Safe Haskell	Safe-Inferred
Language	Haskell2010

FSRS.Types

Contents

Ratings
Memory state
Type synonyms

Description

The vocabulary shared by the whole package: the four grades a reviewer can give a card, and the two-variable memory state FSRS tracks for it.

Synopsis

data Rating
- = Again
- | Hard
- | Good
- | Easy
allRatings :: [Rating]
ratingToInt :: Rating -> Int
ratingFromInt :: Int -> Maybe Rating
data MemoryState = MemoryState {
- memoryStability :: !Stability
- memoryDifficulty :: !Difficulty
}
type Stability = Double
type Difficulty = Double
type Retrievability = Double
type Days = Double

Ratings

data Rating Source #

How well the card was recalled. The Enum instance counts from 0; the FSRS papers and reference implementations number the ratings from 1, which is what ratingToInt gives you.

Constructors

Again
Hard
Good
Easy

Instances

Instances details

Bounded Rating Source #
Instance details Defined in FSRS.Types Methods minBound :: Rating # maxBound :: Rating #
Enum Rating Source #
Instance details Defined in FSRS.Types Methods succ :: Rating -> Rating # pred :: Rating -> Rating # toEnum :: Int -> Rating # fromEnum :: Rating -> Int # enumFrom :: Rating -> [Rating] # enumFromThen :: Rating -> Rating -> [Rating] # enumFromTo :: Rating -> Rating -> [Rating] # enumFromThenTo :: Rating -> Rating -> Rating -> [Rating] #
Read Rating Source #
Instance details Defined in FSRS.Types Methods readsPrec :: Int -> ReadS Rating # readList :: ReadS [Rating] # readPrec :: ReadPrec Rating # readListPrec :: ReadPrec [Rating] #
Show Rating Source #
Instance details Defined in FSRS.Types Methods showsPrec :: Int -> Rating -> ShowS # show :: Rating -> String # showList :: [Rating] -> ShowS #
Eq Rating Source #
Instance details Defined in FSRS.Types Methods (==) :: Rating -> Rating -> Bool # (/=) :: Rating -> Rating -> Bool #
Ord Rating Source #
Instance details Defined in FSRS.Types Methods compare :: Rating -> Rating -> Ordering # (<) :: Rating -> Rating -> Bool # (<=) :: Rating -> Rating -> Bool # (>) :: Rating -> Rating -> Bool # (>=) :: Rating -> Rating -> Bool # max :: Rating -> Rating -> Rating # min :: Rating -> Rating -> Rating #

allRatings :: [Rating] Source #

Every rating, from Again to Easy.

ratingToInt :: Rating -> Int Source #

The rating as FSRS numbers it: 1 for Again through 4 for Easy.

ratingFromInt :: Int -> Maybe Rating Source #

Inverse of ratingToInt. Nothing outside 1..4.

Memory state

data MemoryState Source #

Everything FSRS remembers about a card.

Constructors

MemoryState
Fields memoryStability :: !Stability memoryDifficulty :: !Difficulty

Instances

Instances details

Read MemoryState Source #
Instance details Defined in FSRS.Types Methods readsPrec :: Int -> ReadS MemoryState # readList :: ReadS [MemoryState] # readPrec :: ReadPrec MemoryState # readListPrec :: ReadPrec [MemoryState] #
Show MemoryState Source #
Instance details Defined in FSRS.Types Methods showsPrec :: Int -> MemoryState -> ShowS # show :: MemoryState -> String # showList :: [MemoryState] -> ShowS #
Eq MemoryState Source #
Instance details Defined in FSRS.Types Methods (==) :: MemoryState -> MemoryState -> Bool # (/=) :: MemoryState -> MemoryState -> Bool #
Ord MemoryState Source #
Instance details Defined in FSRS.Types Methods compare :: MemoryState -> MemoryState -> Ordering # (<) :: MemoryState -> MemoryState -> Bool # (<=) :: MemoryState -> MemoryState -> Bool # (>) :: MemoryState -> MemoryState -> Bool # (>=) :: MemoryState -> MemoryState -> Bool # max :: MemoryState -> MemoryState -> MemoryState # min :: MemoryState -> MemoryState -> MemoryState #

Type synonyms

type Stability = Double Source #

Memory half-life in days: the larger it is, the slower the card is forgotten. In FSRS-7 stability is a genuine continuous quantity — sub-day values are meaningful and are what the model uses for same-day reviews.

type Difficulty = Double Source #

How hard the card is for this reviewer, on a [1, 10] scale.

type Retrievability = Double Source #

Probability of recall, in (0, 1].

type Days = Double Source #

A duration in days. Fractional values are meaningful throughout FSRS-7: ten minutes is 10 / 1440.