CostOf.Life


This is the CostOf.Life library and command line client.

For a more general description about the project check website: thecostof.life

Installation

install it with cargo install costoflife

Examples

To add a single transaction use the command costoflife add:

``
|> costoflife add Netflix 7.99€ 100320 1m12x .movies .covid
`

See it in action:

![asciicast](https://asciinema.org/a/382419)

Transactions

The library interpret transactions and calculate for each transaction its _per diem_ amount. For a longer explanation check the CostOf.life website.

A transaction as the properties:
- Name: a descriptive name
- Amount: the amount in monetary currency
- Lifetime: a duration that the transaction applies to
- Start date: the start date since when the lifetime should be computed
- Tags: for grouping transactions

As a simple interface the library interprets strings into transactions, the format of the string is shown in the examples and the details are listed below.


$3

The library tokenize the input string and looks for the patterns listed below. Anything that cannot be recognized as a pattern it will set as the title of the transaction. The title is required

#### Amount

The monetary value of the transaction, required:

`EBNF
Amount ::= Natural ( '.' Digit Digit? )? "€"

Natural ::= NaturalDigit Digit*
NaturalDigit ::= #'[1-9]'
Digit ::= "0" | NaturalDigit
`

Currently the only available currency is €

Examples:
- 10€
- 10000.99€


#### Lifetime

The duration of transaction, optional, defaults to 1d.

`EBNF
Lifetime ::= Duration Repeat?

Duration ::= Natural TimeUnit
Repeat ::= Natural "x"
TimeUnit ::= "d" | "w" | "m" | "y"
`

where the TimeUnit is:
- d days
- w weeks
- m months
- y years

Examples:
- 1m12x => one month for 12 times, for example for monthly expenses like monthly subscriptions (Netflix, etc)
- 12m => twelve months for 1 time, same as 1y
- 1w52x => one week 52 times, for example weekly groceries expenses for all the year

> 💡 the number of repeats they influence the total amount of the transaction: 10€ 1m12x will result of a transaction of total amount of 120€ while 12m1x will result in a single transaction of 10€ over 12 months


#### Start date

The transaction start date, optional, defaults to the current date, it uses the little endian format (day, month, year).

`EBNF
Date ::= Day Month Year

Month ::= "1" #'[0-2]' | "0" NaturalDigit
Day ::= '0' #'[1-9]' | #'[1-2]' Digit | '3' #'[0-1]'
Year ::= Digit Digit

Natural ::= NaturalDigit Digit*
NaturalDigit ::= #'[1-9]'
Digit ::= "0" | NaturalDigit
`

Examples:
- 030521 => March the 3rd, 2021
- 312122 => December the 31st, 2022

#### Tags

To label transactions, optional. For convenience it uses the hashtag format.

`EBNF
HashTag ::= ('#' | '.') Word

EOL ::= '\r'? '\n'
Word ::= AlphaNum+ [ (' ' | '\t')+ | EOL ]
AlphaNum ::= #'[A-Za-z0-9_-]'
`

Examples:
- #lifestile
- .whatever

Appendix

Here the full grammar

`EBNF

Tx ::= ( Amount | Lifetime | StartDate | HashTag ) ( SEP ( Amount | Lifetime | StartDate | HashTag ) )+ EOL

EOL ::= '\r'? '\n'
SEP ::= (' ' | '\t')+

Lifetime ::= Duration Repeat?

Duration ::= Natural TimeUnit
Repeat ::= Natural "x"
TimeUnit ::= "d" | "w" | "m" | "y"

StartDate ::= Day Month Year

Month ::= "1" #'[0-2]' | "0" NaturalDigit
Day ::= '0' #'[1-9]' | #'[1-2]' Digit | '3' #'[0-1]'
Year ::= Digit Digit

Amount ::= Natural ( '.' Digit Digit? )? "€"

Natural ::= NaturalDigit Digit*
NaturalDigit ::= #'[1-9]'
Digit ::= "0" | NaturalDigit
Int ::= "+" | "-" Digit+

HashTag ::= ('#' | '.') Word

Word ::= AlphaNum+
AlphaNum ::= #'[A-Za-z0-9_-]'
`

---
Made by adgb

Techincal Setup

1. Install rust
2. Install cargo-edit: cargo install cargo-edit. Cargo edit is used to manage dependencies.
3. Install cargo-bump: cargo install cargo-bump`. Cargo bump is used to bump release versions.