eva

simple calculator REPL, similar to bc(1), with syntax highlighting and persistent history

installation

• Homebrew

$ brew install eva

• crates.io

$ cargo install eva

• manual

$ git clone https://github.com/nerdypepper/eva
$ cd eva
$ cargo run

usage

eva 0.3.1
NerdyPepper <akshayoppiliappan@gmail.com>
Calculator REPL similar to bc(1)
USAGE:     eva [OPTIONS] [INPUT]
ARGS:     <INPUT>    Optional expression string to run eva in command mode
OPTIONS:     -b, --base <RADIX>    Radix of calculation output (1 - 36) [default: 10]     -f, --fix <FIX>       Number of decimal places in output (1 - 64) [default: 10]     -h, --help            Print help information     -r, --radian          Use radian mode     -V, --version         Print version information

type out an expression and hit enter, repeat.

> 1 + sin(30)
1.5
> floor(sqrt(3^2 + 5^2))
5
> 5sin(45) + cos(0)
4.53553

updating

- crates.io

$ cargo install eva --force

- manual

$ cargo install --force --path /path/to/eva

operators

- binary operators: + - / ^ * - unary operators: + -

constants

some constants available in rust standard library.

e      pi

examples:

pi * 5^2  # πr²

functions

all trigonometric functions expect input in degrees.

1 argument:
sin    cos     tan    csc    sec    cot    sinh   cosh   tanh
asin   acos    atan   acsc   asec   acot   ln     log2   log10
sqrt   ceil    floor  abs
2 arguments: log    nroot
deg(x) - convert x to degrees rad(x) - convert x to radians

examples:

sqrt(sin(30)) # parentheses are mandatory for functions

log10100      # no log10(100)    # yes
log(1, 10)    # function with two arguments

quality of life features

- auto insertion of * operator

>12sin(45(2))             # 12  sin(45  (2)) 12

- auto balancing of parentheses

>ceil(sqrt(3^2 + 5^2      # ceil(sqrt(3^2 + 5^2)) 6

- use previous answer with _

> sin(pi) 0.0548036650 > _^2 0.0030034417 >

• super neat error handling

> 1 + ln(-1)
Domain Error: Out of bounds!

- syntax highlighting

todo

- add support for variables (pi, e, _ (previous answer)) - syntax highlighting - multiple arg functions - screenshots - create logo - unary operators (minus, plus) - add detailed error handler - add unit tests - lineditor with syntax highlighting - add more functions

contributors

the rust community has helped eva come a long way, but these devs deserve a special mention for their contributions:

Ivan Tham Milan Marković asapokl