Re: Regular expression functions (Was: Re: comments on

> To give you an idea about what I'm going on about, the signature of
> the function I have in mind is:


the system which I use to read the email on this list, and to write xsl
stylesheets,  provides the following functions:

==================================================================
match-data is a built-in function.

Return a list containing all info on what the last search matched.
Element 2N is `(match-beginning N)'; element 2N + 1 is `(match-end N)'.
All the elements are markers or nil (nil if the Nth pair didn't match)
if the last match was on a buffer; integers or nil if a string was matched.
Use `store-match-data' to reinstate the data in this list.

If INTEGERS (the optional first argument) is non-nil, always use integers
(rather than markers) to represent buffer positions.
If REUSE is a list, reuse it as part of the value.  If REUSE is long enough
to hold all the values, and if INTEGERS is non-nil, no consing is done.

(match-data &optional INTEGERS REUSE)

==================================================================
match-string is a compiled Lisp function in `subr'.
(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.
==================================================================

match-beginning is a built-in function.

Return position of start of text matched by last search.
SUBEXP, a number, specifies which parenthesized expression in the last
  regexp.
Value is nil if SUBEXPth pair didn't match, or there were less than
  SUBEXP pairs.
Zero means the entire text matched by the whole regexp or whole string.

(match-beginning SUBEXP)
==================================================================
match-end is a built-in function.

Return position of end of text matched by last search.
SUBEXP, a number, specifies which parenthesized expression in the last
  regexp.
Value is nil if SUBEXPth pair didn't match, or there were less than
  SUBEXP pairs.
Zero means the entire text matched by the whole regexp or whole string.

(match-end SUBEXP)

==================================================================


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