Here is a nice discussion about fexprs: http://lambda-the-ultimate.org/node/3640
On Tuesday, 26 April 2016 23:04:09 UTC+2, tbc++ wrote: > > Congradulations! You've discovered Fexprs! An ancient technology from a > by-gone age: https://en.wikipedia.org/wiki/Fexpr > > On Tue, Apr 26, 2016 at 2:23 PM, Olek <aleksand...@gmail.com <javascript:> > > wrote: > >> Yes, the delay and force does the job. Now it would be nice to hide delay >> declaration in arguments destruction as already proposed: >> >> (den mycrazyif [ statement ~onsuccess ~onfailure ] ; nonsuccess and on >> failure becomes delay objects >> (if statement ; just evalutated with mycrazyif call >> @onsucess ; deref block in case of success >> @onfailure)) ; deref block in case of failure >> >> >> On Tuesday, 26 April 2016 19:59:12 UTC+2, Michael Griffiths wrote: >>> >>> I'm not sure I fully understand your proposal, but when I really need >>> lazy evaluation (which is pretty rare) I reach for `delay` and `force`. >>> >>> On Tuesday, 26 April 2016 16:41:08 UTC+1, Olek wrote: >>>> >>>> Hi! >>>> >>>> In short: >>>> >>>> I have noticed that in most cases I use macros only for lazy arguments >>>> evaluation. Why not to make something to use only this feature? It would >>>> be >>>> light version of macro for clojurescript/clojure and easy to grasp for >>>> newcomers and still powerful in programming (with that you could implement >>>> binding/scopes/interpreter pattern). I love implicite use of macros where >>>> from call point of view the user can't distinguish what is function and >>>> what is macro. >>>> >>>> In long: >>>> >>>> Generally the macros are used in compile phase to manipulate AST (or >>>> just data structures because Clojure is homoiconic) to produce code in >>>> order to be consumed in evaluation phase. >>>> It is nice to include new language constructs with use of macros but as >>>> my experience points out for most time I use macros only for changing >>>> evaluation moment/order. >>>> Maybe there should be some construct like "defnlazy" for which you >>>> write normal function but all input arguments are evaluated only when you >>>> explicitly evaluate them. >>>> What we gain? We don't have to deal with # ` @ list eval and separate >>>> thoughts on read/eval phases, but we still must explicitly say ~ to deref >>>> passed block of construct as argument. >>>> >>>> Also there are some problems to grasp: >>>> - is it safe to implicite convert blocks of construct from statements >>>> to deref objects >>>> - how it should behave when you pass not deref object to another >>>> discussed "defnlazy" >>>> - maybe there shouldn't be any defnlazy but you should just implement >>>> it in arguments destruction so you can use constructs like: >>>> >>>> (defn mycrazyif [ statement ~onsuccess ~onfailure ] >>>> (if statement ; just evalutated with mycrazyif call >>>> @onsucess ; deref block in case of success >>>> @onfailure)) ; deref block in case of failure >>>> >>>> >>>> With regards, >>>> Olek >>>> >>> -- >> You received this message because you are subscribed to the Google >> Groups "Clojure" group. >> To post to this group, send email to clo...@googlegroups.com >> <javascript:> >> Note that posts from new members are moderated - please be patient with >> your first post. >> To unsubscribe from this group, send email to >> clojure+u...@googlegroups.com <javascript:> >> 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+u...@googlegroups.com <javascript:>. >> For more options, visit https://groups.google.com/d/optout. >> > > > > -- > “One of the main causes of the fall of the Roman Empire was that–lacking > zero–they had no way to indicate successful termination of their C > programs.” > (Robert Firth) > -- 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/d/optout.
