fp-ts-std/dist/esm/IO.js

The missing pseudo-standard library for fp-ts.

import * as IO from "fp-ts/IO";
import { constVoid, flow } from "fp-ts/function";
import { pass as _pass, unless as _unless, when as _when } from "./Applicative";
import { until as _until } from "./Monad";
export const once = (f) => {
    const uncalled = Symbol();
    let val = uncalled;
    return x => {
        if (val === uncalled)
            val = f(x);
        return IO.of(val);
    };
};
export const whenInvocationCount = (p) => f => {
    let n = 0;
    return () => {
        n++;
        if (p(n))
            f();
    };
};
export const execute = (x) => x();
export const when = _when(IO.Applicative);
export const unless = _unless(IO.Applicative);
export const memoize = (f) => {
    const empty = Symbol();
    let res = empty;
    return () => (res === empty ? (res = f()) : res);
};
export const sequenceArray_ = flow(IO.sequenceArray, IO.map(constVoid));
export const traverseArray_ = f => flow(IO.traverseArray(f), IO.map(constVoid));
export const pass = _pass(IO.Applicative);
export const until = _until(IO.Monad);