How to present big_int?

Question

I am working with `big_int` type. I looked in the OCaml's library `Pervasives`. For example: in `Int32` ``` let t = 5l Printf.printf "%ld" t ``` How can I define `t` and which `%?d` if I want to declare it is an `big_int`?

Accepted Answer

Below is a toplevel session. The `#load` directive would become a command-line link option if you used the compiler:

```
# #load "nums.cma" ;;
# let t = Big_int.big_int_of_int 5 ;;
val t : Big_int.big_int = <abstr>
# Printf.printf "%s" (Big_int.string_of_big_int t) ;;
5- : unit = ()
```

For numbers that do not fit in a native `int`, use `Big_int.big_int_of_string`. Example: `Big_int.big_int_of_string "99999999999999999999999"`.

The complete list of functions is here.

Finally, the `Big_int` module is quite old and clumsy. The interface dates back to caml-light, in which the module system was rudimentary. This is the reason why each function name redundantly repeats "big_int...". If you are choosing a big integer library now, I would recommend Zarith, which is modern and efficient. The drawback of Zarith is that it is a separate download (for now).

How to present big_int?

Solution

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