# 1.2 - 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.`. - Global variable `lc` has been removed from sugar.nim. ### 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 '}'. - introduced new procs in `tables.nim`: `OrderedTable.pop`, `CountTable.del`, `CountTable.pop`, `Table.pop` - To `strtabs.nim`, added `StringTable.clear` overload that reuses the existing mode. - Added `sugar.outplace` for turning in-place algorithms like `sort` and `shuffle` into operations that work on a copy of the data and return the mutated copy. As the existing `sorted` does. - Added `sugar.collect` that does comprehension for seq/set/table collections. - Added `sugar.capture` for capturing some local loop variables when creating a closure. This is an enhanced version of `closureScope`. ## 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. - `htmlgen.html` allows `lang` on the `` tag and common valid attributes. ## Language additions - An `align` pragma can now be used for variables and object fields, similar to the `alignas` declaration modifier in C/C++. ## Language changes - Unsigned integer operators have been fixed to allow promotion of the first operand. - Conversions to unsigned integers are unchecked at runtime, imitating earlier Nim versions. The documentation was improved to acknowledge this special case. See https://github.com/nim-lang/RFCs/issues/175 for more details. ### Tool changes ### Compiler changes - JS target indent is all spaces, instead of mixed spaces and tabs, for generated JavaScript. - The Nim compiler now supports the ``--asm`` command option for easier inspection of the produced assembler code. - The Nim compiler now supports a new pragma called ``.localPassc`` to pass specific compiler options to the C(++) backend for the C(++) file that was produced from the current Nim module. ## Bugfixes - The `FD` variant of `selector.unregister` for `ioselector_epoll` and `ioselector_select` now properly handle the `Event.User` select event type.