[Haskell-cafe] Automatic derivation (TemplateHaskell?)

Jules Bean jules at jellybean.co.uk
Thu Apr 5 08:25:20 EDT 2007


Jules Bean wrote:
> data paramType = JNum | JBool | JStr
>
> paramParser JNum  = numExpr
> paramParser JBool = boolExpr
> paramParser JStr  = strExpr
>
> unary x pt = reserved (quasiShow (x undefined)) >> parens (paramParser 
> pt) >>= return . x
>
> strCall = choice ( map unary 
> [ELDateToString,TextGetString,LowerStr,UpperStr,Spaces] )
>
>

Oops.

unary (x,pt) = reserved (quasiShow (x undefined)) >> parens (paramParser 
pt) >>= return . x

strCall = choice ( map unary   
                     [(ELDateToString,JNum),(TextGetString,JNum),
                      (LowerStr,JStr),(UpperStr,JStr),(Spaces,JStr)] )

(have to specify the param types)

Jules



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