Daphne

Software in process of development. Don't have any high expectations.

Daphne is a simple math shell which allows perform basic calculations.

Quick Start

$ git clone https://github.com/Sylphri/daphne
$ cd daphne
$ cargo run

Shell Reference

Expressions

Expressions can consist of numbers, basic operations, sums, products and functions calls.

Numbers

You can use arbitrary real numbers. Dot . used as separator between integer and fractional parts.

-> 3.14

Leading or trailing zeros can be omitted.

-> .5 (same as 0.5)

Basic Operations

Operation	Description
`+`	Addition
`-`	Subtraction
`*`	Multiplication
`/`	Division
`^`	Exponentiation

-> 3.5 + 9^2
 = 84.5

Also you can rearrange priorities of operations with parenthesis.

-> (2 + 3) * 4
 = 20

Sums and Products

You can calculate sum or product of some sequence with sums and products.

Sum operation have next syntax:

(sum lower_bound upper_bound step with ident: expr)

Where lower_bound is inclusive, upper_bound is exclusive, ident is name of iterative variable which contains current value for each iteration and expr is expression which would evaluated on each iteration.

In this example we are summing up all natural numbers from 1 to 9.

-> (sum 1 10 1 with it: it)
 = 45

Product have the same syntax but with keword prod instead sum.

Function Calls

You can use builtin and user-defined functions in expressions.

Function calls have next syntax:

ident(param1, param2, param3, ...)

Where ident is a name of called function and each param is arbitrary expression.

-> sin(3.14)
 = 0.001592...

Function Definitions

To define a new function you need to use keyword def.

def ident(arg1, arg2, arg3, ...) = expr

Where ident is a function name, each arg is a name of argument and expr is a function body.

-> def vec2_len(a, b) = sqrt(a*a + b*b)
  Successfully defined
-> vec2_len(3, 4)
 = 5

Builtin Functions and Std module

There are some functions out of the box, some of them are builtin and some are in std module.

You can get list of builtin functions by entering command builtin.

-> builtin
  abs(x)    - Computes the absolute value of x.
  sin(x)    - Computes the sine of x (in radians).
  ...

And to get functions from std module you can use command load.

-> load std
  Successfully loaded 19 functions

Be careful, command load accepts file path as a parameter, so example above may not work if you in a wrong folder.

Commands

Command	Description
help	Prints help message
builtin	Prints list of builtin functions
exit	Exits the program
save path	Saves all defined functions into provided file
load path	Loads functions from provided file
list [flags]	Prints list of defined functions
remove [flags] [ident] ...	Removes provided functions
plot ident	Plots given function

Yes, you can do plots with this tool.

Sylphri / daphne