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length "foo" doesn't work with -XOverloadedStrings

The extensions to the defaulting rule for -XOverloadedStrings aren't sufficient to make length "foo" typecheck without an annotation. The reason is that we end up with a constraint IsString [a], and we would somehow have to decide to instantiate a to Char to get the hoped-for behaviour.

It would be nice if this could be made to work (perhaps just with -XExtendedDefaultRules), if a solution can be found without too much hacking.

Trac metadata
Trac field Value
Version 6.8.1
Type FeatureRequest
TypeOfFailure OtherFailure
Priority low
Resolution Unresolved
Component Compiler
Test case
Differential revisions
BlockedBy
Related
Blocking
CC
Operating system Unknown
Architecture Unknown
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