Syntactic sugar to write the recursion in GHC

The recursion is defined by two case that are a base case and a recursive case.\\ Instead of writing two functions to describe the recursion, I propose to write a single function that makes both.\\

<op> should be set to tell the compiler how to compile the function.\\

syntaxe :

exp = <base_case_exp1;...;base_case_expn> <op>
<recursive_case_exp1;...;recursive_case_expn>
<recursive_case_guards>

examples:

fac :: Int -> Int
fac n = 0 = 1 <op> n * fac (n-1)

product :: Num a => [a] -> a
product (n:ns) = [] = 1 <op> n * product ns

reverse :: [a] -> [a]
reverse (x:xs) = [] = [] <op> reverse xs ++ [x]

insert :: Ord a => a -> [a] -> [a]
insert x (y:ys) = x [] = [x] <op> | x <= y = x:y:ys
                                  | otherwise = y:insert x ys

drop :: Int -> [a] -> [a]
drop n (_:xs) = 0 xs = xs; _ [] = [] <op> drop (n-1) xs

fib :: Int -> Int
fib n = 0 = 0; 1 = 1 <op> fib (n-2) + fib (n-1)

If someone is interested in this, I encourage him to write a proposal. I don't know how to do it.

Trac metadata

Trac field	Value
Version	8.0.2
Type	FeatureRequest
TypeOfFailure	OtherFailure
Priority	normal
Resolution	Unresolved
Component	Compiler
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