import { dropWhile } from "https://deno.land/x/aitertools@0.3.1/drop.ts";
Drops elements from the beginning of an async iterable as long as a specified condition is met, and yields the remaining elements.
import { dropWhile } from "./drop.ts";
async function* gen() { yield "foo"; yield "bar"; yield "baz"; yield "qux" }
const iterable = dropWhile(gen(), v => v !== "baz");
for await (const value of iterable) {
console.log(value);
}
The above example will print the following 2 lines:
baz
qux
An async predicate
function also works. The following example will print
the same 2 lines as the previous example:
import { dropWhile } from "./drop.ts";
async function* gen() { yield "foo"; yield "bar"; yield "baz"; yield "qux" }
const iterable = dropWhile(gen(), v => Promise.resolve(v !== "baz"));
for await (const value of iterable) {
console.log(value);
}
A predicate
function can take an index as well as the value.
import { dropWhile } from "./drop.ts";
async function* gen() { yield "foo"; yield "bar"; yield "baz"; yield "qux" }
const iterable = dropWhile(gen(), (_, i) => i % 2 === 0);
for await (const value of iterable) {
console.log(value);
}
The above example will print the following 3 lines:
bar
baz
qux
Parameters
predicate: (value: T, index: number) => (boolean | Promise<boolean>)
A predicate function to test each source element for a condition; the second parameter of the function represents the index of the source element. It can be either a synchronous or an asynchronous function.