Elisp programming 12: Regular Expression 2

Character Type

Reference: http://www.gnu.org/software/emacs/manual/html_node/elisp/Char-Classes.html#Char-Classes

When using the character category, you need to add the upper brackets, such as the string: ABCD 3 AB \ ef

To match the numbers, use the character category.: [: Digit:]

The regular expression is written as follows: "[[: digit:]"

[: Xdigit:] used to match hexadecimal numbers

Forward-sentence command

Run the command: Forward-sentence to find the last position (end of the sentence) of the current sentence. Generally, the sentence is a full stop. question mark? Exclamation point! End. However, these symbols may appear in sentences.

For example, if the following sentence uses the forward-sentence command, you can still find the correct end of the sentence.

Hello, world dr. Mark make.

Emacs also provides the m-e shortcut.

Logic or

| The symbol must also use the \ prefix, so it is written as \ |

For example, the string is ABCD 3 AB \ EF.

The following regular expression can be used to match three sub-strings: AB cd AB.

"AB \ | cd"

The reason \ is restricted by the Emacs string syntax. The previous article has already been introduced.

Matching Group

() The matching group is represented by parentheses, but (and) is a special character. Use \ to indicate that it is not used as a special character. However, "\" is a special character and must be preceded by "\". Do not use it as a special character. Therefore

Is written as: \ (and \\)

For example, the regular "\ (AB \ | cd \)" matches the logic or string above and finds the first substring "ABCD"

For more advanced application Reference documents:

Http://www.gnu.org/software/emacs/manual/html_node/elisp/Regexp-Backslash.html#Regexp-Backslash