string-match and match-string

string-match and match-string

[Lennart Borgman (gmail)]

I get an error when doing things like these:

   (when (string-match "\\(some\\)" "<something>")
     (match-string 1))

   (when (string-match "<.*>" "<something>")
     (match-string 0))

Should not match-string work here?

Note: I am still using a CVS Emacs from June 2007.

Re: string-match and match-string

[Bastien]

"Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:

> I get an error when doing things like these:
>
>   (when (string-match "\\(some\\)" "<something>")
>     (match-string 1))
>
>   (when (string-match "<.*>" "<something>")
>     (match-string 0))
>
> Should not match-string work here?

Use this instead:

(when (string-match "\\(some\\)" "<something>")
  (match-string 1 "<something>"))

(when (string-match "<.*>" "<something>")
  (match-string 0 "<something>"))

,----[ C-h f match-string ]
| match-string is a compiled Lisp function in `subr.el'.
| (match-string num &optional string)
| 
| Return string of text matched by last search.
| num specifies which parenthesized expression in the last regexp.
|  Value is nil if numth pair didn't match, or there were less than num pairs.
| Zero means the entire text matched by the whole regexp or whole string.
| string should be given if the last search was by `string-match' on string.
`----

The relevant part: "string should be given if the last search was by
`string-match' on string."

-- 
Bastien

Re: string-match and match-string

[Lennart Borgman (gmail)]

Bastien wrote:
> "Lennart Borgman (gmail)" <lennart.borgman@gmail.com> writes:
> 
>> I get an error when doing things like these:
>>
>>   (when (string-match "\\(some\\)" "<something>")
>>     (match-string 1))
>>
>>   (when (string-match "<.*>" "<something>")
>>     (match-string 0))
>>
>> Should not match-string work here?
> 
> Use this instead:
> 
> (when (string-match "\\(some\\)" "<something>")
>   (match-string 1 "<something>"))
> 
> (when (string-match "<.*>" "<something>")
>   (match-string 0 "<something>"))


Eh, yes. Thanks.