On Tue, 30 Dec 2008, m.u.r. wrote in thread [R] plot.stepfun xlim: > foo <- stepfun(0.5, c(1, 0));
On Wed, Dec 31, 2008 at 4:18 AM, Prof Brian Ripley <rip...@stats.ox.ac.uk> replied: > Why are you adding two blank commands via the semicolons? The R parser (2.8.0 Windows) does not seem to have the concept of blank commands. After all: (using <NL> to represent Newlines below) 1 => 1 1; => 1 (wouldn't a blank command return NULL?) 1;; => ERROR (hmm... seems inconsistent...) {1} => 1 {1 <NL> } => 1 {1;} => 1 {1;;} => 1 {;;;1;;;} => 1 So the extra semi-colons seem to have no semantic effect. The following examples show that there are no blank commands in the abstract (deep) syntax, either: identical(quote({a}),quote({a;})) => TRUE identical(quote({a}),quote({;a})) => TRUE identical(quote({a <NL> b}),quote({a; b})) => TRUE identical(quote({a <NL> b}),quote({a; <NL> b})) => TRUE identical(quote({}), quote({;;;;; <NL><NL> ;;;;;})) => TRUE Unless this is a bug, or I'm missing some subtlety, R's ";" is just concrete (surface) syntax. Why, then, shouldn't users use it any way they like, just like whitespace and comments? It is just a matter of style, isn't it? Are there any good *stylistic* arguments for preferring one to the other? -s ______________________________________________ R-help@r-project.org mailing list https://stat.ethz.ch/mailman/listinfo/r-help PLEASE do read the posting guide http://www.R-project.org/posting-guide.html and provide commented, minimal, self-contained, reproducible code.