Validity checks about elm-css HOT 4 CLOSED

@rtfeldman While working on #105 I noticed that propN methods are sometimes used with multiple type aliases that do not have a notion of warnings attached to them, like textDecoration3:

textDecoration3 : TextDecorationLine compatibleA -> TextDecorationStyle compatibleB -> ColorValue compatibleC -> Mixin
textDecoration3 =
  prop3 "text-decoration"

So I left them untouched for the time being. Once we are sure that these types have error handling as well, we could incorporate propN functions to pass through warnings as well and that would clean up the code again.

from elm-css.

Now that ~ just resolves mixins, I think the properties themselves can handle these - and with context. Just need to have InvalidStyle build up an error message context instead of being a no-op so often, and have stuff like prop1 incorporate the notion of adding to the error context.

Then we can get fail fast, nice error messages, etc.

from elm-css.

Yep, makes sense to me!

from elm-css.

Closing in favor of #327

from elm-css.