Calculator

A simple command line scientific calculator implemented in C. Utilises the shunting yard algorithm to process infix expressions.

Features:

• Generic stack implementation.
• Infix expression strings.
• Early evaluation.
• Precedence-aware calculation.
• Single-argument functions.
• Actually descriptive error messages.
• Mathematical constants and previous answer memory.

Functions:

• sqrt(...) square root.
• sin(...) sine.
• cos(...) cosine.
• tan(...) tangent.
• More soon.^TM

Constants:

• pi Pi.
• e Euler's number.
• ans Previous answer.