About The Project

rb-fsrs is a Ruby Gem implements Free Spaced Repetition Scheduler algorithm. It helps developers apply FSRS in their flashcard apps.

Getting Started

gem install fsrs

or

bundle add fsrs

Usage

Create a card and review it at a given time:

require 'fsrs'

scheduler = Fsrs::Scheduler.new
card = Fsrs::Card.new
now = DateTime.now.utc
scheduling_cards = scheduler.repeat(card, now)

There are four ratings:

Rating::AGAIN # forget; incorrect response
Rating::HARD # recall; correct response recalled with serious difficulty
Rating::GOOD # recall; correct response after a hesitation
Rating::EASY # recall; perfect response

Get the new state of card for each rating:

scheduling_cards[Rating::AGAIN].card
scheduling_cards[Rating::HARD].card
scheduling_cards[Rating::GOOD].card
scheduling_cards[Rating::EASY].card

Get the scheduled days for each rating:

card_again.scheduled_days
card_hard.scheduled_days
card_good.scheduled_days
card_easy.scheduled_days

Update the card after rating GOOD:

card = scheduling_cards[Rating::GOOD].card

Get the review log after rating GOOD:

review_log = scheduling_cards[Rating::GOOD].review_log

Get the due date for card:

due = card.due

There are four states:

State::NEW # Never been studied
State::LEARNING # Been studied for the first time recently
State::REVIEW # Graduate from learning state
State::RELEARNING # Forgotten in review state

Acknowledgements

• Open Spaced Repetition
• py-fsrs

This library was ported from py-fsrs to Ruby. Much refactoring to be done, but the core logic is the same.

License

Distributed under the MIT License. See LICENSE for more information.