UI review: jshell commands

[Paul Sandoz]

On Jun 30, 2015, at 2:02 AM, Brian Goetz <brian.goetz at Oracle.COM> wrote:

> Now that you have whacked us over the head with "hey, you guys are looking in the wrong direction", I tend to agree.  In fact, that the elements of /list show up starting with 9 is also weird.
> 

Yes, and it's not constant.


> So, how about reflecting this more directly; have the "startup IDs" start at something like auto.1 or startup.1, and then flip over to 1 when we finish with startup.  Then /list would start with 1; /list all would look like:
> 
>  auto.1: import ...
>  auto.2: import
>  1: 1 + 1
> 

I like that approach.

Paul.

> The only important reason that we even need an ID for the startup entries is so we can /drop it.  Having an ID of the form "auto.1" works fine for that.  There's no reason ID has to be an int, is there?
> 
>> Otherwise, the intermediate results of the startup file should be
>> dropped.  Or at least they should not interfere with the auto-generated
>> names for interactive results.
>> 
>> Two compromises possible on that:
>> 
>> 1. If for some reason we must, auto-generate a different set of names
>> for the startup file, starting with $_ (think, "negative") or $0:
>> 
>> 1+1;
>> $1 = 2;
>> $_1;  // host id from startup, etc.
>> 
>> 2. If you buy my argument that auto-generated things are usually
>> useless, have an opt-in argument for those special times when you need
>> auto-numbering of the file.  Replaying a previous interactive input is
>> really a different use case from reusing a common profile.
>> 
>> Such a special time would be replaying scripts, but I can't think of any
>> other.  Perhaps that is envisioned as the default.  In that case, we
>> should be sure that it in the *other default*, when pulling from a
>> startup file like ~/.kullarc, it should be easy to suppress the creation
>> of $N variables.
>> 
>> — John