string-match: \` and \= do not match when START is non-zero

string-match: \` and \= do not match when START is non-zero

[Kevin Rodgers]

\` or \= should match the empty string at index START in STRING.

(string-match "\\`bar\\'" "foobar" 3) and (string-match "\\=bar\\'" "foobar" 3)
return nil.  I think at least one of them should succeed and return 3, just like
(string-match "bar\\'" "foobar" 3) does.  Otherwise, how can you anchor the
REGEXP at index START in STRING?

[time passes]

(equal (string-match REGEXP STRING START) START)

[never mind]
-- 
<a href="mailto:&lt;kevin.rodgers&#64;ihs.com&gt;">Kevin Rodgers</a>

Re: string-match: \` and \= do not match when START is non-zero

[Kevin Rodgers]

I wrote:

> \` or \= should match the empty string at index START in STRING.
> 
> (string-match "\\`bar\\'" "foobar" 3) and (string-match "\\=bar\\'" 
> "foobar" 3)
> return nil.  I think at least one of them should succeed and return 3, 
> just like
> (string-match "bar\\'" "foobar" 3) does.  Otherwise, how can you anchor the
> REGEXP at index START in STRING?
> 
> [time passes]
> 
> (equal (string-match REGEXP STRING START) START)
> 
> [never mind]

Since START can be negative, that should be:

(equal (string-match REGEXP STRING START)
        (if (minusp START)
	   (+ (length STRING) START)
	 START))

I'm studying regex.c to see if I can implement \= matching in strings...

-- 
<a href="mailto:&lt;kevin.rodgers&#64;ihs.com&gt;">Kevin Rodgers</a>