Add instances for List, Tuple and Map?

[anttih]

Maps could be read in from a list of pairs, using the List and Tuple IsForeign instances.

I think there should be a defacto way to read in key-value pairs somehow, but I'm not sure if they should be added to this project or to those specific libraries. I could wrap Map in a newtype, but like I said, I really think we should be able to read Maps.

[anttih]

Avoiding creating lots of dependencies here, or foreign dependency in lists, maps and tuples, maybe this warrants it's own foreign-extras library?

Edit: obviously this would require newtypes...

[garyb]

I think from previous discussions we'd kinda agreed to avoid providing default IsForeign instances for PureScript types. The meaning of Foreign currently is purely about direct safe coercion of types from Javascript - if we add instances for common PureScript types it confuses the matter a little, as it's more like a parser then.

[anttih]

Yeah, that makes sense. Maybe the answer here is use argonaut or a newtype.