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Subject: Re: [Caml-list] Documentation of the OCaml Lambda Intermediate Language


>1. How are types represented in the lambda IL? (they seem to be implicit but
>it's not clear) This is especially an issue with polymorphic primitives like
>"field" and "apply".

They are implicit.  See "type erasure."  The type checker ensures
that no IL function operates on a value with the wrong type.

Given

	let f x = 3 lsl !x

the compiler generates

	(function x/1031 (lsl 3 (field 0 x/1031)))

It is impossible, if the type system is sound, for x/1031 to be
anything other than a pointer to a block and for the value in
field 0 of that block to be anything other than an integer.

The implementation depends on pointers and integers being the same size.