That billion dollar mistake. In Haskell...?

This is a short observation on 'the billion-dollar mistake' of Hoare, implementing null pointers in Algol W back in 1965. Dereferencing a null pointer usually causes a runtime error immediately terminating the program, and lots of programs crashed due to that.

This mistake is used ad nauseam to plead for safer languages, which made sense at the time since crashing programs had become the default. What is often not told is that runtime exceptions are standard and must be carefully handled in almost all languages. Let's take Haskell, one of the ostensibly claimed safest languages in the world.

Runtime exceptions can occur due to a variety of reasons, applying a partial function outside its domain is one of them. Let's try 'head []' in Haskell.

λ 
> head []
No instance for (Show a0)
arising from a use of ‘show_M340108553800667339831401’
The type variable ‘a0’ is ambiguous
Note: there are several potential instances:
instance Show a => Show (Const a b)
-- Defined in ‘Control.Applicative’
instance Show a => Show (ZipList a)
-- Defined in ‘Control.Applicative’
instance Show GeneralCategory -- Defined in ‘Data.Char’
...plus 44 others
In the expression:
show_M340108553800667339831401 (let e_1 = head [] in e_1)
In an equation for ‘e_134010855380066733983140134010855380066733983140111’:
e_134010855380066733983140134010855380066733983140111
= show_M340108553800667339831401 (let e_1 = head [] in e_1)
In the expression:
(let
e_134010855380066733983140134010855380066733983140111
= show_M340108553800667339831401 (let ... in e_1)
in e_134010855380066733983140134010855380066733983140111) ::
String_M340108553800667339831401

That didn't go too well, Haskell cannot figure out the particular type instance for an empty list. Okay, let's add an assertion.

λ 
> let x = head ([]::[Int]) in x
*Exception: Prelude.head: empty list

And boom, there you have it. Haskell terminates with a runtime exception. In fact, any Haskell program can have this potential 'bomb' in it. 

What, in the abstract, is the difference between 'nullptr.x' and 'head []'? Both terminate the program due to a runtime exception.

I fully agree that Haskell is a safer language than most imperative ones. But that 'billion dollar mistake'? That is in Haskell too.