[Haskell-cafe] Names in a record changes read behavior?

Mike Meyer mwm at mired.org
Mon Jul 27 21:01:44 UTC 2015

 On Mon, Jul 27, 2015, 15:56 Brandon Allbery <allbery.b at gmail.com> wrote:

 On Mon, Jul 27, 2015 at 4:25 PM, Mike Meyer <mwm at mired.org> wrote:

 OK, why won't read accept the same syntax as the REPL? I can see wanting
Read and Show to be inverses of each other, though I think it's a bit
misguided. But if we're going to be that strict about them being inverses,
shouldn't we also insist that the READ eval print loop only accept what
read will accept?

Partly because ReadS isn't a very good parser, partly because of compliance
notably:If the constructor is defined using record syntax, the
derived Read will parse only the record-syntax form, and furthermore, the
fields must be given in the same order as the original declaration.

 So why does the REPL read not follow those rules? And is there some way to
use whatever the REPL is using as the read instance in my code?
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