Actually, it'll be called "svn_rangelist_t", since we've already got lots of public "svn_rangelist_...()" functions.
- Julian ----- Original Message ----- > From: Julian Foad <julianf...@btopenworld.com> > To: Subversion Development <dev@subversion.apache.org> > Cc: > Sent: Friday, 27 July 2012, 10:36 > Subject: Heads-up: new typedef 'svn_merge_rangelist_t' > > Heads up: I'm going to add > > typedef apr_array_header_t svn_merge_rangelist_t; > > There's no major impact; it doesn't change anything functionally. > > The rest of the details: > The immediate reason is to improve the debugging experience: I can then make > GDB > display 'rangelist' values in a simple human-readable form, whereas > presently the best it can do is recognize that it is an APR array and display > something like "array of 2 items". > > Beyond that, it makes sense from a coding abstraction point of view: it fills > in > the gap in this hierarchy of types (quoting from svn_mergeinfo.h): > > /** Terminology for data structures that contain mergeinfo. > * > * Subversion commonly uses several data structures to represent > * mergeinfo in RAM: > * > * (a) Strings (@c svn_string_t *) containing "unparsed mergeinfo". > * > * (b) A "rangelist". An array (@c apr_array_header_t *) of > non-overlapping > * merge ranges (@c svn_merge_range_t *), sorted as said by > * @c svn_sort_compare_ranges(). An empty range list is [...]. > * > * (c) @c svn_mergeinfo_t, called "mergeinfo". A hash mapping merge > * source paths (@c const char *, starting with slashes) to > * non-empty rangelist arrays. A @c NULL hash is used to [...]. > * > * (d) @c svn_mergeinfo_catalog_t, called a "mergeinfo catalog". A > hash > * mapping paths (@c const char *) to @c svn_mergeinfo_t. > * > * Both @c svn_mergeinfo_t and @c svn_mergeinfo_catalog_t are just > * typedefs for @c apr_hash_t *; there is no static type-checking, and > * you still use standard @c apr_hash_t functions to interact with > * them. [...] > */ > > typedef apr_hash_t *svn_mergeinfo_t; > typedef apr_hash_t *svn_mergeinfo_catalog_t; > > The new type will be public. Because it's just a typedef, the C API will be > backward-compatible and it won't change the ABI. (Can someone confirm > that?) > > As mentioned in that doc string, using such a typedef doesn't provide any > static type-checking. > > svn_merge_rangelist_t is not going to be a pointer like svn_mergeinfo_t and > svn_mergeinfo_catalog_t are, since that is a poor idiom leading to inability > to > declare a parameter as "pointer to a const rangelist". > > - Julian >
