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lookup()

lookup<A, B>(obj, def?): <C>(prop) => A[C]

Takes an object and an optional fallback function and returns a function that takes a string and returns the lookup value or the result default fallback.

Type Parameters​

• A extends Record<string | number | symbol, unknown>

• B extends (...args) => any

Parameters​

obj​

A

The table lookup object.

def?​

B

The function used to handle the default value if the lookup returns undefined.

Returns​

Function

Type Parameters​

• C extends string | number | symbol

Parameters​

prop​

string | number | symbol

Returns​

A[C]

Remark​

pure function

Example​

const colorTable = {
 FOO: [0, 0, 255, 155],
 BAR: [255, 0, 255, 155],
 FIZZ: [230, 0, 0, 155],
 BUZZ: [0, 128, 0, 155],
};

const colorLookup = tableLookup(colorTable, x => x ?? [128, 128, 128, 155]);
colorLookup(data.value);