@pdfking/structs

Runtime

checks

ArrayQ

const ArrayQ = Array.isArray

Type guard function that checks if a value is an array. Returns true if the value is an array, false otherwise.

Parameters

arg The value to check

Returns True if the value is an array, false otherwise

Example

import { ArrayQ } from "@pdfking/structs"

ArrayQ([1, 2, 3]) // true
ArrayQ("hello") // false

// Use in conditional logic
const input: string | string[] = "hello"
ArrayQ(input) ? input : [input] // ["hello"]

BigintQ

const BigintQ = <T>(value: T): value is bigint & T

Type guard function that checks if a value is a bigint. Returns true if the value is a bigint, false otherwise.

Parameters

value The value to check

Returns True if the value is a bigint, false otherwise

Example

import { BigintQ } from "@pdfking/structs"

BigintQ(10n) // true
BigintQ(10) // false

BooleanQ

const BooleanQ = <T>(value: T): value is boolean & T

Type guard function that checks if a value is a boolean. Returns true if the value is a boolean, false otherwise.

Parameters

value The value to check

Returns True if the value is a boolean, false otherwise

Example

import { BooleanQ } from "@pdfking/structs"

BooleanQ(true) // true
BooleanQ(1) // false

BytesQ

const BytesQ = <T>(value: T): value is Uint8Array & T

Type guard function that checks if a value is a Uint8Array. Returns true if the value is a Uint8Array, false otherwise.

Parameters

value The value to check

Returns True if the value is a Uint8Array, false otherwise

Example

import { BytesQ } from "@pdfking/structs"

BytesQ(new Uint8Array([1, 2, 3])) // true
BytesQ([1, 2, 3]) // false

FunctionQ

const FunctionQ = <T extends (...args: any[]) => any>(value: unknown): value is T

Type guard function that checks if a value is a function. Returns true if the value is a function, false otherwise.

Parameters

value The value to check

Returns True if the value is a function, false otherwise

NullQ

const NullQ = (value: unknown): value is null | undefined

Type guard function that checks if a value is null or undefined. Returns true if the value is null or undefined, false otherwise.

Parameters

value The value to check

Returns True if the value is null or undefined, false otherwise

Example

import { NullQ } from "@pdfking/structs"

NullQ(null) // true
NullQ(undefined) // true
NullQ("hello") // false

// Use in conditional logic
const input: string | undefined = undefined
NullQ(input) ? "default" : input // "default"

NumberQ

const NumberQ = <T>(value: T): value is number & T

Type guard function that checks if a value is a number. Returns true if the value is a number, false otherwise.

Parameters

value The value to check

Returns True if the value is a number, false otherwise

Example

import { NumberQ } from "@pdfking/structs"

const num = 42;
const str = "42";

if (NumberQ(num)) {
  console.log(num.toFixed(2)); // "42.00" (type narrowed to number)
}

if (NumberQ(str)) {
  // This block won't execute
}

// Use in filtering
const mixed = [1, "two", 3, "four"];
const numbers = mixed.filter(NumberQ); // [1, 3]

RecordQ

const RecordQ = (value: unknown): value is Record<string, unknown>

StringQ

const StringQ = <T>(value: T): value is string & T

Type guard function that checks if a value is a string. Returns true if the value is a string, false otherwise.

Parameters

value The value to check

Returns True if the value is a string, false otherwise

Example

import { StringQ } from "@pdfking/structs"

const str = "hello";
const num = 42;

if (StringQ(str)) {
  console.log(str.toUpperCase()); // "HELLO" (type narrowed to string)
}

if (StringQ(num)) {
  // This block won't execute
}

// Use in filtering
const mixed = [1, "two", 3, "four"];
const strings = mixed.filter(StringQ); // ["two", "four"]

functions

Render

const Render = <N extends string, T = {}, R = string>(
  names: { [K in N]: (ctx: NoInfer<T>) => R },
  item: EnumType<N, T>
): R

types

ContentType

const enum ContentType {
  BYTES = "application/octet-stream",
  HTML = "text/html",
  JSON = "application/json",
  JPEG = "image/jpeg",
  PDF = "application/pdf",
  PNG = "image/png",
  TEXT = "text/plain",
  TIFF = "image/tiff",
  WASM = "application/wasm",
  WEBP = "image/webp",
  ZIP = "application/zip",
  IDML = "application/vnd.adobe.indesign-idml-package",
  XML = "text/xml",
}