Nim/changelog.md

v0.X.X - XX/XX/2018

Changes affecting backwards compatibility

• The stdlib module future has been renamed to sugar.
• macros.callsite is now deprecated. Since the introduction of varargs parameters this became unnecessary.
• Anonymous tuples with a single element can now be written as (1,) with a trailing comma. The underlying AST is nnkTupleConst(newLit 1) for this example. nnkTupleConstr is a new node kind your macros need to be able to deal with!
• Indexing into a cstring for the JS target is now mapped to charCodeAt.

Breaking changes in the standard library

• re.split for empty regular expressions now yields every character in the string which is what other programming languages chose to do.

• The returned tuple of system.instantiationInfo now has a third field containing the column of the instantiation.

• ``cookies.setCookie` no longer assumes UTC for the expiration date.

• strutils.formatEng does not distinguish between nil and "" strings anymore for its unit parameter. Instead the space is controlled by a new parameter useUnitSpace.

• proc `-`*(a, b: Time): int64 in the times module has changed return type to times.Duration in order to support higher time resolutions. The proc is no longer deprecated.

• posix.Timeval.tv_sec has changed type to posix.Time.

Breaking changes in the compiler

Library additions

• re.split now also supports the maxsplit parameter for consistency with strutils.split.
• Added system.toOpenArray in order to support zero-copy slicing operations. This is currently not yet available for the JavaScript target.
• Added getCurrentDir, findExe, cpDir and mvDir procs to nimscript.
• The times module now supports up to nanosecond time resolution when available.
• Added the type times.Duration for representing fixed durations of time.
• Added the proc times.convert for converting between different time units, e.g days to seconds.

Library changes

• macros.astGenRepr, macros.lispRepr and macros.treeRepr now escapes the content of string literals consistently.
• macros.NimSym and macros.NimIdent is now deprecated in favor of the more general NimNode.
• macros.getImpl now includes the pragmas of types, instead of omitting them.
• macros.hasCustomPragma and macros.getCustomPragmaVal now also support ref and ptr types, pragmas on types and variant fields.
• system.SomeReal is now called SomeFloat for consistency and correctness.

Language additions

• Dot calls combined with explicit generic instantiations can now be written as x.y[:z]. x.y[:z] that is transformed into y[z](x) in the parser.
• func is now an alias for proc {.noSideEffect.}.
• In order to make for loops and iterators more flexible to use Nim now supports so called "for-loop macros". See the manual <manual.html#macros-for-loop-macros>_ for more details.

Language changes

• The importcpp pragma now allows importing the listed fields of generic C++ types. Support for numeric parameters have also been added through the use of static[T] types. (#6415)

• Native C++ exceptions can now be imported with importcpp pragma. Imported exceptions can be raised and caught just like Nim exceptions. More details in language manual.

Tool changes

• jsondoc2 has been renamed jsondoc, similar to how doc2 was renamed doc. The old jsondoc can still be invoked with jsondoc0.

Compiler changes

• The VM's instruction count limit was raised to 1 billion instructions in order to support more complex computations at compile-time.

• Support for hot code reloading has been implemented for the JavaScript target. To use it, compile your code with --hotCodeReloading:on and use a helper library such as LiveReload or BrowserSync.

• A new compiler option --cppCompileToNamespace puts the generated C++ code into the namespace "Nim" in order to avoid naming conflicts with existing C++ code. This is done for all Nim code - internal and exported.

• Added macros.getProjectPath and ospaths.putEnv procs to Nim's virtual machine.

Bugfixes