Filtering on Parseable String Filter Failing

[robertervin]

Plywood.ply()
.apply("my_datasource", $("my_datasource")
      .filter(
        $("timestamp").in({
          start: new Date("2018-01-01"),
          end: new Date("2018-02-16")
        })
      )
      .apply('visitorTypes', $("my_datasource")
             .split({ UserId: '$user__id' })
             .apply('user__is_new', $("my_datasource").max('$user__is_first_session'))
       )
      .filter('$user__id in [$visitorTypes.filter($user__is_new == 1).collect($UserId)]')
)
.apply("count", $("my_datasource").count())

Fails with

Expression parse error: Expected "$", "+", "-", "false", "i$", "null", "ply", "true", "|", (, Name, Number, NumberSet, String, or StringSet but "[" found. on '$user__id in [$visitorTypes.collect($UserId)]'

While

.filter($('user__id').in(
    $('visitorTypes').filter('$user__is_new == 1').collect('$UserId')
))

Doesn't throw that error (but still fails due to #166)

[robertervin]

After hunting around into it more, it seems that we need to add a RefExpression possibility to the ComparisonExpression rules in expression.pegjs to parse it correctly.

@vogievetsky Am I on the right track here?

[robertervin]

Actually. After looking into the expression parser, I realized I simply needed to remove the brackets around the RefExpression.

e.g. instead of $user__id in [$visitorTypes.filter($user__is_new == 1).collect($UserId)] it's $user__id in $visitorTypes.filter($user__is_new == 1).collect($UserId)

Closing this issue :)