Published
Edited
Jan 16, 2021
Importers
selection
function map(any, fun) {
if (any instanceof Array)
return any.map(fun)
if (any instanceof Object) {
const result = {}
for (let key in any)
result[key] = fun(any[key])
return result;
}
return fun(any)
}
function push(buffer = [], items = [], limit = 1) {
buffer.push(...items)
while (buffer.length > limit)
buffer.shift()
return buffer;
}
function slide(buffer = [], limit = 1) {
return (...items) => push(buffer, items, limit)
}
async function* tail(agen, opts) {
let {
n,
i = 0,
k = 60,
buf = [],
cap = Infinity,
fun = async v => v
} = opts || {};
for await (let item of agen) {
if (buf.push(await fun(item)) >= cap)
buf = buf.slice(-cap)
if (i++ >= n && n != null)
break;
else if (i % k == 0)
yield buf;
}
yield buf;
}
async function* tails(agen, opts) {
let {
n,
i = 0,
k = 1,
bufs = {},
cap = Infinity,
fun = async v => v
} = opts || {};
for await (let obj of agen) {
for (let key in obj) {
let buf = bufs[key] || (bufs[key] = [])
if (buf.push(...await fun(obj[key])) >= cap)
buf = bufs[key] = buf.slice(-cap)
if (i++ >= n && n != null)
break;
else if (i % k == 0)
yield bufs;
}
}
yield bufs;
}
function* windows(array, T = 1, W = T) {
// every T, window of size W
for (let i = 0; i < array.length; i += T) {
yield array.slice(i, i + W)
}
}
Purpose-built for displays of data
Observable is your go-to platform for exploring data and creating expressive data visualizations. Use reactive JavaScript notebooks for prototyping and a collaborative canvas for visual data exploration and dashboard creation.
