Over 2 decades of experience on the Web…
buffer = {
try {
const stream = await data.file(label).stream();
const reader = stream.getReader();
let done, value;
while ((({ done, value } = await reader.read()), !done)) {
yield value;
}
} catch (error) {
return [];
}
}
async function* pipe(
container /* node */,
trickle /* iterable */,
{ amount = 1000, chunk = 5, start = -1 } = {}
) {
let i = start;
container.textContent = "";
for (const n of await trickle) {
container.textContent +=
i < 0
? n + (i === -1 ? ".\n" : "")
: (i && i % chunk === 0 ? " " : "") + n;
yield container.textContent.replace(/\s/g, "").split("");
if (++i === amount) break;
}
}
/*!
* GOTCHA: Avoid defining the spigot functions using shorthand syntax
*/
spigot = ({
/* {{{ Pi: */
pi: function* (n = NaN) {
for (
let p, q, k = 2n, a = 4n, b = 1n, a_ = 12n, b_ = 4n;
isNaN(+n) || n > -1;
k++
) {
[p, q] = [k * k, 2n * k + 1n];
[a, b, a_, b_] = [a_, b_, p * a + q * a_, p * b + q * b_];
for (let d; (d = a / b) === a_ / b_ && (isNaN(+n) || n > -1); n--) {
yield Number(d);
[a, a_] = [10n * (a % b), 10n * (a_ % b_)];
}
/* thank you, Matz! - mg */
}
},
pi_: function* (n = NaN) {
SWEEP: for (
let i = 2n, q = 1n, r = 180n, t = 60n, u, y;
isNaN(+n) || n > -1;
i++, n--
) {
y = (q * (27n * i - 12n) + 5n * r) / (5n * t);
u = 3n * (3n * i + 1n) * (3n * i + 2n);
r = 10n * u * (q * (5n * i - 2n) + r - y * t);
q = 10n * q * i * (2n * i - 1n);
t *= u;
yield Number(y);
}
},
/* }}} */
/* {{{ Napier's constant: */
e: function (digits = 1000) {
const e = [];
SWEEP: for (
let bump = 9,
A = Array.from(Array((digits += bump)), (_, i) =>
!i ? 0 : !(1 - i) ? 2 : 1
),
x = 0;
digits > bump;
) {
for (let n = digits--; --n; ) {
A[n] = x % n;
x = 10 * A[n - 1] + Math.trunc(x / n);
}
e.push(x);
/* thank you, Xavier Gourdon - mg */
}
return (e.shift() + "").split("").map(Number).concat(e);
},
e_: function (digits = 1000) {
const e = [2];
SWEEP: for (
let i = 0,
A = Array(digits + 3).fill(1),
B = Array.from(A, (_, i) => i + 2),
j,
q;
i < digits;
i++
) {
A = Array.from(A, (x) => x * 10);
for (j = A.length - 1; j > -1; --j > -1 && (A[j] += q)) {
q = Math.trunc(A[j] / B[j]);
A[j] = A[j] % B[j];
}
e.push(q);
}
return e;
}
/* }}} */
})
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.
