[Haskell-cafe] Solving the configuration problem with parametrized modules

[Erik de Castro Lopo]

Joachim Breitner wrote:

> The big downside is the verbosity of the approach: A lot of parameters
> need to be passed, and if one such value is suddenly required in a
> function where it was not before, this function’s signature and all
> functions using it have to be modified. Also, I expect that the explicit
> passing causes a small performance penalty.

Can't this be mostly solved by putting all these configuration parameters
in a struct and then using implicit parameters:

    http://www.haskell.org/ghc/docs/latest/html/users_guide/other-type-extensions.html#implicit-parameters

The nice thig about this approach is that is not a single unsafe operation
needed.

Erik
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Erik de Castro Lopo
http://www.mega-nerd.com/