[ruby-core:74264] [Ruby trunk Feature#12110] Create a method to avoid vacuous truth?

Issue #12110 has been updated by Tsuyoshi Sawada.


Martin D端rst wrote:
> But this isn't so much because that's how natural language works.

That is how natural language works. Presupposition (failure) is an essential part of natural language semantics. It is a matter of semantics, not pragmatics. Presupposition and implicature are different.

> It is more because natural language is used in context

Natural language exists without context. Sentences can be judged to be syntactically correct and can be semantically interpreted irrespective of whether they make sense in context.

> If it's known that the underlying set is empty, then statements with universal quantifications are simply not made, because they are not needed.

Lack of spontaneous data is no obstacle for interpreting them semantically. You can construct a sentence in your mind and judge it by introspection.

----------------------------------------
Feature #12110: Create a method to avoid vacuous truth?
https://bugs.ruby-lang.org/issues/12110#change-57396

* Author: Waldyr de Souza
* Status: Open
* Priority: Normal
* Assignee: 
----------------------------------------
I often find myself running into unexpected results when using #all? for example

[].all? { |e| false } # => true

Even though it's logically correct could we have a method that express the following?

foo.any? && foo.all?(&:bar)



-- 
https://bugs.ruby-lang.org/

Unsubscribe: <mailto:[e-mail]?subject=unsubscribe>
<http://lists.ruby-lang.org/cgi-bin/mailman/options/ruby-core>