Feat/long-term schduler

__tests__/algorithm.test.ts

@@ -327,7 +327,7 @@ describe('FSRS apply_fuzz', () => {
 })
 
 describe('change Params', () => {
-  test('change FSRSParameters', () => {
+  test('change FSRSParameters[FSRS]', () => {
     const f = fsrs()
     // I(r,s),r=0.9 then I(r,s)=s
     expect(f.interval_modifier).toEqual(1)
@@ -366,6 +366,54 @@ describe('change Params', () => {
 
     f.parameters = {} // check default values
     expect(f.parameters).toEqual(generatorParameters())
+
+    f.parameters.enable_short_term = false
+    expect(f.parameters.enable_short_term).toEqual(false)
+  })
+
+  test('change FSRSParameters[FSRSAlgorithm]', () => {
+    const params = generatorParameters()
+    const f = new FSRSAlgorithm(params)
+    // I(r,s),r=0.9 then I(r,s)=s
+    expect(f.interval_modifier).toEqual(1)
+    expect(f.parameters).toEqual(generatorParameters())
+
+    const request_retention = 0.8
+    const update_w = [
+      1.14, 1.01, 5.44, 14.67, 5.3024, 1.5662, 1.2503, 0.0028, 1.5489, 0.1763,
+      0.9953, 2.7473, 0.0179, 0.3105, 0.3976, 0.0, 2.0902, 0.48, 0.64,
+    ]
+    f.parameters = generatorParameters({
+      request_retention: request_retention,
+      w: update_w,
+      enable_fuzz: true,
+    })
+    expect(f.parameters.request_retention).toEqual(request_retention)
+    expect(f.parameters.w).toEqual(update_w)
+    expect(f.parameters.enable_fuzz).toEqual(true)
+    expect(f.interval_modifier).toEqual(
+      f.calculate_interval_modifier(request_retention)
+    )
+
+    f.parameters.request_retention = default_request_retention
+    expect(f.interval_modifier).toEqual(
+      f.calculate_interval_modifier(default_request_retention)
+    )
+
+    f.parameters.w = default_w
+    expect(f.parameters.w).toEqual(default_w)
+
+    f.parameters.maximum_interval = 365
+    expect(f.parameters.maximum_interval).toEqual(365)
+
+    f.parameters.enable_fuzz = default_enable_fuzz
+    expect(f.parameters.enable_fuzz).toEqual(default_enable_fuzz)
+
+    f.parameters = {} // check default values
+    expect(f.parameters).toEqual(generatorParameters())
+
+    f.parameters.enable_short_term = false
+    expect(f.parameters.enable_short_term).toEqual(false)
   })
 
   test('calculate_interval_modifier', () => {

__tests__/impl/long-term_schduler.test.ts

@@ -0,0 +1,248 @@
+import {
+  createEmptyCard,
+  fsrs,
+  FSRSAlgorithm,
+  generatorParameters,
+  Grade,
+  Rating,
+  State,
+} from '../../src/fsrs'
+import LongTermScheduler from '../../src/fsrs/impl/long_term_schduler'
+
+describe('Long-term  schduler', () => {
+  const w = [
+    0.4197, 1.1869, 3.0412, 15.2441, 7.1434, 0.6477, 1.0007, 0.0674, 1.6597,
+    0.1712, 1.1178, 2.0225, 0.0904, 0.3025, 2.1214, 0.2498, 2.9466, 0.4891,
+    0.6468,
+  ]
+  const params = generatorParameters({ w, enable_short_term: false })
+  const f = fsrs(params)
+  // Grades => const grade: Grade[] = [Rating.Again, Rating.Hard, Rating.Good, Rating.Easy]
+
+  test('test1', () => {
+    let card = createEmptyCard()
+    let now = new Date(2022, 11, 29, 12, 30, 0, 0)
+    const ratings: Grade[] = [
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+      Rating.Again,
+      Rating.Again,
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+      Rating.Good,
+    ]
+    const ivl_history: number[] = []
+    const s_history: number[] = []
+    const d_history: number[] = []
+    for (const rating of ratings) {
+      const record = f.repeat(card, now)[rating]
+      card = record.card
+      ivl_history.push(card.scheduled_days)
+      s_history.push(card.stability)
+      d_history.push(card.difficulty)
+      now = card.due
+    }
+
+    expect(ivl_history).toEqual([3, 6, 17, 42, 95, 200, 8, 2, 3, 5, 8, 14, 23])
+    expect(s_history).toEqual([
+      0.57587467, 6.28341418, 16.83356103, 41.95128557, 95.07063986,
+      199.53765138, 8.31519008, 1.96276113, 3.06877302, 4.90880017, 8.15177579,
+      13.50873393, 22.92901865,
+    ])
+    expect(d_history).toEqual([
+      7.1434, 7.1434, 7.1434, 7.1434, 7.1434, 7.1434, 9.00990564, 10,
+      9.80746516, 9.62790717, 9.46045139, 9.30428213, 9.15863867,
+    ])
+  })
+
+  test('test2', () => {
+    let card = createEmptyCard()
+    let now = new Date(2022, 11, 29, 12, 30, 0, 0)
+    const ratings: Grade[] = [
+      Rating.Again,
+      Rating.Hard,
+      Rating.Good,
+      Rating.Easy,
+      Rating.Again,
+      Rating.Hard,
+      Rating.Good,
+      Rating.Easy,
+    ]
+    const ivl_history: number[] = []
+    const s_history: number[] = []
+    const d_history: number[] = []
+    for (const rating of ratings) {
+      const record = f.repeat(card, now)[rating]
+      card = record.card
+      ivl_history.push(card.scheduled_days)
+      s_history.push(card.stability)
+      d_history.push(card.difficulty)
+      now = card.due
+    }
+    expect(ivl_history).toEqual([1, 2, 3, 8, 2, 2, 4, 10])
+
+    expect(s_history).toEqual([
+      0.21652154, 0.51780862, 1.8183783, 8.18593986, 1.96087115, 2.23717242,
+      3.33185406, 10.31008873,
+    ])
+    expect(d_history).toEqual([
+      9.00990564, 9.81735598, 9.63713135, 8.53580104, 10, 10, 9.80746516,
+      8.69465435,
+    ])
+  })
+
+  test('test3', () => {
+    let card = createEmptyCard()
+    let now = new Date(2022, 11, 29, 12, 30, 0, 0)
+    const ratings: Grade[] = [
+      Rating.Hard,
+      Rating.Good,
+      Rating.Easy,
+      Rating.Again,
+      Rating.Hard,
+      Rating.Good,
+      Rating.Easy,
+      Rating.Again,
+    ]
+    const ivl_history: number[] = []
+    const s_history: number[] = []
+    const d_history: number[] = []
+    for (const rating of ratings) {
+      const record = f.repeat(card, now)[rating]
+      card = record.card
+      ivl_history.push(card.scheduled_days)
+      s_history.push(card.stability)
+      d_history.push(card.difficulty)
+      now = card.due
+    }
+    expect(ivl_history).toEqual([2, 3, 17, 3, 4, 6, 18, 3])
+
+    expect(s_history).toEqual([
+      0.35311368, 3.40179546, 16.86596974, 2.9223039, 3.73601023, 6.27595217,
+      18.057595, 2.96541083,
+    ])
+    expect(d_history).toEqual([
+      8.07665282, 8.01375158, 7.02183706, 8.89653604, 9.71162749, 9.53852896,
+      8.44384445, 10,
+    ])
+  })
+
+  test('test4', () => {
+    let card = createEmptyCard()
+    let now = new Date(2022, 11, 29, 12, 30, 0, 0)
+    const ratings: Grade[] = [
+      Rating.Good,
+      Rating.Easy,
+      Rating.Again,
+      Rating.Hard,
+      Rating.Good,
+      Rating.Easy,
+      Rating.Again,
+      Rating.Hard,
+    ]
+    const ivl_history: number[] = []
+    const s_history: number[] = []
+    const d_history: number[] = []
+    for (const rating of ratings) {
+      const record = f.repeat(card, now)[rating]
+      card = record.card
+      ivl_history.push(card.scheduled_days)
+      s_history.push(card.stability)
+      d_history.push(card.difficulty)
+      now = card.due
+    }
+
+    expect(ivl_history).toEqual([3, 17, 3, 4, 8, 30, 4, 4])
+
+    expect(s_history).toEqual([
+      0.57587467, 17.3937106, 2.98322161, 4.08808234, 7.99405969, 29.76078201,
+      3.78204811, 4.44627015,
+    ])
+    expect(d_history).toEqual([
+      7.1434, 6.21014718, 8.13955406, 9.0056661, 8.88014936, 7.82983963,
+      9.65007924, 10,
+    ])
+  })
+  test('test5', () => {
+    let card = createEmptyCard()
+    let now = new Date(2022, 11, 29, 12, 30, 0, 0)
+    const ratings: Grade[] = [
+      Rating.Easy,
+      Rating.Again,
+      Rating.Hard,
+      Rating.Good,
+      Rating.Easy,
+      Rating.Again,
+      Rating.Hard,
+      Rating.Good,
+    ]
+    const ivl_history: number[] = []
+    const s_history: number[] = []
+    const d_history: number[] = []
+    for (const rating of ratings) {
+      const record = f.repeat(card, now)[rating]
+      card = record.card
+      ivl_history.push(card.scheduled_days)
+      s_history.push(card.stability)
+      d_history.push(card.difficulty)
+      now = card.due
+    }
+
+    expect(ivl_history).toEqual([4, 1, 2, 3, 13, 3, 3, 5])
+
+    expect(s_history).toEqual([
+      0.93916394, 0.70772253, 1.16119435, 3.42301186, 12.97577367, 2.53486926,
+      3.06202367, 4.60523893,
+    ])
+    expect(d_history).toEqual([
+      6.21014718, 8.13955406, 9.0056661, 8.88014936, 7.82983963, 9.65007924, 10,
+      9.80746516,
+    ])
+  })
+
+  test('[State.(Re)Learning]switch long-term schduler', () => {
+    // Good(short)->Good(long)->Again(long)->Good(long)->Good(short)->Again(short)
+    const ivl_history: number[] = []
+    const s_history: number[] = []
+    const d_history: number[] = []
+    const state_history: string[] = []
+
+    const grades: Grade[] = [
+      Rating.Good,
+      Rating.Good,
+      Rating.Again,
+      Rating.Good,
+      Rating.Good,
+      Rating.Again,
+    ]
+    const short_term = [true, false, false, false, true, true]
+
+    let now = new Date(2022, 11, 29, 12, 30, 0, 0)
+    let card = createEmptyCard(now)
+    const f = fsrs({ w })
+    for (let i = 0; i < grades.length; i++) {
+      const grade = grades[i]
+      const enable = short_term[i]
+      f.parameters.enable_short_term = enable
+      const record = f.repeat(card, now)[grade]
+      card = record.card
+      now = card.due
+      ivl_history.push(card.scheduled_days)
+      s_history.push(card.stability)
+      d_history.push(card.difficulty)
+      state_history.push(State[card.state])
+    }
+    expect(ivl_history).toEqual([0, 4, 1, 4, 12, 0])
+    expect(s_history).toEqual([
+      3.0412, 3.0412, 1.20788692, 3.83856852, 12.23542321, 2.48288917,
+    ])
+    expect(d_history).toEqual([4.49094334, 4.66971892, 6.70295066, 6.73263695,6.76032238,8.65264745])
+    expect(state_history).toEqual(['Learning', 'Review', 'Review', 'Review','Review','Relearning'])
+  })
+})

src/fsrs/algorithm.ts

@@ -71,7 +71,7 @@ export class FSRSAlgorithm {
     this.update_parameters(params)
   }
 
-  private params_handler_proxy(): ProxyHandler<FSRSParameters> {
+  protected params_handler_proxy(): ProxyHandler<FSRSParameters> {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     const _this: FSRSAlgorithm = this
     return {

src/fsrs/default.ts

@@ -9,6 +9,7 @@ export const default_w = [
   0.6468,
 ]
 export const default_enable_fuzz = false
+export const defualt_enable_short_term = true
 
 export const FSRSVersion: string = 'v3.5.7 using FSRS V5.0'
 
@@ -28,8 +29,10 @@ export const generatorParameters = (
     request_retention: props?.request_retention || default_request_retention,
     maximum_interval: props?.maximum_interval || default_maximum_interval,
     w: w,
-    enable_fuzz: props?.enable_fuzz || default_enable_fuzz,
-  }
+    enable_fuzz: props?.enable_fuzz ?? default_enable_fuzz,
+    enable_short_term:
+      props?.enable_short_term ?? defualt_enable_short_term,
+  } satisfies FSRSParameters
 }
 
 /**

src/fsrs/fsrs.ts

@@ -16,12 +16,32 @@ import type { int } from './types'
 import { FSRSAlgorithm } from './algorithm'
 import { TypeConvert } from './convert'
 import BasicScheduler from './impl/basic_schduler'
+import LongTermScheduler from './impl/long_term_schduler'
 
 export class FSRS extends FSRSAlgorithm {
   private Schduler
   constructor(param: Partial<FSRSParameters>) {
     super(param)
-    this.Schduler = BasicScheduler
+    const { enable_short_term } = this.parameters
+    this.Schduler = enable_short_term ? BasicScheduler : LongTermScheduler
+  }
+
+  protected override params_handler_proxy(): ProxyHandler<FSRSParameters> {
+    const _this: FSRS = this satisfies FSRS
+    return {
+      set: function (target, prop, value) {
+        if (prop === 'request_retention' && Number.isFinite(value)) {
+          _this.intervalModifier = _this.calculate_interval_modifier(
+            Number(value)
+          )
+        } else if (prop === 'enable_short_term') {
+          _this.Schduler = value === true ? BasicScheduler : LongTermScheduler
+        }
+        // @ts-ignore
+        target[prop] = value
+        return true
+      },
+    }
   }
 
   /**