Re: automatic new-line after 80 columns

[B. T. Raven]

Rodrigo Canellas wrote:
> Em Tuesday 17 February 2009 19:21:10 B. T. Raven escreveu:
> > Rodrigo Canellas wrote:
> > > Hi,
> > >
> > > I really can not find how to set 'emacs' to add a new-line when the line reaches the 80th column. 
> > >
> > > In 'ccmode', I set it fot the comments, but I would like to define for C++ code 
> > > as well.
> > >
> > > Can anyone help me?
> > >
> > > Thanks a lot!
> > How does what you want differ from the behavior you see if you type this 
> > in a buffer:
> >
> > C-u 80 C-x f C-u 1 M-x auto-fill-mode
> >
> > ??
> > I think this is a minor mode that works with most programming languages.
> >
> > Ed
>
> I created a file '/var/tmp/t.cpp'.
> Then when I typed 'C-u 80 C-x f', 'emacs' said 'Fill column set to 80 (was 70)'
> And when I typed 'C-u 1 M-x auto-fill-mode', it did not say anything.

You should see the word "Fill" added to the mode line.
> I typed this:
> #include <iostream>
>
>
> void function_very_very_very_big_but_i_mean_really_big ( ) {
>     {
>         {
>             {
>                 {
>                     {
>                         {
>                             {
>                                 {
>                                     {
>                                         {
>                                             {
>                                                 {
>                                                     {
>                                                         {
>                                                             {
>                                                                 object_a = 
> fc_abc( ) ;
>
>
> Here I expected it would change to:
>
> void function_very_very_very_big_but_i_mean_really_big ( ) {
>     {
>         {
>             {
>                 {
>                     {
>                         {
>                             {
>                                 {
>                                     {
>                                         {
>                                             {
>                                                 {
>                                                     {
>                                                         {
>                                                             {
> 								object_a = 
>                                                                       fc_abc( ) ;
>
>
>
> I mean, to respect  the limit of 80 bytes per line, 'emacs' should insert a 
> new-line after the '='.
>
> Any ideas?

I copy-pasted the above into an Emacs buffer, enabled column-mode, and 
didn't see any lines longer than 78 characters. Auto-fill just breaks 
the line automatically at the word boundary at or just before the 
fill-width character.

Type this:

Now is the time for every good man to come to the aid of every good man who
types

and it should have broken before the word "types."

The above works in a lisp buffer but not in a new one I made (junk.cpp). 
Maybe its working depends on c++ syntax. Did you try menu C++ > Toggle > 
Auto newline?