This repository contains a JavaScript compiler implemented using ANTLRv4 and Java. The compiler performs lexical analysis, parsing, semantic analysis, and generates both a parse tree and an abstract syntax tree (AST) for JavaScript code.

• ANTLR Grammar: Utilizes the hello.g4 file in the src directory to define the JavaScript grammar.
• ANTLR Recognizer Generation: Generates ANTLR recognizer classes using the ANTLR tool.
• Lexer and Parser: Utilizes ANTLR-generated lexer and parser for JavaScript grammar.
• Semantic Analysis: Performs semantic analysis to ensure correctness and coherence of the input code.
• Parse Tree and AST Generation: Generates a parse tree and an abstract syntax tree (AST) representing the structure of the JavaScript code.
• Error Handling: Implements robust error handling mechanisms to provide informative messages for syntax and semantic errors.
• Optimizations: (Optional) Includes any optimizations or enhancements applied to the generated AST or code.

• Java Development Kit (JDK): Download and install JDK
• ANTLRv4: Download and install ANTLR

1. Install ANTLR:

   # On Unix-based systems (Linux/Mac)
   cd /usr/local/lib
   sudo curl -O https://www.antlr.org/download/antlr-4.x-complete.jar
   export CLASSPATH=".:/usr/local/lib/antlr-4.x-complete.jar:$CLASSPATH"
   alias antlr4='java -jar /usr/local/lib/antlr-4.x-complete.jar'
   alias grun='java org.antlr.v4.gui.TestRig'

   # On Windows
   # Download the ANTLR JAR from https://www.antlr.org/download.html
   # Set up CLASSPATH and alias commands accordingly

2. Generate ANTLR Recognizer:

   antlr4 src/hello.g4

3. Compile the generated files:

   javac -cp .:antlr-4.x-complete.jar src/*.java

1. Run the compiler:

   # Replace 'YourMainClass' with the actual main class of your compiler
   java -cp .:antlr-4.x-complete.jar src/YourMainClass input.js

# Replace 'YourCompilerExecutable' with the actual name of your compiled executable
./YourCompilerExecutable input.js