NMCalc v0.4

NMCalc is primarily a desktop calculator application. It is very young project, but already has useful functions.

Download

Download JAR or source of the lates release here.

Compilation

This is a Maven project. To build it, run mvn package in the root directory of the project (contains pom.xml). If everything goes well, this will create directory target and a jar file inside it. The jar file is executable and can be run directly.

Usage

The application window is divided into three parts (from top to bottom): history window, input window and result window. Enter an expression into the input window (the middle one), the result is shown as you type in the result window (the bottom one). To commit the expression into the history window, press Ctrl + Enter.

Features

Variables

The variable assignment syntax is simply:

x = <expression>

Variables are remembered between different expression evaluations, can hold value of any type (real, list, boolean, function, etc.).

Built-in Functions

The built-in mathematical functions include:

• trigonometric functions (sin, asin, cos, acos, tan, atan),
• natural logarithm function (ln),
• least common multiplier function (lcm),
• power and square root function (pow and sqrt respectively),
• absolute value, ceiling and floor functions (abs, ceil and floor respectively).

User-defined Functions

There are some builtin functions, such as sin(<real>), apply(<value>, <arguments>) or eval(<expression>). Apart from those, users can define custom functions using the syntax:

def myFunction(<arguments>) <expression>

For example, factorial would be defined as:

def factorial(x) if x > 1 then x * factorial(x - 1) else 1

Function calls use a C-like syntax, for example: factorial(5). Note - function definitions are themselfs expressions, which evaluate to the function itself (functions are first-class objects and as such can be assigned to variables, passed to function arguments or returned by a function).

Pattern matching

The pattern matching syntax is:

match <expression> {
  case <pattern 1> -> <expression>
  case <pattern 2> -> <expression>
  ...
}

Example:

def append(lst, value) match lst {
  case first :: rest -> first :: append(lst, value)
  case [] -> [value]
}

append([1, 2, 3], 4) => [1, 2, 3, 4]