We understand the parsing rules as: a =: .... a
to cause =: to have no awareness that 'a' was a part of the far off expression to the right. ----- Original Message ----- From: Roger Hui <rogerhui.can...@gmail.com> To: Programming forum <programm...@jsoftware.com> Cc: Sent: Tuesday, September 9, 2014 12:35 PM Subject: Re: [Jprogramming] Replace one item of a list I don't believe the messages you cited explained it. J syntax consists of word formation as defined by ;: and parsing rules as defined by Section IIE of the dictionary. How is amend-in-place not permitted by either part? On Tue, Sep 9, 2014 at 8:56 AM, Dan Bron <j...@bron.us> wrote: > Ian wrote: > > Then it actually does in-place updating (even though, > > at face value, J syntax does not permit such a thing). > > Roger responded: > > Please explain why this is not permitted by J syntax. > > I believe Ian is expressing a thought recently raised by Erling Hellenas in > [1], which I responded to here: > > http://www.jsoftware.com/pipermail/programming/2014-July/038030.html > > -Dan > > [1] "J and indexed replacement": > http://www.jsoftware.com/pipermail/programming/2014-July/038068.html > > "In most languages indexed replacement is indexed replacement? In J > and > in most functional languages it is not? You get a brand new variable? > So, why give the user the flawed impression he can still do indexed > replacement and do amendments to variables/nouns? And at the same > time > in tacit code we pretend to only have functions? No variables/nouns > to > be amended? Just functional transformations?" > > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm > ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
