v1.0 - 2019-09-23

Changes affecting backwards compatibility

• The switch -d:nimBinaryStdFiles does not exist anymore. Instead stdin/stdout/stderr are binary files again. This change only affects Windows.

• On Windows console applications the code-page is set at program startup to UTF-8. Use the new switch -d:nimDontSetUtf8CodePage to disable this feature.

• The language definition and compiler are now stricter about gensym'ed symbols in hygienic templates. See the section in the manual for further details. Use the compiler switch --oldgensym:on for a transition period.

Breaking changes in the standard library

• We removed unicode.Rune16 without any deprecation period as the name was wrong (see the RFC for details) and we didn't find any usage of it in the wild. If you still need it, add this piece of code to your project:

type
  Rune16* = distinct int16

• exportc now uses C instead of C++ mangling with nim cpp, matching behavior of importc, see #10578. Use the new exportcpp to mangle as C++ when using nim cpp.

Breaking changes in the compiler

• A bug allowing int to be implicitly converted to range types of smaller size (e.g range[0'i8..10'i8]) has been fixed.

Library additions

• encodings.getCurrentEncoding now distinguishes between the console's encoding and the OS's encoding. This distinction is only meaningful on Windows.
• Added system.getOsFileHandle which is usually more useful than system.getFileHandle. This distinction is only meaningful on Windows.
• Added a json.parseJsonFragments iterator that can be used to speedup JSON processing substantially when there are JSON fragments separated by whitespace.

Library changes

• Added os.delEnv and nimscript.delEnv. (#11466)

• Enabled Oid usage in hashtables. (#11472)

• Added unsafeColumnAt procs, that return unsafe cstring from InstantRow. (#11647)

• Make public Sha1Digest and Sha1State types and newSha1State, update and finalize procedures from sha1 module. (#11694)

• Added the std/monotimes module which implements monotonic timestamps.

• Consistent error handling of two exec overloads. (#10967)

• Officially the following modules now have an unstable API:

  • std/varints
  • core/allocators
  • core/hotcodereloading
  • asyncstreams
  • base64
  • browsers
  • collections/rtarrays
  • collections/sharedlist
  • collections/sharedtable
  • concurrency/atomics
  • concurrency/cpuload
  • concurrency/threadpool
  • coro
  • endians
  • httpcore
  • parsesql
  • pathnorm
  • reservedmem
  • typetraits

  Every other stdlib module is API stable with respect to version 1.

Language additions

• Inline iterators returning lent T types are now supported, similarly to iterators returning var T:

iterator myitems[T](x: openarray[T]): lent T
iterator mypairs[T](x: openarray[T]): tuple[idx: int, val: lent T]

• Added an importjs pragma that can now be used instead of importcpp and importc to import symbols from JavaScript. importjs for routines always takes a "pattern" for maximum flexibility.

Language changes

• uint64 is now finally a regular ordinal type. This means high(uint64) compiles and yields the correct value.

Tool changes

• The Nim compiler now does not recompile the Nim project via nim c -r if no dependent Nim file changed. This feature can be overridden by the --forceBuild command line option.
• The Nim compiler now warns about unused module imports. You can use a top level {.used.} pragma in the module that you want to be importable without producing this warning.
• The "testament" testing tool's name was changed from tester to testament and is generally available as a tool to run Nim tests automatically.

Compiler changes

• VM can now cast integer type arbitrarily. (#11459)

Bugfixes