package: anyhow
anyhow’s Result type was migrated into rust_core. Anyhow remains completely standalone, only re-exporting the Result Type from rust_core, but gains compatibility with the rest of the rust_core ecosystem.
In addition to the newly compatible types and extensions, such as Option and the cell library, the Result type got a big upgrade. There will likely be a separate post explaining more when rust_core is officially announced. But the big news I want to mention is the Result type now supports Early Return Key Notation which is a derivative of “Do Notation”.
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void main(){
usingTheEarlyReturnKey();
usingRegularPatternMatching();
}
Result<int,String> usingTheEarlyReturnKey() => Result(($){ // Early Return Key
// Will return here with 'Err("error")'
int x = willAlwaysReturnErr()[$].toInt();
return Ok(x);
});
Result<int,String> usingRegularPatternMatching(){
int x;
switch(willAlwaysReturnErr()){
case Err(:final err):
return Err(err);
case Ok(:final ok):
x = ok.toInt();
}
return Ok(x);
}
Result<double,String> willAlwaysReturnErr() => Err("error");
Enjoy!