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GNU Info (emacs-lisp-intro.info)fwd-sentence re-searchThe regular expression search ----------------------------- The `re-search-forward' function searches for the end of the sentence, that is, for the pattern defined by the `sentence-end' regular expression. If the pattern is found--if the end of the sentence is found--then the `re-search-forward' function does two things: 1. The `re-search-forward' function carries out a side effect, which is to move point to the end of the occurrence found. 2. The `re-search-forward' function returns a value of true. This is the value received by the `if', and means that the search was successful. The side effect, the movement of point, is completed before the `if' function is handed the value returned by the successful conclusion of the search. When the `if' function receives the value of true from a successful call to `re-search-forward', the `if' evaluates the then-part, which is the expression `(skip-chars-backward " \t\n")'. This expression moves backwards over any blank spaces, tabs or carriage returns until a printed character is found and then leaves point after the character. Since point has already been moved to the end of the pattern that marks the end of the sentence, this action leaves point right after the closing printed character of the sentence, which is usually a period. On the other hand, if the `re-search-forward' function fails to find a pattern marking the end of the sentence, the function returns false. The false then causes the `if' to evaluate its third argument, which is `(goto-char par-end)': it moves point to the end of the paragraph. Regular expression searches are exceptionally useful and the pattern illustrated by `re-search-forward', in which the search is the test of an `if' expression, is handy. You will see or write code incorporating this pattern often. automatically generated by info2www version 1.2.2.9 |