mode), it sets the region around the symbol surrounding that character.
If you click on a character with open-parenthesis or close-parenthesis
-syntax, it sets the region around the parenthetical grouping (sexp)
+syntax, it sets the region around the parenthetical grouping
which that character starts or ends. If you click on a character with
string-delimiter syntax (such as a singlequote or doublequote in C), it
sets the region around the string constant (using heuristics to figure