One approach would be that you saved the result of each 'p' file in a corresponding 'o' file. If you want to get fancy you could even make it so that if the 'p' were newer the 'o' would be ignored. But manually deleting the 'o' would make that unnecessary.
This leaves some details unspecified -- like should you use ". or 5!:5 or 3!:1 or map_jmf_ in the process of generating the 'o' files? But, anyways, if you defined the interface you could use it. Thanks, -- Raul On Thu, Jul 2, 2020 at 4:48 AM ethiejiesa via Programming <[email protected]> wrote: > > Hey J, > > Wanted to share this and see what you think. > > For Project Euler solutions in J, I have a single file and run it like this: > > $ ./project-euler.ijs <1> [<m> ..] # output answers to problem n, m, ... > > Initially, I had a scheme where all solutions are named like p1, p2, etc. with > the following at the bottom of the script: > > echo ".&> (#~ 0 = 4!:0) 'p'&,&.> ARGV > exit@0:^:(e.~ <@'./project-euler.ijs') ARGV > > It just straightforwardly tacks 'p' to the beginning of all arguments, filters > out the missing/nonsense stuff, and executes the result. The second line > ensures the script exits when called directly but not when 'load'ed in the > jconsole. > > Anyway, the above scheme works but execution starts to get slow as more > solutions accumulate since it ends up computing *all* p1, p2, etc. before > output. So I wanted to "lazily" evaluate only those solutions requested on the > command line. > > My first approach was to "lazy load" by making all p1, p2, etc. strings and > evaluating with > > 0!:111 ".&> (#~ 0 = 4!:0) 'p'&,&.> ARGV > > However, this strikes me as a bit ugly. It also makes it a bit awkward to > investigate and iterate on solutions when loading into jconsole. > > So the scheme I came up with is a simple modification of the initial approach. > Instead of p1, p2, etc. we now have [x1], v1, y1, [x2], v2, y2, etc. (where > [x1] means that x1 is optional). Effectively we want to expand the argument > '1' > into 'x1 v1 y1' or 'v1 y1' as appropriate and then execute. This is how I am > achieving that: > > echo ". ,"_1 ,&' '&> |: (#~"1 (0 3 0) = 4!:0) 'xvy' ,&.>/ ARGV > > It's quite nice how closely this mirrors the original approach. After the > hook, > we have a table whose columns encode the executions we want. Finally, a bit of > munging gives the desired result. > > Thoughts? Is this Good J TM? > ---------------------------------------------------------------------- > For information about J forums see http://www.jsoftware.com/forums.htm ---------------------------------------------------------------------- For information about J forums see http://www.jsoftware.com/forums.htm
