/eva

a calculator REPL, similar to bc(1)

Primary LanguageRustMIT LicenseMIT

heroimg.png

eva

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

eva.png

installation

  • crates.io
$ cargo install eva
  • manual
$ git clone https://github.com/nerdypepper/eva.git
$ cargo run

usage

eva 0.2.4
NerdyPepper <akshayoppiliappan@gmail.com>
Calculator REPL similar to bc(1)

USAGE:
    eva [FLAGS] [OPTIONS] [INPUT]

FLAGS:
    -h, --help       Prints help information
    -r, --radian     set eva to radian mode
    -V, --version    Prints version information

OPTIONS:
    -b, --base <RADIX>    set the radix of calculation output (2, 8, 10, 16 etc.)
    -f, --fix <FIX>       set number of decimal places in the output

ARGS:
    <INPUT>    optional expression string to run eva in command mode

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: + -

functions

all trignometric functions expect input in degrees.

sin    cos     tan    csc    sec    cot    sinh   cosh   tanh
asin   acos    atan   acsc   asec   acot   ln     log    sqrt
ceil   floor   abs

deg(x) - convert x to degrees
rad(x) - convert x to radians

examples:

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

log100        # no
log(100)      # yes

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
  • super neat error handling
> 1 + ln(-1)
Domain Error: Out of bounds!
  • syntax highlighting

todo

  • add support for variables (ans, pi, e)
  • 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