[Haskell-cafe] Why isn't pattern matching lazy by default?

[C.M.Brown]

> It seems GHC does give a warning at compile-time about it, so you did
> get it right the first time :-)

Well the warning happens at compile time certainly. But the irrefutable
pattern error only occurs at runtime.


cmb21$ ghc --make Main.hs
[1 of 1] Compiling Main             ( Main.hs, Main.o )

Main.hs:3:0:
    Warning: Pattern match(es) are overlapped
             In the definition of `f': f ~[] = ...
Linking Main ...



cmb21$ ./a.out
a.out: Main.hs:(3,0)-(4,10): Irrefutable pattern failed for pattern (x :
xs)

Cheers,
Chris.

>
> Thanks for the info,
> Peter
>
>
>