[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: "Like `let*' but ....."
|
From: |
Clément Pit-Claudel |
|
Subject: |
Re: "Like `let*' but ....." |
|
Date: |
Tue, 24 Jan 2017 16:26:55 -0500 |
|
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.5.1 |
On 2017-01-24 16:12, Alan Mackenzie wrote:
> What is not clear is precisely HOW `pcase' patterns are used for
> bindings, and what the semantics of (PAT EXP) are.
Hi Alan,
I find that mentally translating (pcase-let* ((<x> <y>)) <z>) to (pcase <y>
(<x> <z>)) helps. This translation is mostly correct, with the added twist
that the former is undefined if <y> doesn't match <x>.
Then everything is as in the pcase documentation. Hopefully this helps!
Cheers,
Clément.