[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

*To*: srfi-113@xxxxxxxxxxxxxxxxx*Subject*: checking set intersection*From*: Alex Shinn <alexshinn@xxxxxxxxx>*Date*: Fri, 20 Dec 2013 09:25:56 +0900*Delivered-to*: srfi-113@xxxxxxxxxxxxxxxxx*Dkim-signature*: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:date:message-id:subject:from:to:content-type; bh=oTv7C+9lXQZ7v+yCORw7u1OmOlM20NSH4Pmeb483qIM=; b=NyPbH58Xb6dniVKCKlvgcl3fS1It+SyM+mPjdYqrmJOBaqa7NeaeqFI0v1Et+HqlTE /uYW5dN9UKV+vcloFZV+u4vBEpItz5uvKnRHpxwrgQnYfU1cM4GoZQpEjdgFGTT9e1lN oCKwKLgWmJ6+YJx+cCc7yNYQyhh8rtuMADhUUDhGMlrBH8KS0f9ATaFw5ZHyiiiRcl4N 5e6qT2ZFFZNB7aqfhIYqAq3CeEHsE8rLEssFa15RZfu1/Tj1RuCdo6EkmF4OoAMiwX4/ xyiO/DMZNa1PS1h5BE6+5OGQxc3Htn0o7RAUTnMsSRS3qeh3qwnMFyPhpDrfo0lVX250 Io0g==

I've had uses for testing whether two sets

intersect without needing the actual

intersection, so I think the following would

be useful:

(define (set-intersects? a b)

(positive? (set-size (set-intersection a b))))

though it could be implemented much

more efficiently.

I was originally going to write this as

(not (set-empty? ...))

but realized there was no such predicate.

We might want to include that as well.

--

Alex

**Follow-Ups**:**Re: checking set intersection***From:*Kevin Wortman

**Re: checking set intersection***From:*John Cowan

- Prev by Date:
**Re: Open issues for SRFI 113** - Next by Date:
**Re: checking set intersection** - Previous by thread:
**Re: enumeration set case syntax** - Next by thread:
**Re: checking set intersection** - Index(es):