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:

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.

Parsing rules

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:

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.

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).

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.

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

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

Examples:

• #lifestile
• .whatever

Appendix

Here the full grammar

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.