Re: how to go from a list of lists to a list of first elements

Aha so there was a link between this example and the scoping discussion (see, this was the context I was missing :-)

Any thoughts on the main question from my message ? ..


William

From: Jos De Roo <josderoo@gmail.com>
Date: Tuesday, January 11, 2022 at 9:28 AM
To: William Van Woensel <william.vanwoensel@gmail.com>
Cc: public-n3-dev@w3.org <public-n3-dev@w3.org>
Subject: Re: how to go from a list of lists to a list of first elements
Yes indeed William, http://ppr.cs.dal.ca:3002/n3/editor/s/MyvdkJpa does not work
but http://ppr.cs.dal.ca:3002/n3/editor/s/qr0in3if works fine.

The reason is that the experimental implementation of log:collectAllIn expects
that all the universals in the where-clause that are not in the select-pattern
must be ground. The built-in is eventually suspended to achieve this grounding.

This is also the reason that Doerthe was not happy with the extended select-pattern
but the answer-list can be simplified again using list:map as shown in the previous email.

Jos

-- https://josd.github.io



On Tue, Jan 11, 2022 at 1:58 PM William Van Woensel <william.vanwoensel@gmail.com<mailto:william.vanwoensel@gmail.com>> wrote:
Hi Jos, Doerthe,
My confusion about this example yesterday stemmed from the fact that it is unclear why “?u” is also being collected, if it is not being used later on. But now I assume it is simply part of the example (and not related to scoping within the collectAllIn builtin, which is what I believe we were talking about :-)?

On that note: as I mentioned yesterday, one could identify at compile time all local variables within the where clause of collectAllIn, but only barring some exceptional circumstances. Such as:
http://ppr.cs.dal.ca:3002/n3/editor/s/tfsdyPr0


(this “pulling in” of universal variables into rules, meaning they become part of the reasoning machinery, was actually a big problem in jen3..)

When compiling this example I found that the following doesn’t seem to work in Eye:
http://ppr.cs.dal.ca:3002/n3/editor/s/zc2tHpTw



Thoughts?

William

From: Jos De Roo <josderoo@gmail.com<mailto:josderoo@gmail.com>>
Date: Monday, January 10, 2022 at 3:03 PM
To: public-n3-dev@w3.org<mailto:public-n3-dev@w3.org> <public-n3-dev@w3.org<mailto:public-n3-dev@w3.org>>
Subject: how to go from a list of lists to a list of first elements
This is about the question of Doerthe
[[

Question:

http://ppr.cs.dal.ca:3002/n3/editor/s/Mut5EohI


Would we use built-ins here?
]]

So how to go from a list of lists to a list of first elements?

We could use list:map like is done in http://ppr.cs.dal.ca:3002/n3/editor/s/xrtMG2Xc


Jos

-- https://josd.github.io