Not So Simple Java Calculator

Forked from mikailsheikh/cogitolearning-examples

This project is example calculator implementation with:

Lexer - to split string expression into tokens
Parser - to build AST from tokens sequence
Abstract Syntax Tree - to represent string expression as tree
Reverse Polish Notation - to calculate expression value

Design patterns

Iterator
Visitor
Composite
Singleton
Records in Java 16
Sealed Classes in Java 17
Pattern Matching in Java 17 (preview)
Guarded Pattern in Java 17 (preview)

Change added

Maven
JUnit5
Lombok
Decouple AST from calculation algorithm
Reverse Polish Notation as calculation algorithm
Fix code check style with Sonar, CodeMR, CheckStyle-IDEA and FindBugs-IDEA
Migration to Java 8
Migrate to Java 17