calculator

>> (10) - 2 + 4;
[0] 4
>> 2 * 0x03
[1] 6
>> $ ^ $$
[2] 1296
>> $2 % 5
[3] 1

Installation

$ cargo install --locked --git https://github.com/Techno-coder/calculator

Execution

$ calculator

Basic mode does not update on each key press and may work better for less advanced terminals.

$ calculator -b/--basic

Evaluation mode reads from the standard input pipe and outputs results directly.

$ echo expression | calculator -e/--evaluation

Arithmetic Operators

In order of precedence:

• + - Add
• - - Minus
• * - Multiply
• / - Divide
• % - Modulo
• ^ - Power

Numerical Formats

• 0x000a - Hexadecimal
• 0b1010 - Binary
• 0o0012 - Octal
• 1.0 - Floating
• 1e1 - Scientific

Variables

• $ - Last evaluation result
• $$ - Second last evaluation result
• $$...$ - Arbitrary position evaluation result
• $0 - Variable with identifier 0
• $aa - Variable with identifier aa

Functions

>> function argument

Functions take the term immediately to the right. Whitespace is required after the function name.

• abs - Absolute value
• sqrt - Square root
• cbrt - Cube root
• ln - Natural logarithm
• log2 - Binary logarithm
• log10 - Decimal logarithm

Trigonometry

• sin - Sine
• cos - Cosine
• tan - Tangent
• asin - Inverse sine
• acos - Inverse cosine
• atan - Inverse tangent

The trigonometric functions can take and return degrees by appending ':

>> asin' 1
[0] 90

Constants

• e - Euler number
• pi - Pi (3.14)

Coalescence

• ; - Coalesce operator

The coalesce operator combines the previous two terms into a single node. This eliminates the need for parentheses.

>> 10 - 2 + 4;

is equivalent to:

>> 10 - (2 + 4)

Repetitions of the coalesce operator will combine more than two terms:

>> 1 / 1 + 2 + 3;;

is equivalent to:

>> 1 / (1 + 2 + 3)

Sometimes a combined term is nested inside another:

>> 1 / (2 - (3 + 4))

This can be achieved by leaving whitespace after the first coalescence:

>> 1 / 2 - 3 + 4; ;