How deeply does The Well-Grounded Rubyist, Fourth Edition cover private_instance_methods?

Explains visibility filtering and ancestor inclusion, but does not develop method lookup internals.

Private_instance_methods

As explained in The Well-Grounded Rubyist, Fourth Edition

private_instance_methods is a Ruby Module method that returns the private instance methods available from a class or module, optionally including inherited and included methods.

private_instance_methods is a Ruby Module method for inspecting the private instance methods available through a class or module. Called without an argument, it returns an array that includes methods defined there and methods inherited from ancestor classes or modules. section 5.4.2 section 15.2.3

Use the method-listing family to choose the visibility and scope you want to inspect:

Call MyClass.private_instance_methods to list private instance methods available from MyClass, including inherited and included methods. section 15.2.3
Pass false to restrict the result to private instance methods defined directly in the queried class or module. section 15.2.3
Compare private_instance_methods with public_instance_methods, protected_instance_methods, and instance_methods when investigating method visibility. section 7.7.3 section 15.2.3

Inspecting Kernel’s private toolkit

Run `$ ruby -e 'p Kernel.private_instance_methods.sort'` to print a sorted list of Kernel’s private instance methods. The result includes scripting and general-purpose operations such as require, load, and raise; because Object mixes in Kernel, these methods can be called without an explicit receiver. section 5.4.2

>> String.methods.grep(/methods/).sort
=> [:instance_methods, :methods, :private_instance_methods, 
:private_methods,:protected_instance_methods, :protected_methods,
 :public_instance_methods,:public_methods, :singleton_methods,
 :undefined_instance_methods]

Browse the related class- and object-level method-querying methods, including private_instance_methods, public_instance_methods, protected_instance_methods, and their object-level counterparts. section 15.2.3

How The Well-Grounded Rubyist, Fourth Edition covers it

Cover of The Well-Grounded Rubyist, Fourth Edition

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Related concepts

private memberproduces · A private member is a program element whose direct access is restricted to its defining class, module, file, or other language-defined scope.
instance_methodscontrasts with · instance_methods is a Ruby Module method that returns the public and protected instance methods available from a class or module, optionally including inherited and included methods.
public_instance_methodscontrasts with · public_instance_methods is a Ruby Module method that returns the public instance methods available from a class or module, optionally including inherited and included methods.
protected_instance_methodscontrasts with · protected_instance_methods is a Ruby Module method that returns the protected instance methods available from a class or module, optionally including inherited and included methods.

This explainer was generated by Manning's knowledge graph from the text of The Well-Grounded Rubyist, Fourth Edition. The section links point to the parts of the book it draws on.