From: Leo White <leo@lpw25.net>
To: caml-list@inria.fr
Subject: Re: [Caml-list] Data representation of records
Date: Tue, 19 Jan 2016 04:07:49 -0500 [thread overview]
Message-ID: <1453194469.2351553.496126650.44E1CE9C@webmail.messagingengine.com> (raw)
In-Reply-To: <CALahJKBRxsNvz4dcd+KSuZFSMhoJeOauXAbyNEEad+cjr72DDg@mail.gmail.com>
> My question is, why records need the labels.
> In my comprehension, there is no chance that we check the label of records.
The "label" is called the tag. Every allocated object in OCaml has a tag. They are stored in the header word and are part of the information used by the GC to traverse OCaml values (they are also used by the non-parametric polymorphic functions like "=" and "Hashtbl.hash"). Tags above a certain number have special meaning for the GC, all the rest are used for ordinary values (records, variants etc.). Records have to be given one of these ordinary tags so it might as well be 0.
Regards,
Leo
prev parent reply other threads:[~2016-01-19 9:08 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-01-19 8:54 Ryohei Tokuda
2016-01-19 9:07 ` Leo White [this message]
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