Nice example! However, things do not always have a purpose beyond consistency:
Since return(...) is a function call, it gets parsed like any other function call, and can be a part of a more complicated expression. The special semantics of terminating the caller will not take place until the return() subexpression is evaluated (which might not even happen - think function(x) quote(return(pi)) ). Tweaking the R syntax and semantics to special-case return() might be possible, but my gut feeling is that it would just lead to complications further down the line. - pd > On 30 Apr 2025, at 15:27 , Ivan Krylov via R-help <[email protected]> > wrote: > > On Wed, 30 Apr 2025 11:15:02 +0200 > Ralf Goertz via R-help <[email protected]> wrote: > >> If this is not an error what is its purpose? > > From the point of view of the R syntax, everything is an expression. > > One of the uses of return() being an expression is base::callCC(). The > ability to use it inside an expression makes it possible to put it into > a delayed-evaluation object and offer it as a continuation point to > another function. > > Admittedly obscure, but sometimes useful. > > -- > Best regards, > Ivan > > ______________________________________________ > [email protected] mailing list -- To UNSUBSCRIBE and more, see > https://stat.ethz.ch/mailman/listinfo/r-help > PLEASE do read the posting guide https://www.R-project.org/posting-guide.html > and provide commented, minimal, self-contained, reproducible code. -- Peter Dalgaard, Professor, Center for Statistics, Copenhagen Business School Solbjerg Plads 3, 2000 Frederiksberg, Denmark Phone: (+45)38153501 Office: A 4.23 Email: [email protected] Priv: [email protected] ______________________________________________ [email protected] mailing list -- To UNSUBSCRIBE and more, see https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide https://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.
