JShell & Newbies

[Ben Evans]

+Anna

On Thu, Sep 22, 2016 at 12:52 PM, Robert Field <robert.field at oracle.com> wrote:
>
> On 09/21/16 23:07, Ben Evans wrote:
>>
>> Some feedback from my wife, who's currently writing some introductory
>> material for absolute beginners in Java (& programming as a whole) -
>> she uses jshell as the very first thing that learners meet and had
>> this to say:
>
>
> Excellent!  Yes, please, Anna & Ben.
>
> When we launched the JShell project we identified three main audiences:
>
> (1) People learning Java (including learning to program for the first time
> using Java)
>
> (2) Learning a new API or language feature
>
> (3) Prototyping
>
> And it appears this is also significant:
>
> (4) Testing
>
> While we have had some feedback from educators, I think other uses have held
> heavier sway.
>
> I'm particularly interested in making it work well for raw beginners.
>
>>> >I really liked in earlier versions where it returned a type as well as a
>>> > result - helps learners get to grips with java as typed language.
>>> >(Also makes it easier for kids who are used to calculators to understand
>>> > why 4/3 returns 1, not 1.333334!)
>
>
> The feedback I got was that users of other REPLs would "laugh at JShell" if
> it stayed as verbose as it was.
>
> So, we tried to hit a middle ground of being expressive but concise.
>
> The good news is (to do that) we made the jshell tool extremely
> configurable.
>
> First level of configuration is that you can set the feedback mode. Either
> with a command:
>
>     /set feedback verbose
>
> or with a command-line switch:
>
>     jshell -v
>
> The "verbose" predefined mode will show the type.
>
> (you can also go the other direction: concise or silent)
>
> The second level of configuration is what enables the first.  You can, at
> fine detail, configure what feedback you get.  See the /set commands:  /help
> /set, /help /set mode, /help /set format, , /help /set feedback
>
> Weird place to find it (until you think about it), but you can see the
> configuration that creates the default modes here:
>
> langtools/src/jdk.jshell/share/classes/jdk/internal/jshell/tool/resources --
> startup.feedback = ...
>
>> If the usage of jshell for beginners is a big aim of the project
>> (something like Swift Playgrounds), Anna & I would be happy to help
>> review features & provide more feedback with that audience in mind.
>
>
> Absolutely!!
>
> Thanks,
> Robert
>