I get only syntax errors for these expressions on JVERSION Engine: j803/2014-10-19-11:11:11 Library: 8.04.15 Platform: Win 64 Installer: J804 install InstallPath: e:/users/devonmcc/j64-804 Contact: www.jsoftware.com
On Thu, Dec 6, 2018 at 2:31 PM Ric Sherlock <[email protected]> wrote: > Hi Ryan, > I can't reproduce the behaviour you describe. What version are you using? > (++ > |syntax error > | (++ > (@ > |syntax error > | (@ > (@: > |syntax error > | (@: > (\\. > |syntax error > | (\\. > ]a=. 1 + 2 > 3 > ]a=. (1 + 2 > |syntax error > | ]a=:(1+2 > ]a =. (1 + 2 + > |syntax error > | ]a=:( 1+2+ > JVERSION > Engine: j807/j64/linux > Release: commercial/2018-10-04T15:00:41 > Library: 8.07.20 > Platform: Linux 64 > Installer: J807 install > InstallPath: /opt/j/j64_807 > Contact: www.jsoftware.com > > On Wed, Dec 5, 2018 at 5:50 PM 'Ryan H' via General <[email protected] > > > wrote: > > > Hi everyone, > > > > While randomly entering expressions, I came across strange behavior in > the > > parser. An unmatched left parentheses followed by certain parts of speech > > will not cause a syntax error. Instead, nothing will be printed: > > > > (++ NB. these all print nothing > > (@ > > (@: > > (\\. > > ]a =. 1 + 2 NB. working correctly > > 3 > > ]a =. (1 + 2 NB. prints nothing > > ]a =. (1 + 2 + NB. errors > > |syntax error > > | ]a=:(1+ 2+ > > > > As you can see from the last example, though, syntax errors are still > > thrown when the expression on the right is invalid. But, if the > expression > > on the right is valid, the left parentheses seems to "eat" it and cause > the > > whole sentence to do nothing. > > > > I don't know the internals of the parser, but the "trace" utility seems > to > > confirm that something is wrong here: > > > > trace '(++' > > --------------- 6 Bident ----- > > + > > + > > + + > > |assertion failure: parse > > | *(mark+cavn,0)bwand>(<1 2;0){stack['stack must be empty or has a > > single noun, verb, adverb, or conj' > > > > I hope this is helpful. J is a great language and I want to see it get > > even better. > > > > Best, > > Ryan > > ---------------------------------------------------------------------- > > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm -- Devon McCormick, CFA Quantitative Consultant ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
