I use alt + '-' for ' <- ' all the time, and I especially love it because it adds the spaces before and after itself.
I know of no shortcut for its left-to-right counterpart, i,e. ' -> '.
Something like shift+alt+'-' seems like a good choice.
My question: Can I create new key shortcuts? I know I can modify existing ones, but I don't know how, or if, I can create new ones.