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Opened by Oleg Grenrus@phadejDeveloper

Cannot have type variable named `role`

data Policy role = Policy

fails with

GHCi, version 8.10.2: https://www.haskell.org/ghc/  :? for help
[1 of 1] Compiling Main             ( Role.hs, interpreted )

Role.hs:1:13: error: parse error on input ‘role’
  |
1 | data Policy role = Policy
  |                   ^^^^

In GHC-7.6.3 (pre roles) this code is fine.

Similarly

data Policy family = Policy

Fails In GHC-7.8..GHC-8.10, but is fine with GHC-7.6.

The https://downloads.haskell.org/ghc/8.10.2/docs/html/users_guide/bugs.html#lexical-syntax mentions only forall as extra keyword (data Policy forall = Policy become invalid in GHC-8.8). I'd expect role and family to be either mentioned in lexical syntax divergence section, or made to work. Both seem to be fine as term identifiers.

EDIT: also the error messages is unhelpful. The parser error should mention that role, (family, forall) are interpreted as keyword

Edited by Oleg Grenrus