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| author | Soham Chowdhury <chow.soham@gmail.com> | 2017-05-11 15:40:18 -0400 |
|---|---|---|
| committer | Ben Gamari <ben@smart-cactus.org> | 2017-05-11 17:26:18 -0400 |
| commit | 1381c142cd8d030f9997cdc206dcad006c028bbb (patch) | |
| tree | 2275933e04448f0fe06e6a2fa8a9c719537587b5 /testsuite/tests/typecheck | |
| parent | 6f999230e8f955ee61c470d34a02650165643f68 (diff) | |
| download | haskell-1381c142cd8d030f9997cdc206dcad006c028bbb.tar.gz | |
Fix incorrect ambiguity error on identically-named data constructors
Given multiple in-scope constructors with the same name, say `A`, and a
function of type `A -> Int`, say, the compiler reports both a "type `A`
is not in scope" and (incorrectly) an ambiguity error. The latter
shouldn't be there if `DataKinds` isn't enabled.
This issue was recommended to me by @mpickering as a suitable first
task, and the fix was also outlined in the original Trac ticket. It
involved a simple reordering of the steps taken in `lookup_demoted` in
`RnEnv.hs`. The fix is to make the `DataKinds` check happen earlier,
ensuring that the ambiguity check doesn't happen at all if we know the
constructors couldn't have been promoted.
Signed-off-by: Soham Chowdhury <chow.soham@gmail.com>
Reviewers: mpickering, austin, bgamari
Reviewed By: mpickering, bgamari
Subscribers: rwbarton, thomie
GHC Trac Issues: #13568
Differential Revision: https://phabricator.haskell.org/D3547
Diffstat (limited to 'testsuite/tests/typecheck')
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/T1595.stderr | 6 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/tcfail048.stderr | 4 | ||||
| -rw-r--r-- | testsuite/tests/typecheck/should_fail/tcfail053.stderr | 4 |
3 files changed, 10 insertions, 4 deletions
diff --git a/testsuite/tests/typecheck/should_fail/T1595.stderr b/testsuite/tests/typecheck/should_fail/T1595.stderr index 1f999c636b..bed30c42cf 100644 --- a/testsuite/tests/typecheck/should_fail/T1595.stderr +++ b/testsuite/tests/typecheck/should_fail/T1595.stderr @@ -1,6 +1,8 @@ -T1595.hs:8:15: +T1595.hs:8:15: error: Not in scope: type constructor or class ‘DoesNotExist’ + A data constructor of that name is in scope; did you mean DataKinds? -T1595.hs:13:22: +T1595.hs:13:22: error: Not in scope: type constructor or class ‘DoesNotExist’ + A data constructor of that name is in scope; did you mean DataKinds? diff --git a/testsuite/tests/typecheck/should_fail/tcfail048.stderr b/testsuite/tests/typecheck/should_fail/tcfail048.stderr index eaa2e52d36..4c1c300ef8 100644 --- a/testsuite/tests/typecheck/should_fail/tcfail048.stderr +++ b/testsuite/tests/typecheck/should_fail/tcfail048.stderr @@ -1,2 +1,4 @@ -tcfail048.hs:3:8: Not in scope: type constructor or class ‘B’ +tcfail048.hs:3:8: error: + Not in scope: type constructor or class ‘B’ + A data constructor of that name is in scope; did you mean DataKinds? diff --git a/testsuite/tests/typecheck/should_fail/tcfail053.stderr b/testsuite/tests/typecheck/should_fail/tcfail053.stderr index a9b13bd6da..edd1537b14 100644 --- a/testsuite/tests/typecheck/should_fail/tcfail053.stderr +++ b/testsuite/tests/typecheck/should_fail/tcfail053.stderr @@ -1,2 +1,4 @@ -tcfail053.hs:3:12: Not in scope: type constructor or class ‘A’ +tcfail053.hs:3:12: error: + Not in scope: type constructor or class ‘A’ + A data constructor of that name is in scope; did you mean DataKinds? |