Most could use the each method, but because of the hack used to
disambiguate old- and new-style loops, some had to use vec::each.
(This hack will go away soon.)
Issue #1619
from_maybe => get_with_default
maybe => with_option
may => with_option_do
I know these names are kind of ridiculous, but it's the best I could think of.
Feel free to bikeshed. Closes#2081