(If this goes through twice, sorry; I posted my response and then it left it blank for some reason, so I'll write it again.) According to my professor, やら is kind of like ~かわからない. In this case, it probably is something closer to か/かどうか. For example: わたしには何のことやらさっぱりわからない。
Apparently, 'やら' is similar to using 'や' or 'とか' but indicates less certainty, and also has other uses as well. For example: "彼のクローゼットには、帽子やスカーフはありました。" "In his closet, there were things like caps and scarves." as opposed to: "彼のクローゼットには、帽子やらスカーフはありました。" "In his closet, (I'm fairly certain... I think) there were things like caps and scarves (or something like that)." Although it apparently (according to The Handbook of Japanese Grammar by Harold G. Henderson) has other usages, in this case this is how it would be used. I heard it used in the sentence: 「試してみるのか？お前が言う光とやらの力を？」 I take this to mean: "Are you trying this? The power of this(uncertain of meaning)light you speak of?" Apparently とやら is the same as やら. I'm not really sure, there doesn't seem to be much info on this anywhere. ***EDIT: とやら actually means "and the like" and works similarly to "nado" but once again, with less certainty and more of that "something-like-that" nuance. So the previous sentence actually should translate to: "The power of this 'light' (and such/and the like/ and stuff like that) that you speak of." To be honest, it sounds like "and stuff like that" would be the closest definition. The words you are listing are said with partial certainty, and like the previous commenter said, や and とか can often be translated to "and."
Is this a dialect? I have never heard it used in hokkaido or the tohoku area.
I disagree, やら やら seems to translate into English as 'Things like...' or 'Do things like...' while や、や、など translates more accurately as 'and, and, etc.' など states explicitely that there are further things in the category, やら やら only implies it.
I think it expresses feeling and a bit of a sense of that's bad/unfortunate?
I'm confused. What is the difference between using 「やら、やら」 and 「や、 など」?