Roll Observatory packages and add a roll script

petitparser/lib/src/lisp/grammar.dart

-part of lisp;
-
-/**
- * LISP grammar.
- */
-class LispGrammar extends GrammarParser {
-  LispGrammar() : super(new LispGrammarDefinition());
-}
-
-/**
- * LISP grammar definition.
- */
-class LispGrammarDefinition extends GrammarDefinition {
-
-  start() => ref(atom).star().end();
-
-  atom() => ref(atom_).trim(ref(space));
-  atom_() => ref(list)
-      | ref(number)
-      | ref(string)
-      | ref(symbol)
-      | ref(quote)
-      | ref(quasiquote)
-      | ref(unquote)
-      | ref(splice);
-
-  list() => ref(bracket, '()', ref(cells))
-      | ref(bracket, '[]', ref(cells))
-      | ref(bracket, '{}', ref(cells));
-  cells() => ref(cell)
-      | ref(empty);
-  cell() => ref(atom) & ref(cells);
-  empty() => ref(space).star();
-
-  number() => ref(number_).flatten();
-  number_() => anyIn('-+').optional()
-      & char('0').or(digit().plus())
-      & char('.').seq(digit().plus()).optional()
-      & anyIn('eE').seq(anyIn('-+').optional()).seq(digit().plus()).optional();
-
-  string() => ref(bracket, '""', ref(character).star());
-  character() => ref(characterEscape) | ref(characterRaw);
-  characterEscape() => char('\\') & any();
-  characterRaw() => pattern('^"');
-
-  symbol() => ref(symbol_).flatten();
-  symbol_() => pattern('a-zA-Z!#\$%&*/:<=>?@\\^_|~+-')
-      & pattern('a-zA-Z0-9!#\$%&*/:<=>?@\\^_|~+-').star();
-
-  quote() => char('\'') & ref(list);
-  quasiquote() => char('`') & ref(list);
-  unquote() => char(',') & ref(list);
-  splice() => char('@') & ref(list);
-
-  space() => whitespace() | ref(comment);
-  comment() => char(';') & Token.newlineParser().neg().star();
-  bracket(String brackets, Parser parser) => char(brackets[0]) & parser & char(brackets[1]);
-
-}