TO RUN
-Clone this repository
-Open with Visual Studio
-Build and run the project with a single argument that points to a .java file
e.g.: C:/path/to/file.java
-The program will print the structure of the source code contained in the .java file
TO CREATE AN IMPLEMENTATION FOR A LANGUAGE
-Install the Antlr4 plugin https://www.antlr.org/tools.html
-Generate a Lexer and a Parser from a Grammar file (.g4)
- Right click a _Lexer.g4 file and go to Tools > Configure ANTLR...
- Set the language for the source files that will be generated (in this case "CSharp" - not the language that is actually getting parsed)
- Right click the _Lexer.g4 again and run Tools > Generate ANTLR Recognizer
- Repeat for a _Parser.g4
-Manually fix the generated files if necessary
- Include a BaseParser.cs file from https://github.com/antlr/grammars-v4 if required. It will be found in a "CSharp" folder inside of the desired language folder.
- Replace token names in the generated Lexer file with their numeric equivalents (e.g. LPAREN with 73 - found in the .tokens file) if necessary.
- Certain function names like "Lt" might use a different runtime version name "LT"
- The Parser constructor may have too many arguments outside of the InputStream parameter - remove them.
- The _input ITokenStream may be protected. The InputStream parameter from the constructor can be saved locally.
-Create Listeners for each type of node in the language's abstract syntax tree
- The visitor classes instantiate a Lexer and a Parser to parse a string of code
- An example is provided in Java
REFERENCE
-https://tomassetti.me/antlr-mega-tutorial
-https://github.com/antlr/antlr4
-https://www.antlr.org/tools.html