Re: History changes

[Daniel J Sebald]

On 12/20/2012 04:31 PM, Rik wrote:
> On 12/20/2012 12:19 PM, address@hidden wrote:
> > Message: 2
> > Date: Thu, 20 Dec 2012 14:55:28 -0500
> > From: "John W. Eaton"<address@hidden>
> > To: Ben Abbott<address@hidden>
> > Cc: octave maintainers mailing list<address@hidden>
> > Subject: Re: clumsy patch for h = history (n)
> > Message-ID:<address@hidden>
> > Content-Type: text/plain; charset=us-ascii
> >
> > On 19-Dec-2012, Ben Abbott wrote:
> >
> > | On Dec 19, 2012, at 9:27 PM, John W. Eaton wrote:
> > |
> > |>  On 19-Dec-2012, Ben Abbott wrote:
> > |>
> > |>  | Perhaps the return cell-strings shouldn' t include the indices?
> > |>
> > |>  Oops.  I'm attaching an updated version of the changeset.
> > |>
> > |>  jwe
> > |
> > | This one works for me!
> >
> > OK, I pushed it to savannah.  I'll leave it to someone else to decide
> > whether the doc strings should be updated.
> Yes to documentation.  The coolest new features won't get used if no one
> knows about them.
>
> Also, should we have a sensible default value for N if history is called
> with no input?  Previously, it would display the entire history starting
> from 1.  This could be pages worth of text if you keep the default
> history_size of 1024.  Now, the default is 1 which produces just the last
> command -- which is always history itself.  This is odd.  See sample
> session below.
>
> octave:8>  x = 1
> x =  1
> octave:9>  history
>   1033 history
> octave:10>  history
>   1034 history

I've just tried history.  Doesn't seem very useful to me if only because 
the list starts from oldest the progresses to most recent.  (I've always 
typed code in a "scratch" file and block copied.  Easy to save, easy to 
alter, easy to recall.)  Here is a sample:

octave:1> history
[pages of history information]
 1020 plot(1:50)
 1021 history
 1022 version
 1023 exit
 1024 # Octave 3.7.0+, Thu Dec 20 17:43:34 2012 CST <sebald@>
 1025 history

I would think most recent first is the way to go.  Otherwise one has to 
scan all the way to the end of the list to get the more recent commands.

Also "# Octave 3.7.0+..." is placed in the history buffer when it really 
isn't something the user typed.

I think I once wrote a history feature for a different project and added 
what seemed to me to be much more useful options than the usual simple 
list.  For example, it seems of no use to put numbers next to the 
history unless there is some useful feature that references that number. 
 Say,

octave> history 1020

in this case recalls line 1020 from the history buffer and either 
executes it or places it on the command line for editing.  Tab 
completion within the history buffer would be nice, i.e., type "history 
plo" and tab complete or maybe just return and lists all command 
starting with "plo", ignoring white space.

It isn't the easiest algorithm to do this sort of stuff, I admit.  There 
is buffer order, advancing the display counters so that the same number 
stays with the same command, sorting, etc.  More difficult than one 
would expect.


> I would think a value for N in the range of 10-20 would be a good default

Sure, but again, in my opinion there isn't much use to any of history 
unless it can be utilized a little more than a simple memory aid.  Right 
now, if one pages through the history and finds the desired command, one 
can't highlight the text and copy, so copy-paste doesn't work.  The 
center mouse button for highlight-paste doesn't work because one is in 
the pager, not at the command line.

Dan