mailing-list for TeXmacs Users

[Michael Lachmann <address@hidden>]

Hi,

I just noticed this strange behaviour in TeXmacs.

When text contains folds, then alt-backspace (remove previous field)  
will delete the field BEFORE the fold. Here is an example.

Lets us say I have an R session in TeXmacs, which contains the  
following:

> a=1
> b=2
> c=3
> |

My cursor is where the '|' is. If I hit alt-backspace, the 'c=3' line  
is deleted. Now things look like this:

> a=1
> b=2
> |

Let us say now I add a text field to the 'b=2' line. I go up, hit 'alt- 
right'. A text field is inserted before the b=2 line. I add a text  
comment there. Things now look like this:

> a=1
o This is a comment that explains why b=2
  > b=2
> |

I got back to my original place, at the end.
Now I hit alt-backspace. Instead of deleting the 'b=2' line, or the  
whole 'b=2' block with the comment, now the 'a=2' line is deleted! A  
bit unexpected. We end up with:

o This is a comment that explains why b=2
  > b=2
> |

It often happened to me that I tried deleting a big block, and by the  
time I understood that I actually had hit the alt-backspace key hard  
enough, many lines before the block were deleted without me noticing.  
Or maybe I thought 'strange, before that block was another, identical  
block. Well, lets delete that one, too.' It is very dangerous to  
delete things that the user doesn't see and for which there is no  
visual feedback that something was deleted.

I think that one of the following should happen:
1. Delete nothing. Alt-backspace simply doesn't work in front of a  
folded block.
2. Delete inside the block, the last line, or the block if there is  
only one line.
3. Delete the whole block.

Michael