Open question: what code pattern you use usually for null safety problem
ddcovery
antoniocabreraperez at gmail.com
Thu Jan 14 18:24:44 UTC 2021
I know there is other threads about null safety and the
"possible" ways to support this in D and so on.
This is only an open question to know what code patterns you
usually use to solve this situation in D:
if(person.father.father.name == "Peter") doSomething();
if(person.father.age > 80 ) doSomething();
knowing that *person*, or its *father* property can be null
i.e.: the incremental null check solution
if(
person !is null &&
person.father !is null &&
person.father.father !is null &&
person.father.father.name == "Peter"
)
{
doSomething();
}
or the "monad" way
[person].
filter!"a !is null".map!"a.father".
filter!"a !is null".map!"a.father".
filter!"a !is null".map!"a.name".
each!( (name) {
if(name == "Peter") doSomething();
});
or, may be, you have some helper function/structs/templates
if( person.d!"father".d!"father".d!"name".get == "Peter" ){
doSomething()
}
if( person.d!"father".d!"age".get(0) > 80 ){
doSomething()
}
or an "xml path" like template
if( person.get!"father.father.name" == "Peter" )
if( person.get!"father.father.name.length"(0) == 5 )
if( person.get!"father.father.age"(0) > 80 )
If it's not a bother, I'd like to know how you usually approach it
Thanks!!!
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