On Mon, Apr 29, 2013 at 5:02 PM, Ben Wolfson <wolf...@gmail.com> wrote:
> On Mon, Apr 29, 2013 at 1:57 PM, noahlz <nzuc...@gmail.com> wrote: > >> Ok. The parser reads a single complete expression and discards the rest. >> It understands that once it has hit a new character that represents the >> beginning of a new expression, it doesn't care. >> >> I suppose I thought the parser would raise an error on detecting an >> unmatched parenthesis, but that's wrong. >> >> Interestingly, when I try this at the repl (1.5.1) it errors as I >> expected (probably why I expected it in the first place): >> >> user=> 1000N) >> 1000N >> >> RuntimeException Unmatched delimiter: ) >> clojure.lang.Util.runtimeException (Util.java:219) >> >> >> Of course, the repl doesn't use "read-string." So, the next step in my >> journey is to investigate the source of clojure.main. But - someone wants >> to take the opportunity to ruin the surprise for me - with a more detailed >> explanation / theory discussion - I'm open to it :) >> > > But notice that this *also* returns 1000N, first. So the cases aren't that > different: it managed to read a complete expression, and evaluated it. Then > it tried to read *another* expression from the unconsumed input. The > difference is only that read-string doesn't attempt to exhaust its input > argument. > If you want to exhaust read-string's input argument, getting back a vector of all of the objects in the input and an error if any of them are syntactically invalid, just call (read-string (str "[" in-string "]")). This also deals with empty inputs in a non-blowing-up manner, returning an empty vector, which might allow uniform handling of the cases (empty? in-string) and (not (empty? in-string)) in some instances. -- -- You received this message because you are subscribed to the Google Groups "Clojure" group. To post to this group, send email to clojure@googlegroups.com Note that posts from new members are moderated - please be patient with your first post. To unsubscribe from this group, send email to clojure+unsubscr...@googlegroups.com For more options, visit this group at http://groups.google.com/group/clojure?hl=en --- You received this message because you are subscribed to the Google Groups "Clojure" group. To unsubscribe from this group and stop receiving emails from it, send an email to clojure+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/groups/opt_out.
