About Calculate

Calculate is a Mac OS X widget for evaluating math expressions. It uses JavaScript with some modifications (like ^ for pow and ! for factorial). Users can define their own variables and functions. Variables and functions are persistently stored.

Visit the Calculate home page

How it works

Calculate has a custom ANTLR grammar similar to JavaScript, but with the following changes:

• ^ and ** are power operators.
• >< is the xor operator.
• ! is factorial.
• Binary literals: 0b101010.
• Octal literals: 0o52.
• Numbers with leading zeros are treated as decimal literals.

After parsing the input to a grammar tree, ECMAScript3ExtEmitter.js converts the tree to standard JavaScript source code, and Calc.js executes it using eval().