68 lines
2.1 KiB
TypeScript
68 lines
2.1 KiB
TypeScript
/**
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* Handle values based on a field.
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*
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* @template {InvalidHandler} [Invalid=InvalidHandler]
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* @template {UnknownHandler} [Unknown=UnknownHandler]
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* @template {Record<string, Handler>} [Handlers=Record<string, Handler>]
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* @param {string} key
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* Field to switch on.
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* @param {Options<Invalid, Unknown, Handlers>} [options]
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* Configuration (required).
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* @returns {{unknown: Unknown, invalid: Invalid, handlers: Handlers, (...parameters: Parameters<Handlers[keyof Handlers]>): ReturnType<Handlers[keyof Handlers]>, (...parameters: Parameters<Unknown>): ReturnType<Unknown>}}
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*/
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export function zwitch<
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Invalid extends InvalidHandler = InvalidHandler,
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Unknown extends UnknownHandler = UnknownHandler,
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Handlers extends Record<string, Handler> = Record<string, Handler>
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>(
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key: string,
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options?: Options<Invalid, Unknown, Handlers> | undefined
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): {
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(...parameters: Parameters<Handlers[keyof Handlers]>): ReturnType<
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Handlers[keyof Handlers]
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>
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(...parameters: Parameters<Unknown>): ReturnType<Unknown>
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unknown: Unknown
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invalid: Invalid
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handlers: Handlers
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}
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/**
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* Handle a value, with a certain ID field set to a certain value.
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* The ID field is passed to `zwitch`, and it’s value is this function’s
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* place on the `handlers` record.
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*/
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export type Handler = (...parameters: any[]) => any
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/**
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* Handle values that do have a certain ID field, but it’s set to a value
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* that is not listed in the `handlers` record.
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*/
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export type UnknownHandler = (value: unknown, ...rest: any[]) => any
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/**
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* Handle values that do not have a certain ID field.
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*/
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export type InvalidHandler = (
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value: unknown,
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...rest: any[]
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) => void | null | undefined | never
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/**
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* Configuration (required).
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*/
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export type Options<
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Invalid extends InvalidHandler = InvalidHandler,
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Unknown extends UnknownHandler = UnknownHandler,
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Handlers extends Record<string, Handler> = Record<string, Handler>
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> = {
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/**
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* Handler to use for invalid values.
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*/
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invalid?: Invalid | undefined
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/**
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* Handler to use for unknown values.
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*/
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unknown?: Unknown | undefined
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/**
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* Handlers to use.
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*/
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handlers?: Handlers | undefined
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}
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