antlr4_7: init at 4.7

Includes a more recent version of antlr to nixpkgs. Previous
versions exist already, but version 4 brings many changes
to the generated code and runtime targets.

The install location has been changed from previous versions
of antlr to make use of the set-java-classpath hook, which
is required to make use of both the runtime and the binary.

Also includes the testing rig as a script to allow graphical
inspection of parse trees.

pkgs/development/tools/parsing/antlr/4.7.nix

···
+{stdenv, fetchurl, jre}:
+
+stdenv.mkDerivation rec {
+  name = "antlr-${version}";
+  version = "4.7";
+  src = fetchurl {
+    url ="http://www.antlr.org/download/antlr-${version}-complete.jar";
+    sha256 = "0r08ay63s5aajix5j8j7lf7j7l7wiwdkr112b66nyhkj5f6c72yd";
+  };
+
+  unpackPhase = "true";
+ 
+  installPhase = ''
+    mkdir -p "$out"/{share/java,bin}
+    cp "$src" "$out/share/java/antlr-${version}-complete.jar"
+
+    echo "#! ${stdenv.shell}" >> "$out/bin/antlr"
+    echo "'${jre}/bin/java' -cp '$out/share/java/antlr-${version}-complete.jar:$CLASSPATH' -Xmx500M org.antlr.v4.Tool \"\$@\"" >> "$out/bin/antlr"
+    
+    echo "#! ${stdenv.shell}" >> "$out/bin/grun"
+    echo "'${jre}/bin/java' -cp '$out/share/java/antlr-${version}-complete.jar:$CLASSPATH' org.antlr.v4.gui.TestRig \"\$@\"" >> "$out/bin/grun"
+
+    chmod a+x "$out/bin/antlr" "$out/bin/grun"
+    ln -s "$out/bin/antlr"{,4}
+  '';
+
+  inherit jre;
+
+  meta = with stdenv.lib; {
+    description = "Powerful parser generator";
+    longDescription = ''
+      ANTLR (ANother Tool for Language Recognition) is a powerful parser
+      generator for reading, processing, executing, or translating structured
+      text or binary files. It's widely used to build languages, tools, and
+      frameworks. From a grammar, ANTLR generates a parser that can build and
+      walk parse trees.
+    '';
+    homepage = http://www.antlr.org/;
+    platforms = platforms.linux;
+  };
+}

pkgs/top-level/all-packages.nix

···
   antlr3_5 = callPackage ../development/tools/parsing/antlr/3.5.nix { };
   antlr3 = antlr3_5;
 
+  antlr4_7 = callPackage ../development/tools/parsing/antlr/4.7.nix { };
+  antlr4 = antlr4_7;
+
   ant = apacheAnt;
 
   apacheAnt = callPackage ../development/tools/build-managers/apache-ant { };