RFR: 8344706: Compiler Implementation of Compact Source Files and Instance Main Methods [v4]

[Stuart Marks]

On Wed, 9 Apr 2025 17:02:52 GMT, Stuart Marks <smarks at openjdk.org> wrote:

>> The readln methods handle malformed-input and unmappable-character errors by dropping, and using a replacement value. So erroneous input doesn't throw IOError with a CharacterCodingException as the cause.
>> 
>> System.in.close() would a be wild thing to do, but a case where readln would throw IOError.
>
> Ah. Does the specification here need to state the policy around malformed input and unmappable characters? (Or, maybe in the class specification.)
> 
> People have ended up in cases where System.in is closed. It can occur when combining use of Scanner to read from System.in and applying the anything-that-you-open-must-be-closed rule, e.g.,
> 
>     try (Scanner sc = new Scanner(System.in)) {
>         String s = sc.nextLine();
>     }
> 
> which is a mistake, but it takes a long time to explain....

I added a clause to the class specification that covers malformed/unmappable byte sequences.

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PR Review Comment: https://git.openjdk.org/jdk/pull/24438#discussion_r2036340667