Add a static `acorn` property to the `Parser` class that contains the entire module interface, to allow plugins to access the instance of the library that they are acting on.
## 6.3.0 (2019-08-12)
### New features
`sourceType: "module"` can now be used even when `ecmaVersion` is less than 6, to parse module-style code that otherwise conforms to an older standard.
Allow U+2028 and U+2029 in string when ECMAVersion >= 10.
Allow binding-less catch statements when ECMAVersion >= 10.
Add `allowAwaitOutsideFunction` option for parsing top-level `await`.
## 5.5.3 (2018-03-08)
### Bug fixes
A _second_ republish of the code in 5.5.1, this time with yarn, to hopefully get valid timestamps.
## 5.5.2 (2018-03-08)
### Bug fixes
A republish of the code in 5.5.1 in an attempt to solve an issue with the file timestamps in the npm package being 0.
## 5.5.1 (2018-03-06)
### Bug fixes
Fix misleading error message for octal escapes in template strings.
## 5.5.0 (2018-02-27)
### New features
The identifier character categorization is now based on Unicode version 10.
Acorn will now validate the content of regular expressions, including new ES9 features.
## 5.4.0 (2018-02-01)
### Bug fixes
Disallow duplicate or escaped flags on regular expressions.
Disallow octal escapes in strings in strict mode.
### New features
Add support for async iteration.
Add support for object spread and rest.
## 5.3.0 (2017-12-28)
### Bug fixes
Fix parsing of floating point literals with leading zeroes in loose mode.
Allow duplicate property names in object patterns.
Don't allow static class methods named `prototype`.
Disallow async functions directly under `if` or `else`.
Parse right-hand-side of `for`/`of` as an assignment expression.
Stricter parsing of `for`/`in`.
Don't allow unicode escapes in contextual keywords.
### New features
Parsing class members was factored into smaller methods to allow plugins to hook into it.
## 5.2.1 (2017-10-30)
### Bug fixes
Fix a token context corruption bug.
## 5.2.0 (2017-10-30)
### Bug fixes
Fix token context tracking for `class` and `function` in property-name position.
Make sure `%*` isn't parsed as a valid operator.
Allow shorthand properties `get` and `set` to be followed by default values.
Disallow `super` when not in callee or object position.
### New features
Support [`directive` property](https://github.com/estree/estree/compare/b3de58c9997504d6fba04b72f76e6dd1619ee4eb...1da8e603237144f44710360f8feb7a9977e905e0) on directive expression statements.
## 5.1.2 (2017-09-04)
### Bug fixes
Disable parsing of legacy HTML-style comments in modules.
Fix parsing of async methods whose names are keywords.
## 5.1.1 (2017-07-06)
### Bug fixes
Fix problem with disambiguating regexp and division after a class.
## 5.1.0 (2017-07-05)
### Bug fixes
Fix tokenizing of regexps in an object-desctructuring `for`/`of` loop and after `yield`.
Parse zero-prefixed numbers with non-octal digits as decimal.
Allow object/array patterns in rest parameters.
Don't error when `yield` is used as a property name.
Allow `async` as a shorthand object property.
### New features
Implement the [template literal revision proposal](https://github.com/tc39/proposal-template-literal-revision) for ES9.
## 5.0.3 (2017-04-01)
### Bug fixes
Fix spurious duplicate variable definition errors for named functions.
## 5.0.2 (2017-03-30)
### Bug fixes
A binary operator after a parenthesized arrow expression is no longer incorrectly treated as an error.
## 5.0.0 (2017-03-28)
### Bug fixes
Raise an error for duplicated lexical bindings.
Fix spurious error when an assignement expression occurred after a spread expression.
Accept regular expressions after `of` (in `for`/`of`), `yield` (in a generator), and braced arrow functions.
Allow labels in front or `var` declarations, even in strict mode.
### Breaking changes
Parse declarations following `export default` as declaration nodes, not expressions. This means that class and function declarations nodes can now have `null` as their `id`.
## 4.0.11 (2017-02-07)
### Bug fixes
Allow all forms of member expressions to be parenthesized as lvalue.
Solve spurious parenthesized pattern errors by temporarily erring on the side of accepting programs that our delayed errors don't handle correctly yet.