[Haskell-beginners] Type inference or just ... a typo in a paper?

[Francesco Ariis]

Hello Michael,

Il 18 maggio 2021 alle 17:24 Michael Turner ha scritto:
> I've inherited some Haskell code, which you can find here:
> 
> http://web.cecs.pdx.edu/~mpj/pubs/aug.html
> 
> The text of the accompanying paper says, "we extend the Text class..."
> -- but the identifier "Text" appears nowhere in the code. Is this just
> an error in the paper, or is the Text class getting involved in some
> indirect way, e.g. through String or perhaps because of the line
> "instance Show Tree where . . ."?

In the updated source (`augupdated.hs`) that is missing, but in the
/original/ one (`aug.hs`) I read at line 255

    instance Text Tree where

Which was then replaced with:

    instance Show Tree where

in the updated version.

Weird to know something like `Show` was not named like that in the early
nineties!
—F