OCaml中此空列表检查（list = []）的任何副作用？

Question

In OCaml, when having to check for the emptiness of a list data structure lst , I would like to use

if (lst = []) then ...

for its conciseness, instead of using pattern matching or checking length of the list.

I wonder if there is any side effect of this structural comparison (=) over the list data structure?

Answer 1

There are no side effects. It's a perfectly good way to test whether a list is empty.

Many times however, you'd like to work with some elements of the list if it's not empty. Pattern matching is good for those times.

As a tiny side comment, if you're interested in conciseness you don't need the parentheses in your if .