mathparser

A simple math expression parser and evaluator written in c++ that showcase an implementation of various design patterns.

Build and Run

To build and run the mathparser executable, use the following commands:

./scripts/build.sh mathparser_exe
./install/bin/mathparser_exe

Design patterns

This project intentionally uses several well-known design patterns to make the parser modular and easy to extend:

• Composite — IExpression and FunctionExpression form a composite structure so expressions can contain nested sub-expressions (children are stored in FunctionExpression::arg_).
• Strategy — The BaseFunction class defines an interface for a function's evaluation; concrete functions (AddFunction, MultFunction, SinFunction, etc.) implement evaluateImpl, letting behavior vary independently of the expression tree.
• State — The parser uses ParserState and concrete states (InitState, FuncState, CoefState, TransState) to manage parsing behavior depending on the current context.
• Interpreter — Parser and FunctionExpression::Evaluate() implement an interpreter-like pattern to evaluate parsed expressions.
• Registry / Factory — FunctionMap registers function implementations and provides lookup by name or operator; this central registry simplifies function creation and lookup.

UML diagram

The class diagram is available in docs/uml/mathparser_core.puml (PlantUML). You can render it locally (requires PlantUML and Graphviz):

# SVG
plantuml -tsvg docs/uml/mathparser_core.puml
# PNG
plantuml -tpng docs/uml/mathparser_core.puml

Source: docs/uml/mathparser_core.puml. A PNG version is also available at docs/uml/mathparser_core.png.