N -- new feature -- I may consider using it
B -- breaking change -- I should review my code
N def-expr now returns the symbol of its name instead of nil. N Array#to_h converts an array of key-value pairs into a Hash. N Enumerable#to_h converts a list of key-value pairs into a Hash. N Binding#local_variable_get(symbol) N Exception#cause provides the previous exception which has been caught at where raising the new exception.