Dear Community,

We are pleased to announce the availability of the Next Scripting
Framework (NSF) 2.2.0. The changes are mostly performance and
robustness improvements, providing better error messages etc.
See below for the details.


Diff stats since 2.1.0:
 214 files changed, 54192 insertions(+), 44982 deletions(-)


Major changes relative to 2.1.0 are:

New Features

- NSF:

  * Robustness improvements:

    + Use exactly the same six whitespace-delimiter characters in NSF as in
      plain Tcl to avoid surprises (internal API: NsfHasTclSpace())

    + Improved parameter parsing: Don't allow bytearrays as name of
      non-positional arguments, to avoid that bytearrays get unwanted string
      representations (and losing potentially the pure bytearray
      property). This could lead to problems with newer Tcl versions
      when passing binary data to NSF procs and methods.


  * Performance improvements:

    + coloncmd reform: Dispatch performance of [:myMethod ...] is
      improved by up to 30% by caching the result of the method lookup
      in a Tcl_Obj

    + Lookup of (bytecode-compiled) object variables is now
      performed via a sorted lookup cache to avoid repeated linear
      searches for compiled locals (especially an improvement for
      unsuccessful searches).

    + Reduced number of string comparisons (strcmp()) via first-char
      comparison in method-parameter parsing and argument handling.

    + Reduced number of strlen() operations, especially in
      method-parameter parsing and argument handling.

    + Reduced memory consumption via better member aligning of
      structs, esp. on 64-bit machines.


  * New, low-level helper command:

      * "::nsf::definitionnamespace": Determines the default namespace
	for objects etc. as used internally in NSF

	* "::nsf::cmd::info disassemble  /methodName/",
	  "/cls/ info method disassemble /methodName/",
	  "/obj/ info method disassemble /methodName/": This is the
	pendant to ::tcl::unsupported::disassemble adding support for
	NSF methods and NSF procs (nsf::proc). See, e.g.,
	https://wiki.tcl.tk/21445. The "info" methods are only
	available when NSF has been built using --enable-development.

- NX:

  * Improvements to incremental property methods: Adding ("value=add")
    and deleting elements ("value=delete") now enforce any value
    checkers defined on their properties and behave correctly when
    conversion is used.

  * Improvements to handling of parameter option "substdefault".  NX
    provides now controls to the developer to select the kind of
    substitution at runtime when a default value is used.

    + the "substdefault" options can control via a single argument whether
      command/variable/backslash substitution is wanted. Examples:
	  0x111  substitute all
	  0x100  only command substitution
	  0x010  only variable substitution
	  0x001  only backslash substitution
      or any bit combination. Combinations can be used to define the
      equivalents of the flag "-nocommands" (0x011), "-novariables"
      (0x101), "-nobackslashes" (0x110), and their mixes,
      respectively, available to [subst].

     + make behavior of per-object and per-class substdefaults
       consistent, early check for complete substitution scripts.

  * Improvements to ensemble methods:
    + Fixed bug when ensemble method was dispatched via colon dispatcher
      (problem with leading colon)
    + [current nextmethod] + [current isnextcall] return now proper
      ensemble methods when necessary

- MongoDB interface upgrade:

  * Upgraded driver and utilities to mongodb-c-driver 1.12.0 and libbson 1.12.0.
  * Add regular expression queries to conditions in nx::mongo
  * Improved portability between platforms/ OS
  * Added auto-cleanup of resources (objects) for long-living
    execution environments (destroy_on_cleanup).
  * More robust serialization of object graphs, by preserving original
    classes in serialization/deserialization.
  * Fixed default-value handling under certain conditions  

- nx::test:

  * Provide support for expressing expected results in terms of error
    codes, rather than error messages. This is to prepare an upcoming
    reform on providing error codes from within NSF more extensively.

- nx::serializer:

   * Fix potential problem in NaviServer ns_eval with blueprint updates
     on objects, which were not created by the blueprint. Such objects
     could lose their classes when these classes are cleaned up on
     blueprint evaluation.

- DTrace support (macOS): Adjusted NSF/DTrace integration for
  changes on recent macOS (incl. SIP). See dtrace/README for
  instructions.

- Documentation:

  * NSF now has support for TIP #59 introspection via
     ::nsf::pkgconfig; see https://core.tcl.tk/tips/doc/trunk/tip/59.md
  * Added tutorials on NX properties: tutorial-properties.tcl
  * Improved spelling in documentation: next-migration.txt etc.

- Continued testing: NSF is now continuously built and tested under
  Linux, macOS, and Windows against different Tcl targets, using
  different tool chains (gcc, clang, MinGW, MSVC). For this purpose,
  there is now an official GitHub mirror at:

	    https://github.com/nm-wu/nsf

  Build and test reports are available from:

	    https://travis-ci.com/nm-wu/nsf
	    https://ci.appveyor.com/project/mrcalvin/nsf-2ylk0

- Maintenance & bug fixes:

  * Execution namespace reform: As in earlier releases, NSF methods can
    execute in different namespaces such as their object's definition
    namespace.  Starting with NSF 2.2, the execution namespace is
    maintained in a context structure and the namespace is just
    changed while the proc is executing. This fixes some
    counter-intuitive results using standard Tcl introspection on
    these commands.

  * Migration to C type 'bool':
    replace legacy 0/1 integer bools by proper types when possible.

  * Tcl 8.7:

    Support for Tcl 8.7a1 and the upcoming, unreleased Tcl 8.7a2
    (core.tcl.tk branch "core-8-branch"). NSF compiles and its
    regression tests execute successfully.

  * Misc (esp. NSF/C):

    + Bug fix: Avoid preemptive frees on %proc substitution for
      forwarder methods.
    + Aliases: Avoid Tcl_obj re-creations
    + Guarded against potential Tcl_Obj leaks, esp. when using
      "NsfMethodNamePath", as indicated by valgrind.
    + Silenced warnings emitted by GCC 8.1+ on strncat() and strncpy().
    + Addressed 5 code-quality issues as indicated by
      Coverity Scan, incl. control-flow issues (risking NULL
      dereferencing) and buffer overflows in string operations.
    + Silence warnings under MSVC 1914

  * New configure option: "--enable-development=test"
    Enable computationally intensive runtime tests, having
    noticeable effects on runtime. A version of NSF configured with
    "--enable-development" can be used also for production environments.

  * Extended regression test suite:
    The test suite contains now 6243 tests (for Tcl 8.6.8). This
    compares with 5852 tests in NSF 2.1.0 (for Tcl 8.6.6).

- Packaging & distribution:

  * Initial support for the new nmake system of TEA (TIP 477) and MSVC
    1914 (VS 2017; win/makefile.vc); various fixes to install target.

The detailed changelog is available at
https://next-scripting.org/xowiki/download/file/ChangeLog-2.1.0-2.2.0.log

The Next Scripting Framework 2.2.0 (containing NX 2.2.0 and XOTcl
2.2.0) can be obtained from https://next-scripting.org/. Please report
issues and wishes by opening a ticket at
https://sourceforge.net/p/next-scripting/tickets/.

Best regards
- Gustaf Neumann
- Stefan Sobernig