Andrew Gallant dd120a963a Require escaping of [, &, - and ~ in classes.
The escaping of &, - and ~ is only required when the characters are
repeated adjacently, which should be quite rare. Escaping of [ is always
required, unless it appear in the second position of a range.

These rules enable us to add character class sets as described in
UTS#18 RL1.3 in a backward compatible way.
2016-12-30 01:06:18 -05:00
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2016-12-06 17:35:44 -05:00