On Tue, Jun 17, 2014 at 10:30:35AM +0200, Karsten Blees wrote: > Am 12.06.2014 21:12, schrieb Junio C Hamano: > > Karsten Blees <karsten.bl...@gmail.com> writes: > > > >> Am 10.06.2014 12:17, schrieb Heiko Voigt: > >>> The intention of Jonathans critique here was that you do not see what > >>> this parameter does on the callsite. I.e.: > >>> > >>> hashmap_free(&map, 1); > >>> > >>> compared to > >>> > >>> hashmap_free(&map, HASHMAP_FREE_ENTRIES); > >>> > >>> A boolean basically transfers the same information and would not help > >>> the reader here. > >>> > >>> Cheers Heiko > >>> > >>>  http://article.gmane.org/gmane.comp.version-control.git/243917 > >>> > >> > >> There are languages where you can have e.g. 'hashmap_free(..., > >> free_entries: true)'. In C, however, you do not see what a > >> parameter does at the call site. This is a general language > >> feature, reducing redundancy and keeping it short and concise. IMO > >> there's no reason to treat boolean parameters differently. > > > > But given that you are writing in C, is any of that relevant? We do > > want to keep our call-sites readable and understandable, > > But in C, readable and understandable are opposite goals. > 'Understandable' entails long, redundant identifiers, automatically > decreasing readability. The compiler doesn't care about either, so > we could just as well keep the C part short and use plain English > for understandability: > > /* free maps, except file entries (owned by istate->cache) */ > hashmap_free(&istate->name_hash, 0); > hashmap_free(&istate->dir_hash, 1); > > Note that this not only explains what we're doing, but also why. > > > and 1 or > > true would not help, unless (1) you are the one who wrote the > > function and know that 1 means free the entries, or (2) the API is > > so widely used and everybody knows what 1 means free the entries. > > > > or (3) you need to check the function declaration or documentation > anyway, to understand what the non-boolean parameters do. > > E.g. consider this (from remote.c:1186): > > dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag); > > vs. > > dst_value = resolve_ref_unsafe(matched_src->name, sha1, > RESOLVE_REF_UNSAFE_FOR_READING, > &flag); > > That's three lines vs. one, "RESOLVE_REF_UNSAFE_" is completely > redundant with the function name, "FOR_READING" isn't particularly > enlightening either, and you still don't know what the other three > parameters do. IMO this would be much better: > > /* fully resolve matched symref to resolved ref name and sha1 */ > dst_value = resolve_ref_unsafe(matched_src->name, sha1, 1, &flag); > > So veterans highly familiar with the code can stick to the C part > without being distracted by unnecessary line breaks and > SHOUTED_IDENTIFIERS, while everyone else may find the explanation > helpful. > > > As I said, using enums for hashmap_free isn't a problem on its own. > However, the accepted solution for booleans in the git code base > seems to be to use just an int and 0/1. > > For consistency, we could of course change string_list*, > resolve_ref*, index_file_exists etc. as well. > > ...and in turn 'extern int ignore_case' (because it gets passed to > index_file_exists)? > > ...and in turn all other boolean config variables? > > I don't think this would be an improvement, though.
If this is such a controversial change for you I will drop this patch in the next round. I think it would make the callsite more readable without adding much clutter but I am fine with it either way. -- To unsubscribe from this list: send the line "unsubscribe git" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html