odiff.js
function arrayToMap(array) {
    var result = {}
    array.forEach(function(v) {
        result[v] = true
    })
    return result
}
function arrayToMap(array) {
    var result = {}
    array.forEach(function(v) {
        result[v] = true
    })
    return result
}
function arrayToMap ( array ) { var result = { } array . forEach ( function ( v ) { result [ v ] = true } ) return result }
turns an array of values into a an object where those values are all keys that point to 'true'
turns an array of values into a an object where those values are all keys that point to true