# @yobuligo/core.typescript > Core TypeScript Latest version **1.0.12** (published 2023-06-11) · ISC license · 0 weekly downloads ## Install ```sh npm install @yobuligo/core.typescript pnpm add @yobuligo/core.typescript yarn add @yobuligo/core.typescript bun add @yobuligo/core.typescript ``` ## Health **Score 25/100 (F)** — status: abandoned. Positive: has types; no vulnerabilities; high quality score. Warnings: low downloads; no esm support. Negative: abandoned; low maintenance score. ## Facts | | | |---|---| | Version | 1.0.12 | | Published | 2023-06-11 | | First published | 2023-02-17 | | Weekly downloads | 0 | | License | ISC | | TypeScript types | bundled | | Module format | CommonJS | | Dependencies | 0 | | Unpacked size | 56.2 KB | | Known vulnerabilities | 0 | | Install scripts | no | | GitHub stars | 0 | | Author | Yobuligo | | Maintainers | yobuligo | ## Links - npm: https://www.npmjs.com/package/@yobuligo/core.typescript - Repository: https://github.com/Yobuligo/core.typescript - Homepage: https://github.com/Yobuligo/core.typescript#readme - Issues: https://github.com/Yobuligo/core.typescript/issues - npm.io page: https://npm.io/package/@yobuligo/core.typescript ## Recent versions - 1.0.12 (latest) — 2023-06-11 - 1.0.11 — 2023-03-02 - 1.0.10 — 2023-03-02 - 1.0.9 — 2023-02-21 - 1.0.8 — 2023-02-21 - 1.0.7 — 2023-02-18 - 1.0.6 — 2023-02-18 - 1.0.5 — 2023-02-18 - 1.0.4 — 2023-02-18 - 1.0.3 — 2023-02-17 - 1.0.2 — 2023-02-17 - 1.0.1 — 2023-02-17 - 1.0.0 — 2023-02-17 ## README # core.typescript An API that extends TypeScript by simplified core functions and exceptions for standardizing. ## Installation Install the library via: ``` npm install --save @yobuligo/core.typescript ``` ## Functions The library provides the following functions. ### checkNotNull Checks and returns the provided parameter _value_ and expects it to be not null and to be not undefined. If the _value_ is null or undefined an _IllegalStateException_ is thrown. To provide an alternative text to the exception, parameter _message_ can be passed in. ``` function checkNotNull(value?: T, message: string = "Parameter 'value' must be not null and not undefined"): T ``` ### Enum Provides access to reflection functions for enums. The following example shows how to 1. get the keys of an Enum 2. get the values of an Enum 3. getting the first value for comparison reasons ``` enum Gender { MALE = "male", FEMALE = "female", } const keys = Enum.keys(Gender); // result: MALE, FEMALE const values = Enum.values(Gender); // result: male, female if (Enum.first(Gender) === Gender.MALE) { // returns true console.log("First entry is MALE"); } ``` ### error Throws an error and returns never. With parameter _message_ a text can be passed in. The function is useful to connect throwing an exception with the nullish coalescing operator, as _throw new_ cannot be used with ??. ``` function error(message?: string): never // example: const value = getValue() ?? error("Message"); ``` Throws an error and returns never. With parameter _error_ an alternative exception type can be passed in. The function is useful to connect throwing an exception with the nullish coalescing operator, as _throw new_ cannot be used with ??. ``` export function error(error: Error): never; // example: const value = getValue() ?? error(new IllegalStateException()); ``` ### ifNotNull Calls the function _block_ if the given _value_ is not null and not undefined. The function _block_ may return a value or undefined. ``` function ifNotNull(value: T, block: (value: NonNullable) => R | undefined): R | undefined ``` ### ifNull Calls the function _block_ if the given _value_ is null or undefined. The function _block_ may return a value or undefined. ``` function ifNull(value: T, block: () => R | undefined): R | undefined ``` ### lazy Provides an instance of type _ILazy_, to lazy load a value of type _T_, which is useful especially for loading, memory or CPU intensive values, only on demand. The value is provided via function _initializer_. ``` function lazy(initializer: () => T): ILazy ``` ### measureTimeMillis Executes the function _block_ and returns the measured execution time in millis. ``` function measureTimeMillis(block: () => void): number ``` ### newLine Creates a new line at the console. ``` function newLine(): void ``` ### objectPool Provides an instance of an object pool _IObjectPool_ for objects of type _T_. It keeps objects which are expensive to create in memory to be reused. The parameter _capacity_ defines the maximum number of instances which are created via function _creator_. ``` function objectPool(capacity: number, creator: (index: number) => T): IObjectPool ``` The following example shows how to 1. initialize an object pool for a demo database connection 2. acquire two database connections 3. release the first database connection to be reused ``` class DBConnectionDemo {} const dbConnectionPool = objectPool(3, () => { return new DBConnectionDemo(); }); const first = dbConnectionPool.acquire(); const second = dbConnectionPool.acquire(); // ... dbConnectionPool.release(first); ``` ### println Prints the given _data_ at the console. ``` function println(...data: any[]): void ``` ### pair Creates and returns an instance of _Pair_, which keeps the two readonly values _first_ and _second_. ``` function pair(first: A, second: B): Pair ``` ### repeat Repeats the execution of function _block_ for the given number _times_. For each call of function _block_ the current index is passed into. ``` function repeat(times: number, block: (index: number) => void): void ``` ### repeatDownTo Repeats the execution of function _block_ from number _from_ down to number _to_. For each call of function _block_ the current index is passed into. If _from_ is smaller than _to_ an _IllegalArgumentException_ is thrown. ``` function repeatDownTo(from: number, to: number, block: (index: number) => void): void ``` ### repeatUpTo Repeats the execution of function _block_ from number _from_ up to number _to_. For each call of function _block_ the current index is passed into. If _from_ is greater than _to_ an _IllegalArgumentException_ is thrown. ``` function repeatUpTo(from: number, to: number, block: (index: number) => void): void ``` ### TODO Throws an _NotImplementedException_. With parameter _message_ a text can be passed in. ``` function TODO(message: string = "Not implemented exception"): never ``` ### triple Creates and returns an instance of _Triple_, which keeps the three readonly values _first_, _second_ and _third_. ``` function triple(first: A, second: B, third: C): Triple ``` ## Exceptions The library provides the following exceptions. ### ClassCastException An exception that occurs in case of an invalid class type cast. ``` throw new ClassCastException(); ``` ### IllegalArgumentException An exception that occurs when an argument was provided, which is out of bounce. E.g. if a value -1 is passed into a function, which only excepts value greater 0. ``` throw new IllegalArgumentException(); ``` ### IllegalStateException An exception that occurs when a state is or becomes inconsistent. E.g. if a value must not be undefined but undefined is set as value. ``` throw new IllegalStateException(); ``` ### InvalidOperationException An exception that occurs when a method is invalid for the current object state. E.g. Fetching an object from an object pool whose capacity is already exhausted. ``` throw new InvalidOperationException(); ``` ### NoSuchElementException An exception that occurs when an expected result is not available. E.g. if a search for a specific value ends without result. ``` throw new NoSuchElementException(); ``` ### NotImplementedException An exception that occurs when the implementation of a routine was not yet completed. ``` throw new NotImplementedException(); ``` ### NotSupportedException An exception that occurs when a state is currently not valid. E.g. if a switch-case statement is called for a value that is currently not handled. ``` throw new NotSupportedException(); ``` ### NullPointerException An exception that occurs when a value is null or undefined, which was expected to be not null or undefined. ``` throw new NullPointerException(); ``` --- _Source: https://npm.io/package/@yobuligo/core.typescript · Machine-readable twin of the npm.io package page. Health data is recomputed on every publish._