should the text for RIGHT_ASSIGN be -> in getParseData()?
On 13-07-05 7:40 AM, peter dalgaard wrote:
On Jul 5, 2013, at 13:29 , Duncan Murdoch wrote:
On 13-07-05 3:31 AM, Yihui Xie wrote:
Hi, The text column for '->' becomes '<-' in the data frame returned by getParseData():
getParseData(parse(text='1->x'))
line1 col1 line2 col2 id parent token terminal text 7 1 1 1 4 7 0 expr FALSE 1 1 1 1 1 1 2 NUM_CONST TRUE 1 2 1 1 1 1 2 7 expr FALSE 3 1 2 1 3 3 7 RIGHT_ASSIGN TRUE <- 4 1 4 1 4 4 6 SYMBOL TRUE x 6 1 4 1 4 6 7 expr FALSE Is that expected?
It's by design, but I agree it's not ideal. The reason for it is that "1 -> x" is parsed as `<-`(x, 1). I think the parser only does translations like this for -> and ->>. Currently the parser shows the name of the binary operator as the text. I'll look into adding special handling for translations like this. We will still parse the assignment in the same way, but the getParseData text could be the true text.
Just watch out for potential complications, e.g.
`->`(x,1)
Error: could not find function "->" so one needs to be sure that nothing will assume that the text column is a function name.
R itself doesn't make use of the text column, it's for display of code by highlighters etc. So if anyone does assume text is a function name, it's their bug, not ours. In fact, the bug is already there, because there is actually one other example which was being parsed properly, "**" is translated to "^". There's no `**` function, but 2**3 works. Duncan Murdoch Duncan