Posted by naruse on 17 Nov 2025
We are pleased to announce the release of Ruby 4.0.0-preview2. Ruby 4.0 updates its Unicode version to 17,0.0, and so on.
Language changes
*nil no longer calls nil.to_a , similar to how **nil does not call nil.to_hash . [[Feature #21047]]
Core classes updates
Note: We’re only listing notable updates of Core class.
Binding Binding#local_variables does no longer include numbered parameters. Also, Binding#local_variable_get and Binding#local_variable_set reject to handle numbered parameters. [[Bug #21049]]
IO IO.select accepts +Float::INFINITY+ as a timeout argument. [[Feature #20610]]
String Update Unicode to Version 17.0.0 and Emoji Version 17.0. [[Feature #19908]][[Feature #20724]][[Feature #21275]] (also applies to Regexp)
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