## Summary `itblock` node is added to support the `it` block parameter syntax introduced in Ruby 3.4. ```console $ ruby -Ilib -rprism -rprism/translation/parser34 -e 'buffer = Parser::Source::Buffer.new("path"); buffer.source = "proc { it }"; \ p Prism::Translation::Parser34.new.tokenize(buffer)[0]' s(:itblock, s(:send, nil, :proc), :it, s(:lvar, :it)) ``` This node design is similar to the `numblock` node, which was introduced for the numbered parameter syntax in Ruby 2.7. ``` $ ruby -Ilib -rprism -rprism/translation/parser34 -e 'buffer = Parser::Source::Buffer.new("path"); buffer.source = "proc { _1 }"; \ p Prism::Translation::Parser34.new.tokenize(buffer)[0]' s(:numblock, s(:send, nil, :proc), 1, s(:lvar, :_1)) ``` The difference is that while numbered parameters can have multiple parameters, the `it` block parameter syntax allows only a single parameter. In Ruby 3.3, the conventional node prior to the `it` block parameter syntax is returned. ```console $ ruby -Ilib -rprism -rprism/translation/parser33 -e 'buffer = Parser::Source::Buffer.new("path"); buffer.source = "proc { it }"; \ p Prism::Translation::Parser33.new.tokenize(buffer)[0]' s(:block, s(:send, nil, :proc), s(:args), s(:send, nil, :it)) ``` ## Development Note The Parser gem does not yet support the `it` block parameter syntax. This is the first case where Prism's node design precedes that of the Parser gem. When implementing https://github.com/whitequark/parser/issues/962, this node design will need to be taken into consideration. https://github.com/ruby/prism/commit/c141e1420a