Problem using search-forward

Problem using search-forward

[Bob Shanley]

stringToFind("this is a string");
; Given the above string and point positioned at the beginning of the line
; I want to move point to right after the ";" 
; These work:
;   (search-forward ");")
;   (let ( (n 34) ) (search-forward ");" n))
; These do not:
;   (defun eol ( ) (end-of-line) (point))
;   (search-forward ");" (eol))
;   (let ( (n (eol)) ) (message "this is the value %d" n) (search-forward ");" n))
; They result in a Search failed: ");" and point moves to end of line
; What am I missing?
;
Thanks for the help

Re: Problem using search-forward

[Tassilo Horn]

Bob Shanley <rjshanley18@gmail.com> writes:

Hi Bob,

> ; These do not:
> ;   (defun eol ( ) (end-of-line) (point))
> ;   (search-forward ");" (eol))
> ;   (let ( (n (eol)) ) (message "this is the value %d" n) (search-forward ");" n))
> ; They result in a Search failed: ");" and point moves to end of line
> ; What am I missing?

The `end-of-line' call already moves point to the end of line, thus you
bound the search to the same position where it starts.  Try this
definition of `eol'.

  (defun eol ()
    (save-excursion
     (end-of-line)
     (point)))

,----[ C-h f save-excursion RET ]
| save-excursion is a special form in `C source code'.
| 
| (save-excursion &rest BODY)
| 
| Save point, mark, and current buffer; execute BODY; restore those things.
| Executes BODY just like `progn'.
| The values of point, mark and the current buffer are restored
| even in case of abnormal exit (throw or error).
| The state of activation of the mark is also restored.
| 
| This construct does not save `deactivate-mark', and therefore
| functions that change the buffer will still cause deactivation
| of the mark at the end of the command.  To prevent that, bind
| `deactivate-mark' with `let'.
| 
| If you only want to save the current buffer but not point nor mark,
| then just use `save-current-buffer', or even `with-current-buffer'.
`----

Bye,
Tassilo

Re: Problem using search-forward

[Eric Abrahamsen]

On Mon, Oct 08 2012, Tassilo Horn wrote:

> Bob Shanley <rjshanley18@gmail.com> writes:
>
> Hi Bob,
>
>> ; These do not:
>> ;   (defun eol ( ) (end-of-line) (point))
>> ;   (search-forward ");" (eol))
>> ;   (let ( (n (eol)) ) (message "this is the value %d" n) (search-forward ");" n))
>> ; They result in a Search failed: ");" and point moves to end of line
>> ; What am I missing?
>
> The `end-of-line' call already moves point to the end of line, thus you
> bound the search to the same position where it starts.  Try this
> definition of `eol'.
>
>   (defun eol ()
>     (save-excursion
>      (end-of-line)
>      (point)))

I may be missing something here, but isn't this what (point-at-eol) does?

> ,----[ C-h f save-excursion RET ]
> | save-excursion is a special form in `C source code'.
> | 
> | (save-excursion &rest BODY)
> | 
> | Save point, mark, and current buffer; execute BODY; restore those things.
> | Executes BODY just like `progn'.
> | The values of point, mark and the current buffer are restored
> | even in case of abnormal exit (throw or error).
> | The state of activation of the mark is also restored.
> | 
> | This construct does not save `deactivate-mark', and therefore
> | functions that change the buffer will still cause deactivation
> | of the mark at the end of the command.  To prevent that, bind
> | `deactivate-mark' with `let'.
> | 
> | If you only want to save the current buffer but not point nor mark,
> | then just use `save-current-buffer', or even `with-current-buffer'.
> `----
>
> Bye,
> Tassilo
>
>
>

-- 
GNU Emacs 24.2.50.1 (i686-pc-linux-gnu, GTK+ Version 3.4.4)
 of 2012-10-03 on pellet