Question

is there a cleaner way of doing this? I’m trying to do pattern matching of a

(a' option * (char * nodeType) list ref

the only way I found was doing this :

match a with
| _, l -> match !l with
  | (c, n)::t -> doSomething 

Wouldn’t there be a way to match a with something else like …

match a with
| _, ref (c,n)::t -> doSomething

… or something similar? In this example it doesn’t look heavy to just do another match with, but in the real case it can somewhat be…

Thanks for your answers.

Answer 1

The ref type is defined as a record with a mutable field:

type 'a ref = {
    mutable contents : 'a;
}

This means that you can pattern match against it using record syntax like this:

match a with
| _, { contents = (c,n)::t } -> doSomething