The way I do terminal codes in Hoogle is to define a type, TagStr:
data TagStr = Str String | Tags [TagStr] | Underline TagStr | Bold TagStr | Color Int TagStr
Now instead of dumping out escape codes, I dump out TagStr's, and then have a routine that converts from TagStr -> String with escape codes. This has the massive advantage that on OS's that don't support escape codes, I can use exactly the same generation code, and then drop the escape codes very simply.
You should note that this is in large part what hat already does. Look at the Highlight Module. Bob
HatCoverText -> Tracing.Hat.Coverage.ANSIterm
The name ANSIterm makes me uneasy, Terminal perhaps? ANSIterm just looks ugly, and the case of it is weird compared to the rest of Haskell.
In general we now seem to be pretty much in agreement about the proposed structure.
I can't see any major problems with it. Bob