reduce repeated backslashes

reduce repeated backslashes

[Andreas Roehler]

Hi,

don't know how to replace/reduce repeated backslashes
from inside a string.

Let's assume "abcdef\\\\"

Tried

(replace-regexp-in-string "\\\\" (number-to-string ?\\) "abcdef\\\\" nil t)

which reduces so far, but shows chars as it's numeric value:

--> "abcdef9292"

Any help? Thanks!


Andreas

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Re: reduce repeated backslashes

[Teemu Likonen]

* 2010-02-15 09:40 (+0100), Andreas Roehler wrote:

> don't know how to replace/reduce repeated backslashes from inside a
> string.
>
> Let's assume "abcdef\\\\"

What is the end result you want? I guess:

    (replace-regexp-in-string "\\\\\\\\" "\\" "abcdef\\\\" nil t)
    => "abcdef\\"

There are 8 backslashes in the regexp string because backslash is a meta
character in Lisp strings and also in regexps. 8 backslashes in a regexp
Lisp string means 2 literal backslashes. In the resulting string there
is only one backslash but it is displayed as two "\\" because it's a
printed representation of Lisp string.

Re: reduce repeated backslashes

[Peter Dyballa]

Am 15.02.2010 um 09:40 schrieb Andreas Roehler:

> don't know how to replace/reduce repeated backslashes
> from inside a string.

Replace-string?

--
Mit friedvollen Grüßen

   Pete

A blizzard is when it snows sideways.

Re: reduce repeated backslashes

[Thierry Volpiatto]

Andreas Roehler <andreas.roehler@online.de> writes:

> Hi,
>
> don't know how to replace/reduce repeated backslashes
> from inside a string.
>
> Let's assume "abcdef\\\\"
>
> Tried
>
> (replace-regexp-in-string "\\\\" (number-to-string ?\\) "abcdef\\\\" nil t)
>
> which reduces so far, but shows chars as it's numeric value:
>
> --> "abcdef9292"
>
> Any help? Thanks!

What result do you expect?

`number-to-string' give the string value of a number:

eval:
?\\ ==> 92
(number-to-string ?\\) ==> "92"

`string' will give you the real value of ?char:
eval:
(string ?\\) ==> "\\"

May be a better approach is:(if it is what you expect)

(substring "abcdef\\\\" 0 7)
"abcdef\\"


-- 
Thierry Volpiatto

Re: reduce repeated backslashes

[Thierry Volpiatto]

Thierry Volpiatto <thierry.volpiatto@gmail.com> writes:

> Andreas Roehler <andreas.roehler@online.de> writes:
>
>> Hi,
>>
>> don't know how to replace/reduce repeated backslashes
>> from inside a string.
>>
>> Let's assume "abcdef\\\\"
>>
>> Tried
>>
>> (replace-regexp-in-string "\\\\" (number-to-string ?\\) "abcdef\\\\" nil t)
>>
>> which reduces so far, but shows chars as it's numeric value:
>>
>> --> "abcdef9292"
>>
>> Any help? Thanks!
>
> What result do you expect?
>
> `number-to-string' give the string value of a number:
>
> eval:
> ?\\ ==> 92
> (number-to-string ?\\) ==> "92"
>
> `string' will give you the real value of ?char:
> eval:
> (string ?\\) ==> "\\"
>
> May be a better approach is:(if it is what you expect)
>
> (substring "abcdef\\\\" 0 7)
> "abcdef\\"
However:

(replace-regexp-in-string "\\\\\\\\" (string ?\\) "abcdef\\\\" nil t)
==> "abcde\\"

-- 
Thierry Volpiatto

Re: reduce repeated backslashes

[Andreas Röhler]

Teemu Likonen wrote:
> * 2010-02-15 09:40 (+0100), Andreas Roehler wrote:
> 
>> don't know how to replace/reduce repeated backslashes from inside a
>> string.
>>
>> Let's assume "abcdef\\\\"
> 
> What is the end result you want? I guess:
> 
>     (replace-regexp-in-string "\\\\\\\\" "\\" "abcdef\\\\" nil t)
>     => "abcdef\\"
> 
> There are 8 backslashes in the regexp string because backslash is a meta
> character in Lisp strings and also in regexps. 8 backslashes in a regexp
> Lisp string means 2 literal backslashes. In the resulting string there
> is only one backslash but it is displayed as two "\\" because it's a
> printed representation of Lisp string.
> 

Thanks all!

Andreas