CoCoA » CoCoA-5

Consider a buffer containing the following:

1+2;

3+4;

Note that there are 3 empty lines: one at the start, one in the middle, and one at the end.

If I send the whole buffer to CoCoA-5 then it prints out:

3
7

In contrast, if I try sending the lines one at a time, starting on the first (empty) line, then the first empty line causes cocoa5 to produce an empty line and another with a new prompt. The second line is sent fine, and cocoa5-send-line "cleverly" skips over the following empty line to place the cursor at the start of 3+4;.

I think it might be nice to make cocoa5-send-line send nothing to cocoa5 if the current line is empty (or contains only whitespace), and then make it skip to the next non-empty line (i.e. which contains at least one non-whitespace character) or end of buffer.

What do you think?

John Abbott wrote:

Here is another example:
[...]
where the last line does not have a "newline" at the end.
Calling cocoa5-send-line repeatedly will evaluate the last line many times.

I think it would be better if cocoa5-send-line did nothing (other than perhaps "beep") when called with the cursor at the end of the buffer.

I would leave it as it is, I think this is too difficult to deal well:
we would need to separate the case (probably impossible) whether or not it is the first time we call that line ("beep" makes me think it does nothing, but it should execute the line at least once).

Another possibility is to make cocoa5-send-line insert a newline into the buffer if the line (is non-empty and) does not end with one -- the only possible case is the very last line in a file. This just assume that the buffer is modifiable.

Maybe Anna is right: the problem is not that serious, and there appears to be no (easy?) solution which works well in all cases.

I reiterate my suggestion to make cocoa5-send-line send nothing to CoCoA-5 if the line it is on contains only white space. It can simply move forward to the next non-empty line.

Any objections to this idea? (other than "is it worth the effort?")

John Abbott wrote:

I reiterate my suggestion to make cocoa5-send-line send nothing to CoCoA-5 if the line it is on contains only white space. It can simply move forward to the next non-empty line.

No particular objection. But the case you mention should happen only if the user has explicitely placed the cursor in an empty line, because, after sending a line to CoCoA, the cursor is moved automatically to the following non-empty line.