PostJava: Basic PostScript Interpreter

This is a console application written in the Java programming language, implementing a PostScript interpreter with its most common and basic operations, categorized as:

• Stack
• Arithmetic
• Dictionary
• String
• Boolean
• Flow Control
• Input/Output

Instructions for Program Set-Up and Execution

1. Install the Java Runtime Environment
   • Since this program is entirely written in Java, you'll need to have a version of JRE downloaded and installed to your machine if you don't already. You can find the necessary JRE at this link.
2. Configure the Local Bash/Batch Files for Program Execution (optional)
   • There are four different scripts at the root of the project directory, the configuration of these scripts provides the best user experience for this interpreter, but is not necessary.
   • Files ending in .bat are for users of the Windows operating system, while files ending in .sh are for users of Unix-like operating systems, such as Linux distributions or Macintosh.
   • Windows Configuration Guide:
     1. Via Windows File Explorer, navigate to the location in which you've chosen to store the project folder.
     2. Once there, you should see a file named install_pj.bat, right-click this file and then click 'Run as Administrator'. If you have a terminal window currently open, you will be prompted to restart it after this step.
     3. Now open the Windows Search Bar, search for your favorite command-line interface (Powershell, Git Bash, CMD, etc.), and type and enter pj to invoke the interpreter. NOTE: I did not officially test this batch script, as I am running this program via Linux, I apologize for my laziness. Should it not work, Jump over to the traditional method.
   • Unix/Linux Configuration Guide:
     1. Via your system terminal, navigate to the project's root directory via cd path/to/project.
     2. Type and enter the following to ensure the bash scripts are executable: chmod +x ps install_pj.sh
     3. Then, to configure the installation script, type and enter sudo ./install_pj.sh, and enter your password when prompted.
     4. You can now enter pj from any directory in your terminal to invoke the interpretor.
3. If You Prefer the Traditional Method of Compiling and Running
   • Windows:
     1. Compile: javac -cp "/lib/*" test/*.java src/*.java main/*.java
     2. RunL java -cp "lib/*;main;src;test" Main
   • Unix/Linux:
     1. Compile: javac -cp "lib/*" test/*.java src/*.java main/*.java
     2. Run: java -cp "lib/*:main:src:test" Main

Lexical & Dynamic Scoping

By default the interpreter uses dynamic scoping, and you as the user are made aware of what scope the interpreter is using via the prompt [PJ:D > 0], where the character 'D' designates the interpreter is using dynamic scoping. By entering the command lex, the interpreter will switch over to lexical scope, and to switch back, simply enter the command dyn.