regular_expresions_notes.txt

List of helpful regular expressions (Emacs specific)

.        any character (but newline)
*        previous character or group repeated (0 or more time)
+        previous character or group repeated (1 or more time)
?        previous charater or group repeated (0 or 1 time)
^        start of line
$        end of line
[...]    any character between brackets
[^..]    any character not between brackets
[a-z]    any character between a to Z
\        prevents interpretation of following special character
\|       or 
\w       word constituent [still not understood]
\b       word boundary [still not understood]
\sc      character with c syntax (e.g. \s- for whitespace char) [still not understood]
\( \)    start\end of group [still not understood]
\< \>    start\end of word [still not understood]
\` \'    start\end of buffer [still not understood]
\1       string matched by the first group [still not understood]
\n       string matched by the nth group [still not understood]
\{3\}    previous character or group, repeated 3 times [still not understood]
\{3,\}   previous character or group, repeated 3 or more times [still not understood]
\{3,6\}  previous character or group, repeated 3 to 6 times [still not understood]