slice() function can get array as input

Author: Smoren

README.md

@@ -55,6 +55,7 @@ const originalView = view(originalArray);
 originalView.subview(mask([true, false, true, false, true])).toArray(); // [1, 3, 5]
 originalView.subview(select([1, 2, 4])).toArray(); // [2, 3, 5]
 originalView.subview(slice('::-1')).toArray(); // [5, 4, 3, 2, 1]
+originalView.subview(slice([,,-1])).toArray(); // [5, 4, 3, 2, 1]
 
 originalView.subview(mask([true, false, true, false, true])).apply((x: number) => x * 10);
 originalArray; // [10, 2, 30, 4, 50]

src/functions.ts

@@ -33,7 +33,7 @@ export function view<T>(source: Array<T> | ArrayViewInterface<T>, readonly?: boo
  *
  * This function allows you to create a selector for defining a subset of elements based on a slice range.
  *
- * @param {string | Slice} slice - The slice string or Slice object to create the selector from.
+ * @param {string | Array<number | undefined> | Slice} slice - The slice string or Slice object to create the selector from.
  *
  * @returns {SliceSelector} The created SliceSelector instance.
  *
@@ -52,7 +52,7 @@ export function view<T>(source: Array<T> | ArrayViewInterface<T>, readonly?: boo
  * const slicedArray = view.loc[sliceSelector.toString()];
  * console.log(slicedArray);
  * // [2, 3, 4] */
-export function slice(slice: string | Slice): SliceSelector {
+export function slice(slice: string | Array<number | undefined> | Slice): SliceSelector {
   return new SliceSelector(Slice.toSlice(slice));
 }
 

src/structs.ts

@@ -21,19 +21,23 @@ export class Slice {
   /**
    * Converts a slice string or Slice object into a Slice instance.
    *
-   * @param {string | Slice} s - The slice string or Slice object to convert.
+   * @param {string | Array<number | undefined> | Slice} s - The slice string/array or Slice object to convert.
    * @returns {Slice} The converted Slice instance.
    */
-  public static toSlice(s: string | Slice): Slice {
+  public static toSlice(s: string | Array<number | undefined> | Slice): Slice {
     if (s instanceof Slice) {
       return s;
     }
 
+    if (Array.isArray(s) && this.isSliceArray(s)) {
+      return new Slice(...(s as Array<number | undefined>));
+    }
+
     if (!this.isSliceString(s)) {
       throw new ValueError(`Invalid slice: "${String(s)}".`);
     }
 
-    const slice = this.parseSliceString(s);
+    const slice = this.parseSliceString(s as string);
 
     return new Slice(...slice);
   }
@@ -71,7 +75,32 @@ export class Slice {
 
     const slice = this.parseSliceString(s);
 
-    return !(slice.length < 1 || slice.length > 3);
+    return slice.length >= 1 && slice.length <= 3;
+  }
+
+  /**
+   * Checks if the provided value is a valid slice array.
+   *
+   * @param {unknown} s - The value to check.
+   *
+   * @returns {boolean} True if the value is a valid slice array, false otherwise.
+   */
+  public static isSliceArray(s: unknown): boolean {
+    if (!Array.isArray(s)) {
+      return false;
+    }
+
+    if(!(s.length >= 0 && s.length <= 3)) {
+      return false;
+    }
+
+    for (const item of s) {
+      if (item !== undefined && !Number.isInteger(item)) {
+        return false;
+      }
+    }
+
+    return true;
   }
 
   /**

tests/examples/examples.test.ts

@@ -29,6 +29,7 @@ it("Subview example", () => {
   expect(originalView.subview(mask([true, false, true, false, true])).toArray()).toEqual([1, 3, 5]);
   expect(originalView.subview(select([1, 2, 4])).toArray()).toEqual([2, 3, 5]);
   expect(originalView.subview(slice('::-1')).toArray()).toEqual([5, 4, 3, 2, 1]);
+  expect(originalView.subview(slice([,,-1])).toArray()).toEqual([5, 4, 3, 2, 1]);
 
   originalView.subview(mask([true, false, true, false, true])).apply((x: number) => x * 10);
   expect(originalArray).toEqual([10, 2, 30, 4, 50]);

tests/structs/slice.test.ts

@@ -226,3 +226,67 @@ function dataProviderForNormalize(): Array<unknown> {
     [':3:-1', 10, '9:3:-1', [9, 8, 7, 6, 5, 4]],
   ];
 }
+
+describe.each([
+  ...dataProviderForIsSliceArrayTrue(),
+] as Array<[Array<number>]>)(
+  "Is Slice Array",
+  (input: Array<number>) => {
+    it("", () => {
+      expect(Slice.isSliceArray(input)).toBeTruthy();
+    });
+  },
+);
+
+function dataProviderForIsSliceArrayTrue(): Array<unknown> {
+  return [
+    [[]],
+    [[,]],
+    [[,,]],
+    [[0]],
+    [[0,]],
+    [[0,,]],
+    [[1,,]],
+    [[1,0,]],
+    [[1,1,]],
+    [[-1,1,]],
+    [[1,,1]],
+    [[1,,2]],
+    [[,,1]],
+    [[,,-1]],
+    [[1,10,-1]],
+  ];
+}
+
+describe.each([
+  ...dataProviderForIsSliceArrayFalse(),
+] as Array<[Array<number>]>)(
+  "Is Slice Array",
+  (input: Array<number>) => {
+    it("", () => {
+      expect(Slice.isSliceArray(input)).toBeFalsy();
+    });
+  },
+);
+
+function dataProviderForIsSliceArrayFalse(): Array<unknown> {
+  return [
+    [['']],
+    [['a']],
+    [[0, 1, 'a']],
+    [[0, 1, 2, 3]],
+    [[1.1, 1, 2]],
+    [[1, 1, 2.2]],
+    [null],
+    [0],
+    [1],
+    [0.0],
+    [1.0],
+    [true],
+    [false],
+    [{}],
+    [{a: 1}],
+    [[{}]],
+    [[{a: 1}]],
+  ];
+}

tests/views/slice-view.test.ts

@@ -3,7 +3,7 @@ import {
   dataProviderForSliceOutOfBoundsPythonAutoGenerated,
   // @ts-ignore
 } from "../fixtures/python-slices";
-import { view } from "../../src";
+import { slice, view } from "../../src";
 
 describe.each([
   ...dataProviderForSliceSubviewRead(),
@@ -76,6 +76,40 @@ describe.each([
   },
 );
 
+
+describe.each([
+  ...dataProviderForSliceSubviewRead(),
+  ...dataProviderForSliceArraySubviewRead(),
+] as Array<[Array<number>, string | Array<number | undefined>, Array<number>]>)(
+  "Array View Slice Array Subview Loc Read Test",
+  (
+    source: Array<number>,
+    config: string | Array<number | undefined>,
+    expected: Array<number>,
+  ) => {
+    it("", () => {
+      // Given
+      const v = view(source);
+      const slicedArray = v.subview(slice(config)).loc[':'];
+
+      expect(slicedArray).toEqual(expected);
+      expect(slicedArray.length).toEqual(expected.length);
+
+      for (let i = 0; i < slicedArray.length; i++) {
+        expect(slicedArray[i]).toBe(expected[i]);
+      }
+
+      for (let i = 0; i < v.length; i++) {
+        expect(v.loc[i]).toBe(source[i]);
+      }
+
+      // And then
+      expect(v.toArray()).toEqual(source);
+      expect(slicedArray).toEqual(expected);
+    });
+  },
+);
+
 function dataProviderForSliceSubviewRead(): Array<unknown> {
   return [
     [[1, 2, 3, 4, 5, 6, 7, 8, 9], '1:6', [2, 3, 4, 5, 6]],
@@ -129,6 +163,17 @@ function dataProviderForSliceSubviewRead(): Array<unknown> {
   ];
 }
 
+function dataProviderForSliceArraySubviewRead(): Array<unknown> {
+  return [
+    [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1,6], [2, 3, 4, 5, 6]],
+    [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1,6,1], [2, 3, 4, 5, 6]],
+    [[1, 2, 3, 4, 5, 6, 7, 8, 9], [1,6,2], [2, 4, 6]],
+    [[1, 2, 3, 4, 5, 6, 7, 8, 9], [2,8], [3, 4, 5, 6, 7, 8]],
+    [[1, 2, 3, 4, 5, 6, 7, 8, 9], [2,8,1], [3, 4, 5, 6, 7, 8]],
+    [[1, 2, 3, 4, 5, 6, 7, 8, 9], [2,8,2], [3, 5, 7]],
+  ];
+}
+
 describe.each([
   ...dataProviderForSliceSubviewWrite(),
 ] as Array<[Array<number>, string, Array<number>, Array<number>]>)(
@@ -153,6 +198,31 @@ describe.each([
   },
 );
 
+describe.each([
+  ...dataProviderForSliceSubviewWrite(),
+  ...dataProviderForSliceArraySubviewWrite(),
+] as Array<[Array<number>, string | Array<number | undefined>, Array<number>, Array<number>]>)(
+  "Array View Slice Subview Loc Write Test",
+  (
+    source: Array<number>,
+    config: string | Array<number | undefined>,
+    toWrite: Array<number>,
+    expected: Array<number>,
+  ) => {
+    it("", () => {
+      // Given
+      const v = view(source);
+
+      // When
+      v.subview(slice(config)).loc[':'] = toWrite;
+
+      // And then
+      expect(v.toArray()).toEqual(expected);
+      expect(source).toEqual(expected);
+    });
+  },
+);
+
 function dataProviderForSliceSubviewWrite(): Array<unknown> {
   return [
     [[], ':', [], []],
@@ -173,3 +243,25 @@ function dataProviderForSliceSubviewWrite(): Array<unknown> {
     [[1, 2, 3, 4, 5, 6, 7, 8], '1:-1:2', [77, 88, 99], [1, 77, 3, 88, 5, 99, 7, 8]],
   ];
 }
+
+function dataProviderForSliceArraySubviewWrite(): Array<unknown> {
+  return [
+    [[], [], [], []],
+    [[], [,], [], []],
+    [[1], [,], [11], [11]],
+    [[1, 2, 3], [,], [2, 4, 6], [2, 4, 6]],
+    [[1, 2, 3], [0,], [2, 4, 6], [2, 4, 6]],
+    [[1, 2, 3], [0,3], [2, 4, 6], [2, 4, 6]],
+    [[1, 2, 3], [0,3], [2, 4, 6], [2, 4, 6]],
+    [[1, 2, 3], [1,], [22, 33], [1, 22, 33]],
+    [[1, 2, 3], [,2], [11, 22], [11, 22, 3]],
+    [[1, 2, 3], [,-1], [11, 22], [11, 22, 3]],
+    [[1, 2, 3, 4, 5, 6], [,,2], [77, 88, 99], [77, 2, 88, 4, 99, 6]],
+    [[1, 2, 3, 4, 5, 6], [,,-2], [77, 88, 99], [1, 99, 3, 88, 5, 77]],
+    [[1, 2, 3, 4, 5, 6], [1,,2], [77, 88, 99], [1, 77, 3, 88, 5, 99]],
+    [[1, 2, 3, 4, 5, 6], [-2,,-2], [77, 88, 99], [99, 2, 88, 4, 77, 6]],
+    [[1, 2, 3, 4, 5, 6, 7, 8], [,-2,2], [77, 88, 99], [77, 2, 88, 4, 99, 6, 7, 8]],
+    [[1, 2, 3, 4, 5, 6, 7, 8], [,6,2], [77, 88, 99], [77, 2, 88, 4, 99, 6, 7, 8]],
+    [[1, 2, 3, 4, 5, 6, 7, 8], [1,-1,2], [77, 88, 99], [1, 77, 3, 88, 5, 99, 7, 8]],
+  ];
+}