calculatrs

A python-like calculator for simple math on the terminal. It only supports a handful of basic operators; if you need more, just use actual python. If you only need to do simple arithmetic, though, this should be fine.

Currently:

• All integers are 128-bit signed

• All floating-point values are 64-bit IEEE754.

• Integers are coerced to floats in mixed expressions.

• Values can be explicitly cast to a type: int(2.0) or float(2). For integers, this truncates the value.

• Integers support the following basic operations:

  • +, -, *, /: basic arithmetic. Note that we use integer division for integer-typed operands.
  • <<, >>: left and right shift
  • b ** e: b raised to the power e. If e is a float, b is cast to a float also. If e is an integer, e is cast to a 32-bit unsigned integer.

• Floats support the following basic operations:

  • +, -, *, /: basic arithmetic. Note that we use floating-point division for float-typed operands.
  • b ** e: b raised to the power e. e may be a float or an integer, but if it is an integer, it will be truncated to 32-bits.

• Precedence aims to be sane, though I haven't tested thoroughly:

  +, -	Lower Precedence
  All others	Higher Precence

• All operators are right-associative.

• Expressions can be grouped with ( <expr> ), as one would expect.

• The special _ value represents the previous (typed) result, which is stored in /tmp/calculatrs. It can be used any place a value is expected. If an error occurs, no change is made to the saved value.

• In order to make it easier to use directly in the terminal, the following alternate syntaxes exist:

  • * == x
  • ** == ^^

Building

You will need stable Rust.

cargo build

Installing

You can install from cargo:

cargo install calculatrs

The installed binary is called c.

Usage

Suppose you install the binary on your path

> c 10 / 5
2
> c '10 / 5'
2

Beware of your shell expanding * into "list all files".