JavaScriptParser class missing?

[JMCTO]

Hi all, I'm trying to build a Javascript parser in C# VS 2019

At a high level, I see that there is code in the C# directory which does some work. Do I still need to process the .g4 files into code?\

Also, This class is missing:

using static JavaScriptParser;

where can I find that reference ?

I've got antlr4.runtime installed via nuget

thanks

John Mott
CTO Surgepays
[email protected]

[kaby76]

The javascript/javascript parser for the CSharp target works. But, all that is given is the grammar (JavaScriptLexer.g4, JavaScriptParser.g4) and some support code for the parser (JavaScriptLexerBase.cs, JavaScriptParserBase.cs). A driver is required. And, the grammar has to be processed by the Antlr tool to generate JavaScriptParser. There is a lexer grammar, and the tool must process that as well to generate the JavaScriptLexer class, which is used by the parser.

You can write the driver code yourself, but I find that laborious. I recommend that you install my Trash toolkit, and generate a driver program. After working with that, you can fit the parser in where you need.

Requirements

• Git. https://git-scm.com/downloads
• Install dotnet 7.x. https://dotnet.microsoft.com/en-us/download
• Install Python3. https://www.python.org/downloads/
• Install pip. https://pip.pypa.io/en/stable/installation/
• Install antlr4-tools. https://github.com/antlr/antlr4-tools
• Install Trash. https://github.com/kaby76/Domemtech.Trash#install
• Do not have java.exe on your path, or if you do, it must be version 11 or better! The Antlr tool is a Java jar that requires at least version 11. Do not have JAVA_HOME environmental variable set. These tend to confuse things.

Test requirements

Make sure all is working. Check.

$ python3 --version
Python 3.10.4
07/15-04:16:03 ~/issues/g4-3612/javascript/javascript/Generated-CSharp
$ pip --version
pip 23.1.2 from C:\Users\Kenne\AppData\Local\Programs\Python\Python310\lib\site-packages\pip (python 3.10)
07/15-04:16:11 ~/issues/g4-3612/javascript/javascript/Generated-CSharp
$ dotnet --version
7.0.302
07/15-04:16:17 ~/issues/g4-3612/javascript/javascript/Generated-CSharp
$ java --version
openjdk 11.0.1 2018-10-16
OpenJDK Runtime Environment 18.9 (build 11.0.1+13)
OpenJDK 64-Bit Server VM 18.9 (build 11.0.1+13, mixed mode)
$ antlr4
ANTLR Parser Generator  Version 4.13.0
 -o ___              specify output directory where all output is generated
 -lib ___            specify location of grammars, tokens files
 -atn                generate rule augmented transition network diagrams
 -encoding ___       specify grammar file encoding; e.g., euc-jp
 -message-format ___ specify output style for messages in antlr, gnu, vs2005
 -long-messages      show exception details when available for errors and warnings
 -listener           generate parse tree listener (default)
 -no-listener        don't generate parse tree listener
 -visitor            generate parse tree visitor
 -no-visitor         don't generate parse tree visitor (default)
 -package ___        specify a package/namespace for the generated code
 -depend             generate file dependencies
 -D<option>=value    set/override a grammar-level option
 -Werror             treat warnings as errors
 -XdbgST             launch StringTemplate visualizer on generated code
 -XdbgSTWait         wait for STViz to close before continuing
 -Xforce-atn         use the ATN simulator for all predictions
 -Xlog               dump lots of logging info to antlr-timestamp.log
 -Xexact-output-dir  all output goes into -o dir regardless of paths/package
07/15-04:16:58 ~/issues/g4-3612/javascript/javascript/Generated-CSharp

Generate a driver

Then, in a command-line shell type the following commands. I generally use Msys (Cygwin) since cmd.exe is such a terrible shell. You can use pwsh.exe (Powershell) if you prefer.

git clone https://github.com/antlr/grammars-v4.git
cd grammars-v4/javascript/javascript
dotnet tool restore
dotnet trgen -- -t CSharp
cd Generated-CSharp
dotnet build

You can then open the .csproj in Visual Studio, then open Test.cs and read how it works.

I would recommend that you use an up-to-date version of Visual Studio. VS2019 is many years old. And, as far as I know, there is no extension for VS2019 or VS2022 that supports Antlr.

Run

./bin/Debug/net7.0/Test.exe input-file.js

Notes

Do not reference antlr4.runtime. That is OLD OLD OLD code. Remove that package reference. Read the .csproj file generated. It uses antlr4.runtime.standard, the current, official, supported Antlr4 code. For dotnet/msbuild support of the .g4's (ie, processing the .g4's by the tool to generate .cs recognizers), use Antlr4BuildTasks.

Attached is a zip file for the parser. Just type "dotnet build" to rebuild.

Generated-CSharp.zip