Version française
Home     About     Download     Resources     Contact us    

This site is updated infrequently. For up-to-date information, please visit the new OCaml website at

Browse thread
Parsing 64-bit ints in 32-bit OCaml
[ Home ] [ Index: by date | by threads ]
[ Search: ]

[ Message by date: previous | next ] [ Message in thread: previous | next ] [ Thread: previous | next ]
Date: 2009-03-07 (17:23)
From: Jon Harrop <jon@f...>
Subject: Parsing 64-bit ints in 32-bit OCaml

I'm just trying to write efficient functions for div and mod by three. I'd 
like to handle 32- and 64-bit machines with the same code so I tried:

  let gcd3 = match Sys.word_size with
    | 32 -> 715827883
    | 64 -> 3074457345618258603
    | _ -> failwith "Unknown word size"

That works perfectly in 64-bit but breaks OCaml's parser in 32-bit, which dies 

  Integer literal exceeds the range of representable integers of type int

As a workaround, I replaced it with:

  | 64 -> Int64.to_int 3074457345618258603L

Is there a better workaround?

Dr Jon Harrop, Flying Frog Consultancy Ltd.