> Do you think by using Opal or RedScript is possible to avoid learning JavaScript?
RedScript essentially supports JS syntax plus Ruby-like syntax, and allows them to be freely mixed, so you probably need to learn JS for RedScript, especially if you ever have to read code that comes from someone else.
Opal is Ruby, but allows inlining JS (using the mechanism regular Ruby uses for inline shell commands, essentially, the JS interpreter is the "system shell") which I suspect is going to be fairly heavily used in Opal projects until there are more Ruby wrappers around JS functions (e.g., DOM-related ones) necessary for even the most basic web work. So, you probably need to know JS to make effective use of Opal for now, though that may not be true forever.
RedScript essentially supports JS syntax plus Ruby-like syntax, and allows them to be freely mixed, so you probably need to learn JS for RedScript, especially if you ever have to read code that comes from someone else.
Opal is Ruby, but allows inlining JS (using the mechanism regular Ruby uses for inline shell commands, essentially, the JS interpreter is the "system shell") which I suspect is going to be fairly heavily used in Opal projects until there are more Ruby wrappers around JS functions (e.g., DOM-related ones) necessary for even the most basic web work. So, you probably need to know JS to make effective use of Opal for now, though that may not be true forever.