The thing is, the data contained in the source definition is all still there in the compiled version - but apparently it is not easily accessible. It feels like it must be possible to write a function that looks at a function object and it's class and can produce at least a decent approximation to the original, or at least a clojure list version of the compiled code. No doubt completely faithful recreation wouldn't be possible, not least because of macros.
Also, sometimes, such as when developing possibly, it is not always necessary to have optimum performance. On Tuesday, November 26, 2013 8:30:38 PM UTC, Alex Miller wrote: > > Seems like you lost the clojure mailing list in this response, so I > re-added it. > > On Tue, Nov 26, 2013 at 2:09 PM, henry w <henr...@gmail.com > <javascript:>>wrote: > >> Thanks to all respondents. >> >> This was really just something I was curious about, although I can think >> of some practical uses. >> >> It's just not clear to me still if there is some really good reason code >> stops being data (or at least having an accessible data representation) >> after it is compiled. Jamie has shown it is still data, although in a very >> platform-specific way. Is it just the case that there aren't compelling >> use-cases that people have come up with perhaps? >> > > Code stops being data so it can be a more efficient form to the host > platform (bytecode), which is what makes Clojure perform well. If you > always left the data in the original form, you would just need an > interpreter (and Clojure would be much slower). Clojure is always compiled > as performance is a key concern. > > >> Pratically, some examples of use might be related to the >> https://github.com/clojure/tools.trace library. Here vars are >> temporarily bound to functions that are wrapped versions of the functions >> they held previously in order to print input and output. A nice alternative >> would be to show the function form with the parameters interpolated. >> Another case might be to see not just the source of a function, but to >> 'inline' the source of functions called from it. Or just generally mess >> about with functions I don't own. >> > > There has been a recent enhancement discussion (perhaps here, perhaps > jira, can't find it now) to have functions retain their source definition > at runtime. I'm not sure how that would be possible without significantly > affecting performance and memory footprint however. > > >> >> >> >> On Tuesday, November 26, 2013 7:01:57 PM UTC, Alex Miller wrote: >>> >>> It would help to know what your real goal is, but compiled Clojure does >>> not retain the original source form. >>> >>> One hook you do have though is macros which will be invoked prior to >>> compilation. At macro execution time, you have access to the special &form >>> var which is the original form (as a Clojure data structure). >>> >>> Thus you could write a defn-like macro which when called to define a >>> function definition would define the function and decorate it with meta >>> that included the definition. I am a poor enough macrologist that I will >>> not attempt that here but merely suggest it should be feasible. :) >>> >>> Alex >>> >>> On Thursday, November 21, 2013 12:14:39 PM UTC-6, henry w wrote: >>>> >>>> Say you have a function created like this: >>>> >>>> (fn [x] (+ x y)) >>>> >>>> and then you have a reference to an instance of this function, is there >>>> some way to use the function reference to access the list '(fn [x] (+ x >>>> y)), >>>> including the symbol 'y' (such that you could dereference 'y' and get >>>> its value)? The source function is not the right thing and so far googling >>>> hasn't got me the answer. >>>> >>>> Thanks >>>> >>> > -- -- 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.
