Improving spelling correction prompt to generate aliases for future use

Improving spelling correction prompt to generate aliases for future use

[Gwern Branwen]

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'lo everyone.

My desire is this: I have a function, 'typo', which is defined thusly:

 function typo () {
 	(typo_darcs "$@" &); #Subshell to insulate environment
 	alias $1=$2; } #now enable the typo for the current shell.
 function typo_darcs () {
 #So often I make little stupid typos while firing away
 #in the shell. So, I whipped up a quick shell script which
 #reads the two arguments provided, and constructs the appropriate
 #echo command to create an alias that solves that typo.
 	cd; #we need to be in a repository directory, which is ~/ since .ztypos is there
 	echo alias $1='"'$2'"' >> ~/.ztypos; #It goes typo wrong-command right-command
 	tail -n 1 ~/.ztypos & #Verify that .ztypos was written, with the right thing.
 	darcs record --compress --skip-long-comment --all --patch-name=".ztypos: alias $1="$2"" .ztypos; }

It basically makes an alias to fix a typo I've just made. This was very useful in Bash since there was no spelling correction. Now, I've only just recently switched from using Bash to using Zsh, and a little experience with spelling correction has convinced it that it would be excellent if, when I make a typo, I could get correction but also somehow have 'typo' be automatically run.

Looking into it, though, it is not very clear how to do this. I though one could perhaps modify SPROMPT to execute 'typo %R %r', but there doesn't seem to be any escape to run arbitrary shell commands. Precmd() also doesn't seem to work, since I don't see anyway for it to get access to %R, %r, or to know there is a misspelling going on at all. I asked around on #zsh, but no one seemed to really know and someone suggested emailing this list might help.

--
gwern
digicash RRF bemd Beach HRT GSM Blowpipe INR Zen AC

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Re: Improving spelling correction prompt to generate aliases for future use

[Peter Stephenson]

Gwern Branwen wrote:
> Looking into it, though, it is not very clear how to do this. I though
> one could perhaps modify SPROMPT to execute 'typo %R %r', but there
> doesn't seem to be any escape to run arbitrary shell commands.

You could "setopt promptsubst" and have typo output the prompt (as well as
whatever else it's doing) then set

SPROMPT='`typo`'

-- 
Peter Stephenson <p.w.stephenson@ntlworld.com>
Web page now at http://homepage.ntlworld.com/p.w.stephenson/

Re: Improving spelling correction prompt to generate aliases for future use

[Bart Schaefer]

On Oct 21,  7:04pm, Peter Stephenson wrote:
}
} You could "setopt promptsubst" and have typo output the prompt (as
} well as whatever else it's doing)

I don't think that'll do what Gwern is after.  He wants to feed the
results (original and suggested replacement) of spelling correction
to "typo" as command-line arguments.

E.g. he wants to do

	typo ${(%):-%R} ${(%):-%r}

but he can't because prompt substitution in parameters doesn't have
access to the SPROMPT escapes.

The following works for simple commands but not loop constructs or other
compound commands:

accept-line() {
  emulate -L zsh
  local -a words
  words=(${(z)BUFFER})
  typeset -g ACCEPTED_CMD=$words[1]
  zle .accept-line "$@"
}
zle -N accept-line

preexec() {
  emulate -L zsh
  local -a words
  words=(${(z)1})
  if [[ $words[1] != $ACCEPTED_CMD ]]
  then
    typo $ACCEPTED_CMD $words[1]
  fi
}

Re: Improving spelling correction prompt to generate aliases for future use

[Gwern Branwen]

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On 2007.10.21 14:45:11 -0700, Bart Schaefer <schaefer@brasslantern.com> scribbled 0 lines:
> On Oct 21,  7:04pm, Peter Stephenson wrote:
> }
> } You could "setopt promptsubst" and have typo output the prompt (as
> } well as whatever else it's doing)
>
> I don't think that'll do what Gwern is after.  He wants to feed the
> results (original and suggested replacement) of spelling correction
> to "typo" as command-line arguments.
>
> E.g. he wants to do
>
> 	typo ${(%):-%R} ${(%):-%r}
>
> but he can't because prompt substitution in parameters doesn't have
> access to the SPROMPT escapes.

Yes, after quite a bit of frustrated and bemused experimentation I discovered I could only get '%R'/'%r' and not their values (which still amazes me just a little).

> The following works for simple commands but not loop constructs or other
> compound commands:
>
> accept-line() {
>   emulate -L zsh
>   local -a words
>   words=(${(z)BUFFER})
>   typeset -g ACCEPTED_CMD=$words[1]
>   zle .accept-line "$@"
> }
> zle -N accept-line
>
> preexec() {
>   emulate -L zsh
>   local -a words
>   words=(${(z)1})
>   if [[ $words[1] != $ACCEPTED_CMD ]]
>   then
>     typo $ACCEPTED_CMD $words[1]
>   fi
> }

Yes, that seems to work fine! Thanks, I hadn't realized that the pre* commands could be helpful in this case. In fact, this actually seems to be an even better solution compared to running out of the prompt, because a 'typo' in the prompt wouldn't know whether the user had answered yes or no - while this preexec thing has a conditional on just that.

--
gwern
Freeh Abbas warfare V fuses crypto AOL Mexico SNT friends

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