def to_ast
      payload = @string.each_char.with_index.map { |c, i| AST::Node[c == ?/ ? :separator : :char].new(c, start: i, stop: i+1) }
      AST::Node[:root].new(payload, pattern: @string, start: 0, stop: @string.length)
    end
def to_ast
      payload = @string.each_char.with_index.map { |c, i| AST::Node[c == ?/ ? :separator : :char].new(c, start: i, stop: i+1) }
      AST::Node[:root].new(payload, pattern: @string, start: 0, stop: @string.length)
    end
Generates an AST so it's compatible with {Mustermann::AST::Pattern}.
 Not used internally by {Mustermann::Identity}.
 @!visibility private