Concatenations are constructed from reductions.
Publish named character sets.
Combinators can be optional.
Stub in a parser parser.
Extract some characters.
Add the ‘any’ production.
Add the escaped character production.
Add the POSIX class production.
Add the character set production.
Add the literal production.
Add the terminal production.
Containment combinator names exclude ‘[:’ / ‘:]’.
Publish the names of character sets.
Add productions for symbols.
Add productions for whitespace.
Allow newlines around more operators.
Allow disambiguating parentheses.
Add the repetition production.
Add the concatenation production.
Correct the newline production.