Re: scripting input methods (was back (batch) translate chars to keyboard events)

[Nick Dokos]

Rustom Mody <rustompmody@gmail.com> wrote:

>     Rustom Mody <rustompmody@gmail.com> wrote:
>     I have some bunch of sanskrit (devanagari) to type.  It would be easiest 
> for me if I could have
>     the
>     English (roman) as well as the sanskrit (devanagari).
>    
>     For example using the devanagari-itrans input method I can write the 
> gayatri mantra using
>    
>     OM bhUrbhuvaH suvaH
>     tatsaviturvarenyam
>     bhargo devasya dhImahi
>     dhiyo yonaH prachodayAt
>    
>     and emacs produces *on the fly* (ie I cant see/edit the above)
>    
>       ॐ भूर्भुवः सुवः
>       तत्सवितुर्वरेण्यम्
>       भर्गो देवस्य धीमहि
>       धियो योनः प्रचोदयात्
>    
>     Can I do it in batch mode? ie write the first in a file and run some 
> command on it to produce
>     the second?
> 
> On Mon, Feb 13, 2012 at 9:45 AM, Nick Dokos <nicholas.dokos@hp.com> wrote:
> 
>     Yup, it can be done, probably in multiple ways but here is one.
>    
>     I saw your question on the python list and did a bit of digging: I came
>     up with a method that probably will work but will require more work to
>     flesh out. The key was that input methods read events one at a time and
>     (from the Elisp manual):
>    
>      -- Function: read-event &optional prompt inherit-input-method seconds
>         This function reads and returns the next event of command input,
>         waiting if necessary until an event is available.  Events can come
>         directly from the user or from a keyboard macro.
>    
>     So if you could get the text to become the body of a keyboard macro,
>     you could change the input method, execute the macro and that would
>     submit the text to the input method as if you had typed it.
>    
>     Trying the theory, I started a keyboard macro, typed in OM and a newline
>     and ended the keyboard macro. I can then switch the input method to
>     devanagari-itrans, execute the macro and presto! I get the proper symbol
>     (at least to my untrained eyes).
>    
>     You can insert the definition of a macro in a buffer (and name it, edit 
> it,
>     save it to a file and load the file later, and execute the macro by name 
> as
>     if it were a function (which it is, strictly speaking). The OM macro above
>     turns out to look like this :
>    
>     (fset 'om
>       (lambda (&optional arg) "Keyboard macro." (interactive "p") 
> (kmacro-exec-ring-item (quote ([79
>     77 return] 0 "%d")) arg)))
> 
>  
> 
>     I would change the python (or whatever) program to produce the whole
>     fset form into a file, then start emacs, load the file, switch input
>     method and execute the macro: M-x om.
>    
>     Nick
> 
> Thanks for your efforts Nick!
> Some questions:
> 1. Why fset? 
> 

That's how emacs stored the definition of the macro: I defined the macro
with C-x ( O M C-x ), named it with C-x C-k n om RET and inserted it in
the buffer with M-x insert-kbd-macro RET om RET. The result was as shown
above.

> I can get the following to work
> 
> (defun om (&optional arg)
>   "Keyboard macro."
>   (interactive "p")
>   (kmacro-exec-ring-item '([79 77 return] 0 "%d") arg))
> 
> so assuming its just a stylistic question. [If not please enlighten]

In some sense, fset is the lower level primitive: defun could be defined
in terms of fset (but not the other way round). But they do roughly the
"same thing": they attach a function to the function cell of a symbol.

> By 'work' I mean after this definition, M-x om inserts ॐ into the buffer if 
> devanagari-itrans is
> active. So far so good
> 
> After that I am a bit stuck:
> 2. kmacro-exec-ring-item has just this much documentation.
> 
> kmacro-exec-ring-item is a compiled Lisp function in `kmacro.el'.
> 
> (kmacro-exec-ring-item ITEM ARG)
> 
> Execute item ITEM from the macro ring.
> 
> Does not take me far :-(
> 

Can't help here.

> 3.  I guess this is really the same as the above question...
> You say
>  
> 
>     So all you need to do is produce that vector of ascii values in there. I
>     wrote a trivial python program to produce the ascii codes of your text
>     and stuffed the output into the vector, reevaluated the fset, and
>     executed the macro with a result that looks suspiciously like the one in
>     your email.
> 
> The python (or elisp) to a text (ASCII-only) string to its ASCII is 1 line:
> 
> >>> def Ascii(str): return [ord(c) for c in str]
> 
> I ran this on my file and got:
> [79, 77, 32, 98, 104, 85, 114, 98, 104, 117, 118, 97, 72, 32, 115, 117, 118, 
> 97, 72, 10, 116, 97,
> 116, 115, 97, 118, 105, 116, 117, 114, 118, 97, 114, 101, 110, 121, 97, 109, 
> 10, 98, 104, 97, 114,
> 103, 111, 32, 100, 101, 118, 97, 115, 121, 97, 32, 100, 104, 73, 109, 97, 
> 104, 105, 10, 100, 104,
> 105, 121, 111, 32, 121, 111, 110, 97, 72, 32, 112, 114, 97, 99, 104, 111, 
> 100, 97, 121, 65, 116, 10]
> 
> Ok so remove the commas, ADD A 'return'  after to last 10 (Whats that??)

The 10 is a RET, so you shouldn't have to add an extra one. 

> And it almost works
> ie I get the devanagari output followed by a elisp error:
> 
> Debugger entered--Lisp error: (void-variable प्रचोदयात्)
>   eval(प्रचोदयात्)
>   eval-last-sexp-1(t)
>   eval-last-sexp(t)
>   eval-print-last-sexp()
>   call-interactively(eval-print-last-sexp nil nil)
>   execute-kbd-macro([79 77 32 98 104 85 114 98 104 117 118 97 72 32 115 117 
> 118 97 72 116 97 116 115
> 97 118 105 116 117 114 118 97 114 101 110 121 97 109 98 104 97 114 103 111 32 
> 100 101 118 97 115 121
> ...] 1 kmacro-loop-setup-function)
>   kmacro-exec-ring-item(([79 77 32 98 104 85 114 98 104 117 118 97 72 32 115 
> 117 118 97 72 116 97
> 116 115 97 118 105 116 117 114 118 97 114 101 110 121 97 109 98 104 97 114 
> 103 111 32 100 101 118 97
> 115 121 ...] 0 "%d") 1)
>   om(1)
>   call-interactively(om t nil)
>   execute-extended-command(nil)
>   call-interactively(execute-extended-command nil nil)
> 
> The प्रचोदयात् is the devanagari of the last line: prachodayAt
> If I remove the 10 (newline?) it seems to work without the elisp error
> 
As you point out in your subsequent post, that's an artifact of lisp-interaction
mode: it does not happen in a text file.

> I guess the problem would be solved if some more suitable function than
> I wonder if there is some better function than kmacro-exec-ring-item could be 
> found for this?
> 

And you seem to have found one of those as well.

Good luck!

Nick