memoLastCall

Creates a memoized version of a function that caches only its most recent call

Usage

Creates a memoized version of a function that caches only its most recent call.

When the function is called with the same arguments as the previous call, it returns the cached result instead of recalculating. This is useful for optimizing expensive calculations when only the latest result needs to be cached, making it more memory-efficient than traditional memoization.

import * as 
import _
_ from 'radashi'

const 
const expensiveCalculation: (x: number, y: number) => number
expensiveCalculation = (
x: number
x: number, 
y: number
y: number): number => {
  
var console: Console
The console module provides a simple debugging console that is similar to the
JavaScript console mechanism provided by web browsers.
The module exports two specific components:

A Console class with methods such as console.log(), console.error() and console.warn() that can be used to write to any Node.js stream.
A global console instance configured to write to process.stdout and
process.stderr. The global console can be used without importing the node:console module.

Warning: The global console object's methods are neither consistently
synchronous like the browser APIs they resemble, nor are they consistently
asynchronous like all other Node.js streams. See the note on process I/O for
more information.
Example using the global console:
console.log('hello world');
// Prints: hello world, to stdout
console.log('hello %s', 'world');
// Prints: hello world, to stdout
console.error(new Error('Whoops, something bad happened'));
// Prints error message and stack trace to stderr:
//   Error: Whoops, something bad happened
//     at [eval]:5:15
//     at Script.runInThisContext (node:vm:132:18)
//     at Object.runInThisContext (node:vm:309:38)
//     at node:internal/process/execution:77:19
//     at [eval]-wrapper:6:22
//     at evalScript (node:internal/process/execution:76:60)
//     at node:internal/main/eval_string:23:3

const name = 'Will Robinson';
console.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to stderr
Example using the Console class:
const out = getStreamSomehow();
const err = getStreamSomehow();
const myConsole = new console.Console(out, err);

myConsole.log('hello world');
// Prints: hello world, to out
myConsole.log('hello %s', 'world');
// Prints: hello world, to out
myConsole.error(new Error('Whoops, something bad happened'));
// Prints: [Error: Whoops, something bad happened], to err

const name = 'Will Robinson';
myConsole.warn(`Danger ${name}! Danger!`);
// Prints: Danger Will Robinson! Danger!, to err
@see ― source
console.
Console.log(message?: any, ...optionalParams: any[]): void (+1 overload)
Prints to stdout with newline. Multiple arguments can be passed, with the
first used as the primary message and all additional used as substitution
values similar to printf(3)
(the arguments are all passed to util.format()).
const count = 5;
console.log('count: %d', count);
// Prints: count: 5, to stdout
console.log('count:', count);
// Prints: count: 5, to stdout
See util.format() for more information.
@since ― v0.1.100
log('Calculating...')
  return 
x: number
x + 
y: number
y
}

const 
const memoizedCalc: (x: number, y: number) => number
memoizedCalc = 
import _
_.
function memoLastCall<[x: number, y: number], number>(fn: (x: number, y: number) => number): (x: number, y: number) => number
Creates a memoized version of a function that caches only its most
recent call.
When the function is called with the same arguments as the previous
call, it returns the cached result instead of recalculating. This
is useful for optimizing expensive calculations when only the
latest result needs to be cached, making it more memory-efficient
than traditional memoization.
@see ― https://radashi.js.org/reference/curry/memoLastCall
@example 
const expensiveCalculation = (x: number, y: number): number => {
  console.log('Calculating...');
  return x + y;
};

const memoizedCalc = memoLastCall(expensiveCalculation);

console.log(memoizedCalc(2, 3));  // Outputs: "Calculating..." then 5
console.log(memoizedCalc(2, 3));  // Outputs: 5 (uses cached result)
console.log(memoizedCalc(3, 4));  // Outputs: "Calculating..." then 7
console.log(memoizedCalc(2, 3));  // Outputs: "Calculating..." then 5 (previous cache was overwritten)
@version ― 12.4.0
memoLastCall(
const expensiveCalculation: (x: number, y: number) => number
expensiveCalculation)

const memoizedCalc: (x: number, y: number) => number
memoizedCalc(2, 3) // Logs 'Calculating...'
const memoizedCalc: (x: number, y: number) => number
memoizedCalc(2, 3) // Returns cached result
const memoizedCalc: (x: number, y: number) => number
memoizedCalc(3, 4) // Logs 'Calculating...'
const memoizedCalc: (x: number, y: number) => number
memoizedCalc(2, 3) // Logs 'Calculating...'

Premature Optimization

It’s bad practice to reach for this function if you haven’t profiled your application and confirmed that the calculation you intend to memoize is the bottleneck.

Beyond performance gains, this function may come in handy if your calculation produces an object and you want memoized calls to return the same object reference for equality checks.