parse() does not complain for not finished strings?
Philippe Grosjean wrote:
Hello, parse() is supposed to detect incomplete instructions, isn't it? For instance:
# Correct code
msg <- 'log(10)'
mc <- textConnection(msg)
parse(mc)
expression(log(10))
close(mc)
# Now, an incomplete code
msg <- 'log('
mc <- textConnection(msg)
parse(mc)
Error in parse(mc) : unexpected end of input at 2: log(
close(mc)
# Now, another incomplete code (character string not finished)
msg <- 'text <- "some incomplete string'
mc <- textConnection(msg)
parse(mc)
expression(text <- "some incomplete string\n")
close(mc)
I don't understand why parse() does not complain in this third case, and why it "finishes" my string and adds a '\n' at its end. Does anybody could explain me,... or is this a bug
A buglet at least. It is not parsing per se that does it:
> parse(text=msg)
Error in parse(text = msg) :
unexpected end of input in "text <- "some incomplete string"
but it happens whenever you parse from a file or connection e.g.
$ cat > xxx
"incom
$ R
[....]
> source("xxx")
> .Last.value
$value
[1] "incom\n"
$visible
[1] TRUE
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