[R] Continuation and parse

[Jim Lemon]

Hi gurus,

After an unsuccessful scrabble through the documentation and Jon's 
excellent search facility, I am no wiser as to how R recognizes an 
incomplete command line and politely raises its hand for more. The help 
page for parse gives no indication that it does anything more than spit 
the dummy when fed an incomplete command line, but something in there 
must recognize such ellipsis. Any hints?

Jim