:
 				consumes = true
 				element := n.Front()
-				lower := []rune(element.String())[0]
+				lower := rune(element.String()[0])
 				element = element.Next()
-				upper := []rune(element.String())[0]
+				upper := rune(element.String()[0])
 				s.AddRange(lower, upper)
 			case TypeAlternate:
 				consumes = true