Documentation of Ruby at the level of S-expressions.
Being a non-expert, I understood that Ruby is parsed into something like S-expressions. I am happy that Ruby allows me not to write in sexps. This buys ergonomy (code readability). I am also happy that Ruby allows me to write in sexps and even convert the sexp code to standard Ruby with tools such as Jim Weirich's Sorcerer. However, it seems to me that at the level of sexps, Ruby is underdocumented for us average users. I can only guess what :program, :stmts, :@int, :@float, :@ident etc. in Ripper.sexp output mean. Why not make the Ruby sexp documentation public?