Returns the index of the first instance; when called a second time, returns the index of the second instance; and so on. Works with arrays and strings. Packaged as a Node.js module.
npm install sequential-indexof --saveconst sequentialIndexOf = require('sequential-indexof')
const array = ['a', 'b', 'a']
const indexOf = sequentialIndexOf(array) // returns a function
indexOf('a') // returns 0, the first index of 'a'
indexOf('a') // returns 2, the second index of 'a'
indexOf('a') // returns -1, since there are no more instances of 'a'
indexOf('b') // returns 1, the first index of 'b'
indexOf('b') // returns -1, since there are no more instances of 'b'
indexOf('c') // returns -1, since there are no instances of 'c'