Calculator is a simple and intuitive antlr4 calculator.

1. Install Java 1.6+ and ANTLR v4
2. Generate ANTLR files java org.antlr.v4.Tool Calc.g -visitor -o output
3. Copy Listener & Visitor implementations cp *.java output
4. Compile javac output/*.java

You can use Calculator in two ways: command mode and interactive mode.

This is probably the mode you'll want to use. To do this, just write a text file as the following:

193
a = 5
b = 6
a+b*2
(1+2)*3

then,

$ cd output && java Calc calc.txt

Instead of writing a lot of small text files, you can use interactive mode.

$ cd output && java Calc
193
a = 5
b = 6
a+b*2
(1+2)*3
EOF      # type ctrl-D on Unix or Ctrl+Z on Windows

Calculator support the basic arithmetic operators (+, -, *, /, %), unary operators (+, -), expressions, parenthesized expressions, user-defined functions, integer numbers, floating-point numbers, and variables.

1. Add support for exponentiation operator ^.