feat: tokenizer accepts braces, line terminator, and equal sign

pkg/saccharine/tokenizer.go

@@ -28,6 +28,19 @@ func parseRune(i *iterator.Iterator[rune], expected func(rune) bool) (rune, erro
 	}
 }
 
+func parseCharacter(i *iterator.Iterator[rune], expected rune) (rune, error) {
+	i2 := i.Copy()
+
+	if r, err := i2.Next(); err != nil {
+		return r, err
+	} else if r != expected {
+		return r, fmt.Errorf("got unexpected rune %v'", r)
+	} else {
+		i.Sync(i2)
+		return r, nil
+	}
+}
+
 // Pulls the next token from an iterator over runes. If it cannot, it will
 // return nil. If an error occurs, it will return that.
 func getToken(i *iterator.Iterator[rune]) (*token.Token, error) {
@@ -53,6 +66,18 @@ func getToken(i *iterator.Iterator[rune]) (*token.Token, error) {
 		return token.NewSlash(index), nil
 	case letter == '\n':
 		return token.NewNewline(index), nil
+	case letter == '{':
+		return token.NewNewline(index), nil
+	case letter == '}':
+		return token.NewNewline(index), nil
+	case letter == ':':
+		if _, err := parseCharacter(i, '='); err != nil {
+			return nil, err
+		} else {
+			return token.NewAssign(index), nil
+		}
+	case letter == ';':
+		return token.NewEnd(index), nil
 	case unicode.IsSpace(letter):
 		return nil, nil
 	case isVariable(letter):