This proposal will be addressed by introducting native ruby operator
.? as stated by Matz on 21.10.2015.
See discussion here: https://bugs.ruby-lang.org/issues/11034#change-54502
Nil Conditional Operator in Ruby.
This is my approach to create Nil Conditional Operator in Ruby.
This is very simple, and it is merely an experiment, so use it on your own risk.
Nil Conditional Operator is inspired by Null Conditional Operator introduced in C# 6.0.
nil_conditional is gemified and available on RubyGems.
_? method as Nil Conditional Operator.
logger._?.log('some debug information')
# logger is nil logger.foo.bar.car.cow NoMethodError: undefined method `foo` for #<NilClass> # logger is nil logger._?.foo.bar.car.cow => #<NilConditional> # logger is not nil and all corresponding methods exist logger._?.foo.bar.car.cow => "moooo" # logger is not nil but doesn't have warn method logger._?.warn('some warning') => #<NilConditional> # logger is not nil and have warn method, but foo is invalid # - first not nil value returned by receiver in train wreck breaks nil condition logger._?.warn('some warning').foo => NoMethodError: undefined method `foo` # ... but you can use nil conditional again logger._?.warn('some warning')._?.foo => #<NilConditional> # this works also with class methods Object.non_existent_method NoMethodError: undefined method `non_existent_method` for #<Object> Object._?.non_existent_method => #<NilConditional> # NilConditional object is eql to nil Object.new._?.non_existent_method.nil? => true
NilConditional instances always return new NilConditional object if method is missing. Those objects are also
Changes from version with major 1
Previous version used different syntax
Changes from version with major 0
- Previous version didn't support methods with special characters and there was no support for local variables.
- Previous version used trailing
_?as NilConditional operator. Current version uses preceding double underscore character
Feel free to submit ideas via issues and discuss better solution to Nil Conditional Operator in Ruby
This is free software, licensed under MIT License. See LICENSE.txt file.