eintr: Regexp Review
12.5 Review
===========
Here is a brief summary of some recently introduced functions.
‘while’
Repeatedly evaluate the body of the expression so long as the first
element of the body tests true. Then return ‘nil’. (The
expression is evaluated only for its side effects.)
For example:
(let ((foo 2))
(while (> foo 0)
(insert (format "foo is %d.\n" foo))
(setq foo (1- foo))))
⇒ foo is 2.
foo is 1.
nil
(The ‘insert’ function inserts its arguments at point; the ‘format’
function returns a string formatted from its arguments the way
‘message’ formats its arguments; ‘\n’ produces a new line.)
‘re-search-forward’
Search for a pattern, and if the pattern is found, move point to
rest just after it.
Takes four arguments, like ‘search-forward’:
1. A regular expression that specifies the pattern to search for.
(Remember to put quotation marks around this argument!)
2. Optionally, the limit of the search.
3. Optionally, what to do if the search fails, return ‘nil’ or an
error message.
4. Optionally, how many times to repeat the search; if negative,
the search goes backwards.
‘let*’
Bind some variables locally to particular values, and then evaluate
the remaining arguments, returning the value of the last one.
While binding the local variables, use the local values of
variables bound earlier, if any.
For example:
(let* ((foo 7)
(bar (* 3 foo)))
(message "`bar' is %d." bar))
⇒ ‘bar’ is 21.
‘match-beginning’
Return the position of the start of the text found by the last
regular expression search.
‘looking-at’
Return ‘t’ for true if the text after point matches the argument,
which should be a regular expression.
‘eobp’
Return ‘t’ for true if point is at the end of the accessible part
of a buffer. The end of the accessible part is the end of the
buffer if the buffer is not narrowed; it is the end of the narrowed
part if the buffer is narrowed.
Info Catalog
eintr: forward-paragraph
eintr: Regexp Search
eintr: re-search Exercises