testsuite/tests/quantified-constraints/T15231.hs · 902ebcc2b95707319d37a19d6b23c342cc14b162 · Reinier Maas / GHC

Forked from Glasgow Haskell Compiler / GHC

5543 commits behind the upstream repository.

6 years ago

Add "quantified constraint" context in error message, fix #15231. · 91822e4e

Tao He authored 6 years ago

This patch adds "quantified constraint" context in error message when
UndecidableInstances checking fails for quantified constraints.
See Trac #15231:comment#1.

This patch also pretty-prints the instance head for better error messages.

Test Plan: make test TEST="T15231"

Reviewers: bgamari, simonpj

Reviewed By: simonpj

Subscribers: simonpj, rwbarton, thomie, carter

GHC Trac Issues: #15231

Differential Revision: https://phabricator.haskell.org/D4819

91822e4e

History

Add "quantified constraint" context in error message, fix #15231.

Tao He authored 6 years ago

This patch adds "quantified constraint" context in error message when
UndecidableInstances checking fails for quantified constraints.
See Trac #15231:comment#1.

This patch also pretty-prints the instance head for better error messages.

Test Plan: make test TEST="T15231"

Reviewers: bgamari, simonpj

Reviewed By: simonpj

Subscribers: simonpj, rwbarton, thomie, carter

GHC Trac Issues: #15231

Differential Revision: https://phabricator.haskell.org/D4819

Code owners

Assign users and groups as approvers for specific file changes. Learn more.

T15231.hs 294 B