| # select_multi works around a restriction in native select() that prevents multiple |
| # keys from being matched unless one is a strict subset of another. For some features, |
| # we allow multiple of that component to be active. For example, with codecs, we let |
| # the clients mix and match anywhere from 0 built in codecs to all of them. |
| # |
| # select_multi takes a given map and turns it into several distinct select statements |
| # that have the effect of using any values associated with any active keys. |
| # For example, if the following parameters are passed in: |
| # values_map = { |
| # ":alpha": ["apple", "apricot"], |
| # ":beta": ["banana"], |
| # ":gamma": ["grapefruit"], |
| # }, |
| # default = [] |
| # it will be unrolled into the following select statements |
| # [] + select({ |
| # ":apple": ["apple", "apricot"], |
| # "//conditions:default": [], |
| # }) + select({ |
| # ":beta": ["banana"], |
| # "//conditions:default": [], |
| # }) + select({ |
| # ":gamma": ["grapefruit"], |
| # "//conditions:default": [], |
| # }) |
| def select_multi(values_map, default): |
| if len(values_map) == 0: |
| return default |
| rv = [] |
| for key, value in values_map.items(): |
| rv += select({ |
| key: value, |
| "//conditions:default": default, |
| }) |
| return rv |
