Word description Returns a parser that matches a single character based on the set of characters in the pattern string. Any single character in the pattern matches that character. If the pattern begins with a ^ then the set is negated (the element matches any character not in the set). Any pair of characters separated with a dash (-) represents the range of characters from the first to the second, inclusive.
USING: peg peg.parsers prettyprint strings ;
"a" "_a-zA-Z" range-pattern parse 1string . "a"