Proposal: Improving the IsString String instance

Henning Thielemann schlepptop at
Mon Aug 26 19:10:27 CEST 2013

Am 26.08.2013 19:03, schrieb Gabriel Gonzalez:
> May I propose an alternative solution?  Why not just add a syntactic way
> to selectively opt in or out of `OverloadedStrings` for certain string
> literals?  It could be something as simple as Python's trick for
> prefixing string literals with a single character to either enable or
> disable the overloading:
>      example1 :: Int
>      example1 = length "Non-overloaded string"
>      example2 :: Parser Int
>      example2 = o"Overloaded string" *> pure 4
> ... but it doesn't have to be that specific solution.  All that really
> matters is that it is syntactically lightweight.

This "opting in" already exists: Just put a space between o and the 
quotation mark and define "o = fromString". It's Haskell 98.

I would prefer that solution to all syntactic extension experiments.

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