elseIfBlock function

Implementation

Parser elseIfBlock() => seq2(
      ref0(elsifTag),
      ref0(elsifBranchContent),
    ).map((values) {
      final elsifTag = values.$1 as Tag;
      final elsifBody = (values.$2 as List).cast<ASTNode>();
      return elsifTag.copyWith(body: elsifBody);
    }).labeled('elseIfBlock');