We've seen some of this kind of stuff in svn_iter.h, and it did not turn out to be useful. The additional concepts needed to learn/keep/use costed more than the incremental benefit.
I find the SVN_ITER_T() and SVN_ARRAY_ITER() macros in your example to be rather inscrutable. Cheers, -g On Thu, Mar 5, 2015 at 6:16 AM, Julian Foad <julianf...@btopenworld.com> wrote: > In http://svn.apache.org/r1664127 (very similar to the attached patch), > I added some array & hash iterators & accessors to the 'move-tracking-2' > branch > so that I could use more compact iteration code ( > http://svn.apache.org/r1664285) > and get an iteration pool 'for free' (http://svn.apache.org/r1664290). > > Is there any interest in using some of this on trunk? > > Here's a summary. > > Array: apr_array_header_t of pointers to objects, with > > - Simpler syntax for operations such as make, get, set, push, pop. > > - no need to specify the element type in these operations > > - The get and set and iteration functions avoid the need to use the > non-type-safe APR_ARRAY_IDX. (It does not assert that the sizeof(type) > matches, let alone (type) itself. Note: When I inserted > "assert(sizeof(type)==array->elt_size)" in APR's version, the > Subversion > test suite still passed, so that's good.) > > - Shallow and deep duplicators for an array of simple or compound > elements. > > Hash table: same as apr_hash_t but always with C-string keys. > > Iteration over an array or a hash shares these features: > > - Convenience prioritized over speed (but still good speed). > > - Easy access to this key and this value as iterator member variables. > > - for an array: it->i and it->val > - for a hash: it->key and it->val (and it->klen for good measure) > > - Templated iterator with parameterized element type. > > - in an iterator declared as "SVN_ITER_T(svn_branch_family_t) *it;", > it->val has type "svn_branch_family_t *" > > - in an iterator declared as "svn_iter_t *it;", > it->val has type "void *" > > - Built-in, managed iterpool as an iterator member variable. > > - just use it->iterpool; it is automatically created/cleared/destroyed > > - Iteration in sorted order (optional). > > - just use "for (SVN_ARRAY_ITER_SORTED(it, array, comparator, pool))" > instead of "for (SVN_ARRAY_ITER(it, array, pool))"; same for a hash > > Usage examples: > > - outer_family->sub_families = apr_array_make(result_pool, 1, sizeof(void > *)); > + outer_family->sub_families = svn_array_make(result_pool); > > - APR_ARRAY_PUSH(outer_family->sub_families, void *) = family; > + SVN_ARRAY_PUSH(outer_family->sub_families) = family; > > { > - apr_array_header_t *sub_families > - = svn_branch_family_get_children(family, scratch_pool); > - int f; > + SVN_ITER_T(svn_branch_family_t) *fi; > > - for (f = 0; f < sub_families->nelts; f++) > + for (SVN_ARRAY_ITER(fi, svn_branch_family_get_children( > + family, scratch_pool), scratch_pool)) > { > - svn_branch_family_t *sub_family > - = APR_ARRAY_IDX(sub_families, f, svn_branch_family_t *); > - > - SVN_ERR(family_list_branch_instances(rev_root, sub_family, > recursive, > + SVN_ERR(family_list_branch_instances(rev_root, fi->val, recursive, > - verbose, scratch_pool)); > - verbose, fi->iterpool)); > } > } > > - Julian >
