* "dd" isn't reasonable because it violates the "command + movement/region" structure of vi commands. So is "cc" and "yy". None of "c d y" is not a movement or region. Presumably in this editor "_" represents the "whole line" region, which leads to also "c_" and "y_". Much more regular although it does require you to lift your finger one more time.
* "cw" isn't reasonable because "w" as a movement usually means "to the next word", but in "cw" it means "to the end of current word" instead. "ce" is indeed better.
* "r" is actually not bad (indeed "rx" is equivalent to "clx<Esc>", but the former requires 2 keystrokes), but I guess it's because the author rarely uses it.
Anyway the editor is pretty small, it might be easy or even fun to hack it! :)
* "dd" isn't reasonable because it violates the "command + movement/region" structure of vi commands. So is "cc" and "yy". None of "c d y" is not a movement or region. Presumably in this editor "_" represents the "whole line" region, which leads to also "c_" and "y_". Much more regular although it does require you to lift your finger one more time.
* "cw" isn't reasonable because "w" as a movement usually means "to the next word", but in "cw" it means "to the end of current word" instead. "ce" is indeed better.
* "r" is actually not bad (indeed "rx" is equivalent to "clx<Esc>", but the former requires 2 keystrokes), but I guess it's because the author rarely uses it.
Anyway the editor is pretty small, it might be easy or even fun to hack it! :)