Conditionable::when multiple values

[epixian]

The when and unless helpers are incredibly valuable, except that they are limited to only true and false boolean values. Recently I found myself wishing for a PHP match-like construct allowing me to handle additional scenarios without invoking when for each.

I initially thought this could be named whenMatch however I think it will be confusing alongside the existing match and matchAll methods. Instead, maybe Conditionable::when() could be refactored to support an array of closures keyed by the values that would trigger them. I don't think PHP supports dynamic branching so we can't use the actual match function in PHP to implement this, but we could mimic its behavior:

Str::when($condition, [
    'yes' => fn (Stringable $str) => $str->lower(),
    'no' => fn (Stringable $str) => $str->upper()->finish('!'),
    'maybe' => fn (Stringable $str) => $str->markdown(),
]);

In the event the key is not found, the third parameter default closure would be executed.

Perhaps:

// Illuminate/Support/Traits/Conditionable.php

/**
 * Apply the callback if the given "value" is truthy or matches the key in an array of callbacks.
 *
 * @param  mixed  $value
 * @param  callable|callable[]  $callback
 * @param  callable|null  $default
 * @return $this|mixed
 */
public function when($value, $callback, $default = null)
{
    if (is_array($callback)) {
        if (!is_null($cb = Arr::get($callback, $value)) {
            return $cb($this, $value) ?: $this;
        } elseif ($default) {
            return $default($this, $value) ?: $this;
        }
    } elseif ($value) {
        return $callback($this, $value) ?: $this;
    } elseif ($default) {
        return $default($this, $value) ?: $this;
    }

    return $this;
}