c# - Avoid Null Checking by using lambdas -

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in article avoid null checks replacing finders tellers author gives ruby example avoid null checking, if object returned block run, if not isn't.

 data_source.person(id) |person|   person.phone_number = phone_number   data_source.update_person person end

i'd same thing in c# using lambda function having trouble coming example same type of thing. create object factory accept id number , lambda function?

well don't know ruby , don't understand exact example given, suspect like:

datasource.update(id, person => person.phonenumber = phonenumber);

where datasource.update would:

  • have signature of void update(string id, action<person> updateaction (or possibly return bool indicate whether or not found person)
  • be implemented as:
    • find person given id
    • if doesn't exist, return immediately
    • otherwise, execute given action, , update backing store modified object

or more (and closer original ruby):

datasource.withperson(id, person => {     person.phonenumber = phonenumber;     datasource.updateperson(person); };

personally prefer first form: it's more specific it's trying achieve, may lend better implementation, , it's cleaner in calling code.


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