Calkt is a Kotlin library that supports parsing and calculating various expressions. Parser is written in a way to have an ability to be extended.

• Calkt
  • Example
  • Implementation
  • Modules
    • core
    • math
    • units
    • example

The result of running example/Main.kt:

Enter math expression to calculate: 2   2 * 2
Parsed as: 2 plus (2 times 2)
Result: 6

Enter an expression with units to calculate: (1km - 0.5mi)   2 yd to inches
Parsed as: (((1 Kilometers) minus (0.5 Miles)) plus (2 Yards)).convert(Inches)
Result: 7886.272 Inches

You can get latest version from Releases tab on GitHub.

dependencies {
  implementation("me.y9san9.calkt:units:$version")
}

The library consists of several different modules:

Module with all basic types for parsing and calculating. Here you can find ParseContext and CalculateContext as well as functions to launch parsers/calculators.

Module with implementation of basic math expressions that any calculator can calculate. This is where you can find logic to calculate numbers combined with basic supported operators ( , -, *, /). You can implement your own operator, like in this example (% operator).

Module with implementation of math expressions with units. It depends on math module heavily and does not do any calculations on its own. There is a logic to support calculation and conversions of units like 1 km 2, 1km to inches, etc.

Module with all the examples you need to know. If something is missing, PRs are welcome.