2018-01-31 18:32 GMT+01:00 Jelle Licht <[email protected]>: > Hi Ludo', > > > 2018-01-27 17:09 GMT+01:00 Ludovic Courtès <[email protected]>: > >> Hello! >> >> Jelle Licht <[email protected]> skribis: >> >> > I noticed that there are currently two very similar functions for >> fetching >> > json data; `json-fetch' in (guix import json) and `json-fetch*' in (guix >> > import github). >> > >> > Some things I noticed: >> > - Dealing with http error codes seems to be a bit more robust in >> > `json-fetch*'. >> > - Making sure that (compliant) servers give responses in the proper >> format >> > seems more robust in `json-fetch' due to using Accept headers. >> > - Dealing with the fact that json responses are technically allowed to >> be >> > lists of objects, which `json-fetch' does not handle gracefully. >> > >> > For this issue specifically, would it make sense to combine the two >> > definitions into a more general one? >> >> Definitely, we should just keep one. It’s not even clear how we ended >> up with the second one. >> > > I even had a third one in my local tree which happened to have a conflict, > which > is how I found out in the first place, so I understand how these things > can happen. > >> >> > My more general concern would be on how we can prevent bug fixes only >> being >> > applied to one of several nearly identical functions. IOW, should we >> try to >> > prevent situations like this from arising, or is it okay if we somehow >> make >> > sure that fixes should be applied to both locations? >> >> We should prevent such situations from arising, and I think we do. >> >> The difficulty is that avoiding duplication requires knowing the whole >> code base well enough. Sometimes you just don’t know that a utility >> function is available so you end up writing your own, and maybe the >> reviewers don’t notice either and it goes through; or sometimes you need >> a slightly different version so you duplicate the function instead of >> generalizing it. >> >> Anyway, when we find occurrences of this pattern, we should fix them! >> > > I basically added the robust features of `json-fetch*' to the exported > `json-fetch' > instead, and all existing functionality seems to work out as far as I can > see. > > I did notice that I now produce hash-tables by default, and some of the > existing usages of `json-fetch*' expect an alist instead. What would be a > guile- > appropriate way of dealing with this? I currently have multiple > `(hash-table->alist (json-fetch <...>))' littered in my patch which seems > suboptimal, > but always converting the parsed json into an alist seems like it might > also not be > what we want. >
of course I' d wait for a thought by some more competent guiler, but I' d like to offer my take on this The new function could take one further argument, a boolean If the boolean is true, it could return a hash table Otherwise, it could return a list If the majority of call sites expect a list, the further argument could set to false as default So you' d only have to fix those call sites that want a hash table instead If, instead, the majority of call sites want a hash table, your procedure would return a hash table by default and a list by a further argument, so you' d have to fix a minority of call sites anyway I hope I didn' t make myself a fool :-/ > Thanks, > Ludo’. > > - Jelle >
