Re: [Haskell-cafe] What does "1 = 2" mean in Haskell?

On 24 February 2017 at 08:45, Brandon Allbery wrote:

Literally the only use I've seen for this was a CCC puzzle. However, it is the trivial case of something that is more useful: pattern matching the result of an expression (say, a Data.Map.lookup when you know the key exists).

Can you explain how that will be useful (without a binding)? Will the pattern match be ever actually tried when there is no binding? -harendra