From pdalgd at gmail.com  Sun Jan 23 17:50:03 2011
From: pdalgd at gmail.com (peter dalgaard)
Date: Sun, 23 Jan 2011 17:50:03 +0100
Subject: [Rd] "+" operator on characters revisited
In-Reply-To: <878vycd7ld.fsf@gmail.com>
References: <878vycd7ld.fsf@gmail.com>
Message-ID: <E410A01D-653A-434F-B971-9EAC08324AC8@gmail.com>


On Jan 22, 2011, at 21:08 , Vitalie S. wrote:

> The only definite argument occurred in the thread against "+" operator
> was the lack of commutativity (as if one have to prove algebraic
> theorems in R).

I think the real killer was associativity, combined with coercion rules: 

Is "x"+1+2 supposed to be equal to "x12" or "x3"?

-- 
Peter Dalgaard
Center for Statistics, Copenhagen Business School
Solbjerg Plads 3, 2000 Frederiksberg, Denmark
Phone: (+45)38153501
Email: pd.mes at cbs.dk  Priv: PDalgd at gmail.com



[Rd] "+" operator on characters revisited
peter dalgaard