19 lines
580 B
TypeScript
19 lines
580 B
TypeScript
/**
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* Make a map and return a function for checking if a key
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* is in that map.
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* IMPORTANT: all calls of this function must be prefixed with
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* \/\*#\_\_PURE\_\_\*\/
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* So that rollup can tree-shake them if necessary.
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*/
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export function makeMap(
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str: string,
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expectsLowerCase?: boolean
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): (key: string) => boolean {
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const map: Record<string, boolean> = Object.create(null)
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const list: Array<string> = str.split(',')
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for (let i = 0; i < list.length; i++) {
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map[list[i]] = true
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}
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return expectsLowerCase ? val => !!map[val.toLowerCase()] : val => !!map[val]
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}
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