README.md

Calculator application

How to use

Run htncalc.exe and input expressions for calculation. For exit input "q" or "quit" command.

Supported features

• Integer and decimal positive numbers
• Arithmetic operations +, -, *, /
• Brackets
• abs() function

How it works

1. ExpressionParser performs lexical analysis of an input string expression.
2. PermutationsBuilder builds a terms tree considering sub-expressions priority with different "permutations services" which implements ITermPermuter interface. The order is important:
   1. BracketTermPermuter - distinguishes brackets
   2. FunctionTermPermuter - works with functions like abs(...)
   3. MulDivTermPermuter - for multiplication and division operations
   4. AddSubTermPermuter - for addition and subtraction operations
3. ExpressionTreeBuilder builds an expression tree, consists of IExpressionNode elements which can calculate their own value.