ANTLR version 4.7 is a major release with many improvements and bug fixes.

Summary of new features, improvements, fixes

The primary improvement is that ANTLR and all code generation targets can now handle full 21-bit unicode thanks to the superhuman effort of Ben Hamilton, @bhamiltoncx. After much thought concerning the "create stream" interface, I have decided on the following end result: C++, Python, Go, and Swift APIs didn't need any changes to support full Unicode code points, so I decided to leave those alone. Java, C#, and JavaScript runtimes required changes. Rather than gutting and changing the interface of the previous ANTLRFileStream etc..., I have deprecated those and introduced a CharStreams.fromXXX factory style interface for creating streams. For example, CharStreams.fromFileName("foo.txt")). See the new unicode documentation and a complete list of all pull requests related to Unicode.
UnbufferedCharStream for Java and C# targets was upgraded to use UTF-8 rather than the locale default encoding; they further support U+10FFFF Unicode code points. C++ is the only other target with the unbuffered stream and it worked as-is.
- Change UnbufferedCharStream to use code points
- Use UTF-8 by default in UnbufferedCharStream and allow specifying charset
- C#: Change UnbufferedCharStream to use 32-bit Unicode code points and 32-bit buffer
In addition to creating CharStreams capable of supporting 21-bit Unicode, we added notation for Unicode code points beyond 16 bits (4 hexadecimal digits). The usual notation \uABCD still works for the basic code points but you can now use \u{1FFFF}..\u{10FFFF} to access the full range:
- New extended Unicode escape \u{10ABCD} to support Unicode literals > U+FFFF
- Support UTF-32 escape sequences
You can also include all characters matching Unicode properties such as [\p{Emoji}]:
The C# target now supports .NET Core Support, thanks to David Neumann @lecode-official and Dong Xie @xied75!
We did quite a bit of cleaning up in the lexer escape char and char set areas (big thanks to Ivan Kochurkin @KvanTTT):
The Go runtime was significantly speeded up.
- Go Runtime: Murmur Hash and various optimizations
- Initialize decisionToDFA in init in Go.stg
The XPath tree matching library used an ANTLR grammar itself, which caused a cyclic dependency in the build whereby ANTLR version v was required to build version v. I implemented a handbuilt lexer to get rid of this dependency on a grammar: XPathLexer not updated in release process, Fixes #1620. Make handbuilt lexer to avoid cyclic dependence of tool and plugin.
The Java, Swift, and C++ targets have added a hook to the construction of parse tree leaf nodes: factor out the creation of error nodes and terminal nodes in the parser. Code new TerminalNodeImpl(..) and new ErrorNodeImpl(...) instead now calls a few factory methods in the Parser that you can override in your application.

Issues fixed

C++ target:

SIGABRT when using TokenStreamRewrite::Delete method
Cpp runtime: compile needed header
compilation warning
Segmentation fault on TokenStreamRewriter destructor call
Runtime build failure on gcc 6.3.1
Fixed regression introduced by wrong optimization. Fixes #1708. (target:cpp)
Fixed crash with multi threaded parsers warming up at the same time. (target:cpp)
Improve error message in exceptions (target:cpp)
Using new Unicode syntax for C++ demo project. (target:cpp, unicode)
Fix syntaxError prototype issue (target:cpp)
Fixed a number of data type + signedness issues in the C++ target (target:cpp)
Some compilers need the functional include. (target:cpp)
Fix wrong include path of antlr4cpp runtime in cmake/ExternalAntlr4Cpp.cmake (target:cpp)
Fix parse tree property (target:cpp)
No static libs anymore for Windows C++ runtime. (comp:build, target:cpp)
Lr loop fix (target:cpp, type:improvement)
adapt code to compile with msys2 mingw compiler (comp:build, target:cpp, type:improvement)
Fix for VS 2013 runtime builds (C++) (comp:doc, target:cpp)
Implemented enhanced CommonToken::toString method
Using new Unicode syntax for C++ demo project. (target:cpp, unicode)
fix an issue where loading antlr from an IE web worker would fail (target:javascript)
Issue 1483 (target:cpp, type:improvement)

JavaScript target:

Python2/3:

C#:

Go:

Java:

Swift:

Remove generated files from repository and add testRig for Swift target (target:swift)
Tweak Repo to use SwiftPackageManager. (target:swift)

Tool or all-target-runtime related:

antlr/antlr4 4.7 on GitHub

Summary of new features, improvements, fixes

Issues fixed

antlr/antlr4 4.7
on GitHub