path: root/changelog.md

# x.x - xxxx-xx-xx


## Changes affecting backwards compatibility



### Breaking changes in the standard library

- `base64.encode` no longer supports `lineLen` and `newLine`.
  Use `base64.encodeMIME` instead.
- `os.splitPath()` behavior synchronized with `os.splitFile()` to return "/"
   as the dir component of "/root_sub_dir" instead of the empty string.
- `sequtils.zip` now returns a sequence of anonymous tuples i.e. those tuples
  now do not have fields named "a" and "b".
- `strutils.formatFloat` with `precision = 0` has the same behavior in all
  backends, and it is compatible with Python's behavior,
  e.g. `formatFloat(3.14159, precision = 0)` is now `3`, not `3.`.


### Breaking changes in the compiler

- Implicit conversions for `const` behave correctly now, meaning that code like
  `const SOMECONST = 0.int; procThatTakesInt32(SOMECONST)` will be illegal now.
  Simply write `const SOMECONST = 0` instead.



## Library additions

- `macros.newLit` now works for ref object types.
- `system.writeFile` has been overloaded to also support `openarray[byte]`.
- Added overloaded `strformat.fmt` macro that use specified characters as
  delimiter instead of '{' and '}'.



## Library changes

- `asyncdispatch.drain` now properly takes into account `selector.hasPendingOperations`
  and only returns once all pending async operations are guaranteed to have completed.
- `asyncdispatch.drain` now consistently uses the passed timeout value for all
  iterations of the event loop, and not just the first iteration.
  This is more consistent with the other asyncdispatch apis, and allows
  `asyncdispatch.drain` to be more efficient.
- `base64.encode` and `base64.decode` was made faster by about 50%.
- `htmlgen` adds [MathML](https://wikipedia.org/wiki/MathML) support
  (ISO 40314).
- `macros.eqIdent` is now invariant to export markers and backtick quotes.



## Language additions



## Language changes

- Unsigned integer operators have been fixed to allow promotion of the first operand.


### Tool changes



### Compiler changes

- JS target indent is all spaces, instead of mixed spaces and tabs, for
  generated JavaScript.



## Bugfixes

- The `FD` variant of `selector.unregister` for `ioselector_epoll` and
  `ioselector_select` now properly handle the `Event.User` select event type.