Date: Sat, 04 Jul 2020 17:30:29 -0500
From: Westerbly Snaydley <westerbly@gmail.com>
Subject: Re: unexpected behavior with arrays?
To: Shawn Walker <binarycrusader@gmail.com>
Cc: ~duangle/scopes@lists.sr.ht
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On Sat, Jul 4, 2020 at 14:28, Shawn Walker <binarycrusader@gmail.com> 
wrote:

> So if I'm guessing correctly, the borrow checker you're referring to
> is the "view propagation" mechanism?  However, that can't be used with
> the lower-level constructs and some of the APIs?

Correct. Non-unique ("plain") types - the case for most (all?) of the 
low level parts - aren't checked and constructs like `drop` or `view` 
are ignored when used on them.

> I was trying to puzzle out the subtleties between let, local, etc.
> using examples from the tests.  The documentation and test examples
> made it clear enough that local was stack, global was heap, etc. but
> let is still murky to me.  My understanding is that let is generally
> register-based allocation for values unless you use something like
> alloca-x but maybe it's stack too?

globals are the equivalent to data section variables in an AOT program. 
Conceptually they are not the same as something you allocate using 
`malloc`; their lifespan is the same as your program's.

`let` binds a value to a name. Generally it's used to bind the 
immutable result of an expression, in which case it will be stored in a 
virtual register (might be promoted to stack if necessary, but you 
still can't change it).
You can also bind a local/global variable to an alias, or even types 
and other compile-time only objects. This incurs no transformation, the 
only difference is the name by which you call them.

Westerbly (radgeRayden) Snaydley.