Merge pull request #17 from satotake/add-features

Add features

Author: satotake

README.md

@@ -75,6 +75,49 @@ n.toNumerals()
   NumeralZero { raw: 123456789, unit: 0 } 
 ]
 ```
+
+#### Numerals.round 
+- round: : (base: JpNumeralUnit) => Numerals
+
+```ts
+import {numerals} from 'jp-numerals';
+const n = numerals(12_3456_7890)
+
+n.round(JpNumeralUnit.億).toString()
+// => returns
+'12億'
+
+```
+
+#### Signed methods
+
+- sign: () => Sign
+- toSignedNumerals: () => [Sign, Numeral[]]
+- toSignedTuples: () => [Sign, [number, string][]]
+- toSignedNumeralObjs: () => [Sign, NumeralObj[]]
+- toSignedString: () => string
+
+```ts
+import {numerals} from 'jp-numerals';
+const n = numerals(-123456789)
+
+n.sign()
+// => returns -1
+
+n.toSignedString()
+// => returns '-1億2345万6789'
+
+n.toSignedNumeralObjs()
+// => returns
+[
+  -1,
+  [
+    { unit: 2, character: '億', rank: 2, digits: 1 },
+    { unit: 1, character: '万', rank: 1, digits: 2345 },
+    { unit: 0, character: '', rank: 0, digits: 6789 } 
+  ]
+]
+```
 ---
 
 This library is based on [typescript-library-starter](https://github.com/alexjoverm/typescript-library-starter/)

__tests__/jp-numerals.ts

@@ -86,26 +86,74 @@ describe('jpNumerals', () => {
 
     expect(n.toString()).toEqual('12億3456万7890')
     expect(n.toNumber()).toEqual(1234567890)
+
+    const n2 = numerals(1_0000_0000)
+    expect(n2.toString()).toEqual('1億')
   })
 
   it('can handle float', () => {
     const n = numerals(12_3456_7890.123)
     expect(n.toTuples()).toEqual([[12, '億'], [3456, '万'], [7890.123, '']])
   })
 
-  it('throw error if number is negative', () => {
-    expect(() => numerals(-12_3456_7890.123)).toThrow()
+  it('can handle negative integer', () => {
+    const n = numerals(-12_3456_789_0)
+    const p = numerals(+12_3456_789_0)
+
+    expect(n.sign()).toEqual(-1)
+
+    expect(n.toAbsNumber()).toEqual(12_3456_789_0)
+    expect(n.toNumber()).toEqual(-12_3456_789_0)
+    expect(n.toSignedString()).toEqual('-12億3456万7890')
+    expect(p.toSignedString()).toEqual('12億3456万7890')
+    expect(n.toSignedTuples()).toEqual([-1, [[12, '億'], [3456, '万'], [7890, '']]])
+    expect(n.toSignedNumerals()).toEqual([-1, [
+      new Numeral(JpNumeralUnit.億, 12_3456_7890),
+      new Numeral(JpNumeralUnit.万, 12_3456_7890),
+      new Numeral(JpNumeralUnit.零, 12_3456_7890)
+    ]])
+    expect(n.toSignedNumeralObjs()).toEqual([-1, [
+      {
+        unit: JpNumeralUnit.億,
+        character: '億',
+        rank: 2,
+        digits: 12
+      },
+      {
+        unit: JpNumeralUnit.万,
+        character: '万',
+        rank: 1,
+        digits: 3456
+      },
+      {
+        unit: JpNumeralUnit.零,
+        character: '',
+        rank: 0,
+        digits: 7890
+      }
+    ]])
   })
 
   it('can use base as option', () => {
-    const n_base = numerals(12_3456, JpNumeralUnit.万)
+    const nBase = numerals(12_3456, JpNumeralUnit.万)
     const n = numerals(12_3456_0000)
 
-    expect(n_base.toTuples()).toEqual(n.toTuples())
-    expect(n_base.toNumerals()).toEqual(n.toNumerals())
-    expect(n_base.toNumeralObjs()).toEqual(n.toNumeralObjs())
+    expect(nBase.toTuples()).toEqual(n.toTuples())
+    expect(nBase.toNumerals()).toEqual(n.toNumerals())
+    expect(nBase.toNumeralObjs()).toEqual(n.toNumeralObjs())
+
+    expect(nBase.toString()).toEqual(n.toString())
+    expect(nBase.toNumber()).toEqual(1234560000)
+  })
+
+  it('can round number with specified unit', () => {
+    const positive = numerals(12_3456_7890)
+    const negative = numerals(-9999_9999_9999)
+
+    expect(positive.round(JpNumeralUnit.万).toString()).toEqual('12億3457万')
+    expect(positive.round(JpNumeralUnit.億).toString()).toEqual('12億')
 
-    expect(n_base.toString()).toEqual(n.toString())
-    expect(n_base.toNumber()).toEqual(1234560000)
+    expect(negative.round(JpNumeralUnit.万).toSignedString()).toEqual('-1兆')
+    expect(negative.round(JpNumeralUnit.億).toSignedString()).toEqual('-1兆')
   })
 })

src/jp-numerals.ts

@@ -1,7 +1,9 @@
-import { JpNumeralUnit, NumeralObj, Numerals } from './type'
-export { JpNumeralUnit, NumeralObj, Numerals }
+import { JpNumeralUnit, NumeralObj, Numerals, Sign } from './type'
+export { JpNumeralUnit, NumeralObj, Numerals, Sign }
 
+const EPSILON = 1e-10
 const log10 = (v: number) => Math.log(v) / Math.log(10)
+// for IE
 
 export class Numeral {
   raw: number
@@ -32,7 +34,7 @@ export class Numeral {
     return [digits, character]
   }
   toString(): string {
-    return `${this.digits}${this.character}`
+    return this.digits === 0 ? '' : `${this.digits}${this.character}`
   }
   toNumeralObj(): NumeralObj {
     const { unit, character, rank, digits } = this
@@ -59,28 +61,33 @@ export class NumeralZero extends Numeral {
 }
 
 export const numerals = (n: number, base: JpNumeralUnit = JpNumeralUnit.零): Numerals => {
-  // TODO(handle negative)
-  if (n < 0) {
-    throw Error('number must be string')
-  }
-
-  const raw = Math.abs(n) * Math.pow(10, base * 4)
+  const sign = n < 0 ? -1 : 1
+  const abs = Math.abs(n) * Math.pow(10, base * 4)
   // in myriads
 
-  const unitLen = Object.keys(JpNumeralUnit).length / 2
-  const numberLen = Math.ceil(log10(raw) / 4)
+  const unitLen = Object.keys(JpNumeralUnit).length / 2 // maximum unit
+  const numberLen = Math.ceil(log10(abs) / 4 + EPSILON)
   const len = Math.min(unitLen, numberLen)
-  const numerals = new Array(len)
+  const nums = new Array(len)
     .fill(NaN)
-    .map((_, i) => (i === 0 ? new NumeralZero(i, raw) : new Numeral(i, raw)))
+    .map((_, i) => (i === 0 ? new NumeralZero(i, abs) : new Numeral(i, abs)))
     .reverse()
 
   return {
-    toNumerals: () => numerals,
-    toTuples: () => numerals.map(numeral => numeral.toTuple()),
-    toNumeralObjs: () => numerals.map(numeral => numeral.toNumeralObj()),
-    toString: () => numerals.reduce((s, numeral) => `${s}${numeral}`, ''),
-    toNumber: () => raw
+    toNumerals: () => nums,
+    toTuples: () => nums.map(numeral => numeral.toTuple()),
+    toNumeralObjs: () => nums.map(numeral => numeral.toNumeralObj()),
+    toString: () => nums.reduce((s, numeral) => `${s}${numeral}`, ''),
+    toAbsNumber: () => abs,
+
+    sign: () => sign,
+    toSignedNumerals: () => [sign, nums],
+    toSignedTuples: () => [sign, nums.map(numeral => numeral.toTuple())],
+    toSignedNumeralObjs: () => [sign, nums.map(numeral => numeral.toNumeralObj())],
+    toSignedString: () => nums.reduce((s, numeral) => `${s}${numeral}`, sign === -1 ? '-' : ''),
+    toNumber: () => sign * abs,
+
+    round: (base: JpNumeralUnit) => numerals(sign * Math.round(abs / Math.pow(10, base * 4)), base)
   }
 }
 

src/type.ts

@@ -34,5 +34,16 @@ export interface Numerals {
   toTuples: () => [number, string][]
   toNumeralObjs: () => NumeralObj[]
   toString: () => string
+  toAbsNumber: () => number
+
+  sign: () => Sign
+  toSignedNumerals: () => [Sign, Numeral[]]
+  toSignedTuples: () => [Sign, [number, string][]]
+  toSignedNumeralObjs: () => [Sign, NumeralObj[]]
+  toSignedString: () => string
   toNumber: () => number
+
+  round: (base: JpNumeralUnit) => Numerals
 }
+
+export type Sign = -1 | 1