aboutsummaryrefslogtreecommitdiff
path: root/libbuild2/algorithm.cxx
diff options
context:
space:
mode:
authorBoris Kolpackov <boris@codesynthesis.com>2024-02-19 10:34:40 +0200
committerBoris Kolpackov <boris@codesynthesis.com>2024-02-19 12:44:32 +0200
commitbed6b6a9170253e010cbffd59202add4edfd1c2b (patch)
treeee33d1ad1f43bfc0966b8f85f7f84ad6272b1e71 /libbuild2/algorithm.cxx
parent70d63c266ffd313c03f6cf68e7080bbcd3c8c064 (diff)
Add string_map buildfile value type
This exposes the std::map<std::string,std::string> type to buildfiles. New functions: $size(<string-map>) $keys(<string-map>) Subscript can be used to lookup a value by key. The result is [null] if there is no value associated with the specified key. For example: map = [string_map] a@1 b@2 c@3 b = ($map[b]) # 2 if ($map[z] == [null]) ... Note that append (+=) is overriding (like std::map::insert_or_assign()) while prepend (=+) is not (like std::map::insert()). In a sense, whatever appears last (from left to right) is kept, which is consistent with what we expect to happen when specifying the same key repeatedly in a literal representation. For example: map = [string_map] a@0 b@2 a@1 # a@1 b@2 map += b@0 c@3 # a@1 b@0 c@3 map =+ b@1 d@4 # a@1 b@0 c@3 d@4 Example of iteration: map = [string_map] a@1 b@2 c@3 for p: $map { k = $first($p) v = $second($p) } While the subscript is mapped to key lookup only, index-based access can be implemented (with a bit of overhead) using the $keys() function: map = [string_map] a@1 b@2 c@3 keys = $keys($m) for i: $integer_sequence(0, $size($keys)) { k = ($keys[$i]) v = ($map[$k]) } Also, this commit changes the naming of other template-based value types (not exposed as buildfile value types) to use C++ template id-like names (e.g., map<string,optional<bool>>).
Diffstat (limited to 'libbuild2/algorithm.cxx')
0 files changed, 0 insertions, 0 deletions