@danielnarey/record

[Deprecated] A tiny functional data structure for static key-value stores

Deprecation Warning: This experimental library is no longer in active development and will not be updated in response to Node.js version releases or security vulnerabilities identified in the dependency tree.

Purpose

When you have key-value data that should only be set once in the context of an application, using a record gives you convenient accessors, while preventing you from accidentally modifying your application's source of truth.

A record is just a thin layer of abstraction over Object, which makes it trivial to serialize record data to JSON for storage and retrieval.

Examples

import record from '@danielnarey/record';
// OR: const record = require('@danielnarey/record');

// constructor
const rec = record.from({
  banana: '🍌',
  grapes: '🍇',
  cherries: '🍒',
  watermelon: '🍉',
});

typeof(rec); //--> 'function'

// accessors
record.get(rec, 'grapes');  //--> '🍇'
record.get(rec, 'pineapple'); //--> undefined

record.getAsPromise(rec, 'grapes').then(console.log); //--> '🍇'
record.getAsPromise(rec, 'pineapple').catch(() => console.log('🙈')); //--> '🙈'

record.getWithDefault(rec, 'grapes', '🙈'); //--> '🍇'
record.getWithDefault(rec, 'pineapple', '🙈'); //--> '🙈'

// conversion
record.toString(rec); //--> '{"banana":"🍌","grapes":"🍇","cherries":"🍒","watermelon":"🍉"}'

API

from(obj) => ({...})

Create an immutable record from a shallow clone of an object, returning a functional interface to the record (denoted as ({...})).

get(rec, k) => v|undefined

Returns the value associated with key k in record rec, or undefined if no such key exists.

getAsPromise(rec, k, [test, [err]]) => Promise<v|err>

If k exists in rec and passing its associated value v to test returns true, getAsPromise returns a promise resolving to v. If k does not exist or test returns false, getAsPromise returns a promise that rejects with err. If a test function is not supplied, the default test returns true for any value that is not undefined or null.

getWithDefault(rec, k, d, [test]) => v|d

If k exists in rec and passing its associated value v to test returns true, getWithDefault returns v. If k does not exist or test returns false, getWithDefault returns d. If a test function is not supplied, the default test returns true for any value that is not undefined or null.

keys(rec) => [...]

Returns an array containing all of the keys in rec.

toString(rec) => '{...}'

Returns the contents of rec as a JSON string.

Prior Art

• Racket/rebellion: records
• Elm: records