mailing-list for TeXmacs Users

[Joris van der Hoeven <address@hidden>]

Hi Michael,

On Thu, Jul 12, 2012 at 04:50:21PM +0800, Michael Lachmann wrote:
> 1. The function v() in R will insert the current plot into the buffer.
> It is supposed to support inserting the image using "ps:", and also
> using
> "scheme:(image (tuple (raw-data..."
> and
> "scheme:(image (tuple (# ..."
> 
> I think this used to work at some point. Now, when I send hex data, I
> get the error:
> <error|bad image|<tuple<error|compound
> #XXXX... >|
> png>>
> 
> When I save the file, and reload it, I get a correct figure, though.
> 
> The commands that generate the image are:
> cat("\002scheme:(image (tuple (#",sep="")
> flush(stdout())
> system2("hexdump",args=c("-v","-e","'1/1 
> \"%02X\"'",op$file),stdout=stdout())
> flush(stdout())
> cat(") \"",format,"\") \"0.8par\" \"\" \"\" \"\")\005\n",sep="")
> 
> which are pretty self-explanatory, except that "cat" will print its 
> arguments.
> 
> This should produce:
> \2scheme:(image (tuple (#
> [now the hexdump]
> ) "png") "0.8par" "" "" "")\5
> 
> Do I do something wrong?

If I remember well, then you should rather use the raw-data tag,
if you want to directly use Scheme.

> 2. This is actually a future improvement. But I'd like to be able to
> insert a scheme for a function with its arguments. I.e. when the user
> asks to insert a certain function into the input field, I'd like to
> insert something like
> function.name( argument1=[], argument2=[], .. )
> so that the user can easily traverse between the arguments with the
> left-right keys, i.e. the cursor starts within the [] of argument1,
> and if I hit -> then I get into the [] of argument2, and so on. Is
> something like this possible?

Sure, you can override the behaviour of kbd-right and kbd-left
when you are inside an R session. However, I would not recommend
directly using -> and <- for this purpose, because users will
have difficulties to move outside the brackets when needed.
I rather suggest to overload the tab key to search for
empty brackets [], before trying to do tab completion.
Or use yet another keyboard shortcut for this purpose.

Best wishes, --Joris