RFR 8146138 et. al.: jshell tool: add /help command plus misc fixes

[Jan Lahoda]

Hi Robert,

v2 seems Ok to me.

Jan

On 10.2.2016 02:17, Robert Field wrote:
> New webrev:
>      http://cr.openjdk.java.net/~rfield/8146138v2.webrev/
>
> See below...
>
> On 02/09/16 04:27, Jan Lahoda wrote:
>> Hi Robert,
>>
>> Overall, seems OK to me.
>>
>> Comments:
>> -in the external editor handling, do we need to care about editor
>> commands that have a space in the path? (I.e. is there a need for the
>> user to quote the external editor path?)
>
> Absolutely true, new webrev allows quoting of command and parameters;
> Also, does argument splitting in a cleaner way.
>
>> -I am not quite sure which part of the patch relates to JDK-8147898
>> (/reload quiet)?
>
> It already works (fixed not sure when), all it was missing was a test,
> which this adds.
>
> Note: the new webrev includes tests for 8147886 and 8147887.
>
>> -in JShellTool.cmdHelp(), when the full help is constructed for
>> commands, it always ends with "\n\n", which then produces several
>> empty lines at the end of the help when printed. Would it make sense
>> to strip some of the trailing newlines so that there would be only a
>> single empty line between the help and the prompt?
>
> Yeah, it printed three blank lines -- which is too much.  Tried with
> one, but since help messages are so long, didn't seem enough to see the
> prompt.  Also, starting the command/subject title without blank line
> looks weird.  So, what I've done is rotate one new-line to the top --
> this keeps a two-blank separator between subjects if there are more than
> one.
>
>> -just a note about future - we might provide a completion for /help as
>> well.
>
> True. Added:
>       8149498:jshell tool: command completion on /help <command> and
> <subject>
>
> Thanks Jan!
>
> -Robert
>
>>
>> Jan
>>
>> On 28.1.2016 22:41, Robert Field wrote:
>>> Fixes:
>>>
>>> 8146138 jshell tool: add /help <command>
>>> 8147495 jshell tool: correctly handle arguments on /seteditor command
>>> 8147886 jshell tool: commands don't allow reference to start-up or
>>> explicit id of dropped/failed snippets
>>> 8147887 jshell tool: /list start -- fails
>>> 8147898 jshell tool: /reload quiet -- should quiet echo
>>>
>>> Webrev:
>>>
>>>    http://cr.openjdk.java.net/~rfield/8146138v0.patch/
>>>
>>> Thanks,
>>> Robert
>>>
>