Parle pattern matching

• Character representations
• Character classes
• Unicode character classes
• Alternation and repetition
• Anchors
• Grouping

Parle supports regex matching similar to flex. Also supported are the following POSIX character sets:

• [:alnum:]
• [:alpha:]
• [:blank:]
• [:cntrl:]
• [:digit:]
• [:graph:]
• [:lower:]
• [:print:]
• [:punct:]
• [:space:]
• [:upper:]
• [:xdigit:]

The Unicode character classes are currently not enabled by default, pass --enable-parle-utf32 to make them available. A particular encoding can be mapped with a correctly constructed regex. For example, to match the EURO symbol encoded in UTF-8, the regular expression [\xe2][\x82][\xac] can be used. The pattern for an UTF-8 encoded string could be [ -\x7f]{+}[\x80-\xbf]{+}[\xc2-\xdf]{+}[\xe0-\xef]{+}[\xf0-\xff]+.