Re: What's the doc of replace-regexp-in-string saying ?

Re: What's the doc of replace-regexp-in-string saying ?

[Pascal J. Bourguignon]

Sidney Lambe <sidneylambe@somewhere.invalid> writes:

> On comp.unix.shell, Pascal J. Bourguignon <pjb@informatimago.com>
> wrote:
>
>> Sidney Lambe <sidneylambe@somewhere.invalid> writes:
>>
>>> On comp.unix.shell, bolega <gnuist006@gmail.com> wrote:
>>>
>>>> Hello All,
>>>
>>>
>>> comp.lang.lisp
>>
>> Better news:comp.emacs.help
>>
>
> Ah yes. I am vi (vanilla vi, not vim or elvis...) man myself, and had forgotten that emacs 
> used lisp. 
>
> I actually have never even tried emacs. Every description I've
> read really turns me off.
>
> It's really a textmode integrated desktop environment
> these days, isn't it?

No, it's a TEXT editor, but you are forbidden to type any character, or
read any character.  It only displays 3D animated little animals in a 3D
wonderworld, and you 'edit' your program by pushing those little 3D
animals around and enticing them doing things more or less palatable.

-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.

Re: What's the doc of replace-regexp-in-string saying ?

[Stefan Monnier]

> No, it's a TEXT editor

I beg to differ: Emacs has never been able to edit any text for me:
I've always had to do the editing myself.


        Stefan "still hoping"

Re: What's the doc of replace-regexp-in-string saying ?

[Pascal J. Bourguignon]

Stefan Monnier <monnier@iro.umontreal.ca> writes:

>> No, it's a TEXT editor
>
> I beg to differ: Emacs has never been able to edit any text for me:
> I've always had to do the editing myself.

It's all your fault.  
What are you waiting to write in emacs lisp the AI to do the editing for you?


-- 
__Pascal Bourguignon__                     http://www.informatimago.com/
A bad day in () is better than a good day in {}.

Re: [2nd attempt] What's the doc of replace-regexp-in-string saying ?

[Tassilo Horn]

bolega <gnuist006@gmail.com> writes:

>> In this doc, its not clear what the role of \' is ?

It does basically that what the docs say: it tells the function to
replace only the first or the last match.

,----[ (info "(elisp)Regexp Backslash") ]
| `\`'
|      matches the empty string, but only at the beginning of the buffer
|      or string being matched against.
| 
| `\''
|      matches the empty string, but only at the end of the buffer or
|      string being matched against.
`----

Here are some examples.

--8<---------------cut here---------------start------------->8---
;; Replace all matches
(replace-regexp-in-string "\\(foo\\)" "bar" "foo foo")
==> "bar bar"

;; Replace only the match at the end of the string
(replace-regexp-in-string "\\(foo\\)\\'" "bar" "foo foo")
==> "foo bar"

;; Replace only the match at the beginning of the string
(replace-regexp-in-string "\\`\\(foo\\)" "bar" "foo foo")
==> "bar foo"
--8<---------------cut here---------------end--------------->8---

BTW: A great tool to experiment with functions is the interactive elisp
shell (M-x ielm RET).

Bye,
Tassilo

Re: [2nd attempt] What's the doc of replace-regexp-in-string saying ?

[Orivej Desh]

Bill Marcum <bill@lat.localnet> writes:

> On 2010-11-22, bolega <gnuist006@gmail.com> wrote:
>>
>> On Nov 21, 3:27 pm, bolega <gnuist...@gmail.com> wrote:
>>> Hello All,
>>>
>>> In this doc, its not clear what the role of \' is ?
>>>
>>>
>>> To replace only the first match (if any), make REGEXP match up to \'
>>> and replace a sub-expression, e.g.
>>>   (replace-regexp-in-string "\(foo\).*\'" "bar" " foo foo" nil nil 1)
>>>     => " bar foo"
>>
> This is off topic for comp.unix.shell, but it seems clear to me. If the 
> regexp didn't end with \', it would change " foo foo" to " bar bar".

Since matching is hungry, this is not the case:

     (replace-regexp-in-string "\\(foo\\).*\\'" "bar"
                               " foo foo" nil nil 1)
     " bar foo"

     (replace-regexp-in-string "\\(foo\\).*" "bar"
                               " foo foo" nil nil 1)
     " bar foo"

Moreover, I'm sure bolega has spotted an error in documentation.
Consider this:

     (replace-regexp-in-string "\\(foo\\).*\\'" "bar"
                                "foo foo\n foo foo" nil nil 1)
     "foo foo
      bar foo"

Documentation string assumed that `.' would match a newline.

\' matches an end of a string, unlike $ which matches both an end of a
string and an end of a line).  Without \' or with $ the last regexp
matches twice:

     (replace-regexp-in-string "\\(foo\\).*" "bar"
                                "foo foo\n foo foo" nil nil 1)
     "bar foo
      bar foo"

     (replace-regexp-in-string "\\(foo\\).*$" "bar"
                                "foo foo\n foo foo" nil nil 1)
     "bar foo
      bar foo"