Reapply "Merge pull request #46 from byroot/use-forward-send"

[hsbt]

The original PR is #46

@byroot This change failed with https://github.com/ruby/ruby/blob/master/spec/ruby/library/delegate/delegate_class/instance_method_spec.rb#L16

1)
DelegateClass.instance_method returns a method object for protected instance methods of the delegated class ERROR
NoMethodError: protected method 'prot' called for an instance of DelegateSpecs::Simple
/Users/hsbt/Documents/github.com/ruby/ruby/spec/ruby/library/delegate/fixtures/classes.rb:14:in 'DelegateSpecs::Simple#method_missing'
/Users/hsbt/Documents/github.com/ruby/ruby/lib/delegate.rb:430:in 'prot'
/Users/hsbt/Documents/github.com/ruby/ruby/spec/ruby/library/delegate/delegate_class/instance_method_spec.rb:19:in 'Method#call'
/Users/hsbt/Documents/github.com/ruby/ruby/spec/ruby/library/delegate/delegate_class/instance_method_spec.rb:19:in 'block (2 levels) in <top (required)>'
/Users/hsbt/Documents/github.com/ruby/ruby/spec/ruby/library/delegate/delegate_class/instance_method_spec.rb:4:in '<top (required)>'

[Copilot]

Pull request overview

This PR reapplies changes from PR #46 that attempted to optimize method delegation by using class_eval with string interpolation instead of define_method for most methods. The original PR failed due to a test failure where protected methods could not be properly delegated.

Key Changes:

• Methods are partitioned into "normal" (simple identifier names) and "special" (operators and other special syntax) categories
• Normal methods use class_eval for definition, while special methods continue using define_method
• Protected method marking is moved to after all method definitions

---

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[Copilot]

The direct method call syntax __getobj__.#{method}(...) doesn't work for protected methods because it enforces visibility restrictions. When a protected method is called from outside the class context, Ruby raises a NoMethodError. This is the root cause of the test failure mentioned in the PR description.

The previous implementation used __send__ (via delegating_block), which bypasses visibility checks and works correctly for protected methods. The fix should use __send__ instead of direct method calls to maintain the same behavior.

Suggested change

	"def #{method}(...); __getobj__.#{method}(...); end"
	"def #{method}(...); __getobj__.__send__(:#{method}, ...); end"

[Copilot]

The regex pattern /\A[a-zA-Z]\w*[!\?]?\z/ is too restrictive. It requires methods to start with a letter, but Ruby allows method names to start with underscores (e.g., _internal_method). These valid Ruby methods would be incorrectly classified as "special" and handled differently.

The pattern should be /\A[a-zA-Z_]\w*[!\?]?\z/ to also match methods starting with underscores.

Suggested change

	normal, special = instance_methods.partition { |m| m.match?(/\A[a-zA-Z]\w*[!\?]?\z/) }
	normal, special = instance_methods.partition { |m| m.match?(/\A[a-zA-Z_]\w*[!\?]?\z/) }

[Copilot]

The line number argument __LINE__ in class_eval is incorrect. Since multiple method definitions are joined with semicolons on a single line, all methods will appear to be defined on line 430 in stack traces, making debugging difficult.

Additionally, using __LINE__ here will report the line number of the class_eval call itself, not the line where the method definitions actually start (line 412-414). This will cause confusion when debugging errors in delegated methods.

[Copilot]

The generated method definitions are joined with semicolons on a single line, which will make stack traces harder to read and debug. When an error occurs in a delegated method, the backtrace will show all methods as being on the same line.

Consider joining with newlines instead of semicolons to provide clearer stack traces and better debuggability.

[byroot]

Ah indeed. __send__ should be used for protected methods, I can fix that.

[byroot]

I added a regression test and fixed the PR.

[nobu]

Why "normal" methods need to start with an alphabet, e.g., _ is not the case?

[byroot]

It's a mistake _ should be there too. But it's not a big deal, just means they don't benefit from the optimization.