random-js
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ckknight
Force value to either min or max
I know this might be an odd question for a random library but, is there any way of forcing an engine to return the min or max value when using integer or real?
e.g.:
// force this to always return the min, 1
integer(1, 4);
// force this to always return the max, 4
integer(1, 4);
I've looked at creating a custom engine, and if the next() method returns 0 it seems to always return the min value:
const engine = {
next() {
return 0;
},
};
integer(1, 4); // returns 1
integer(1, 4); // returns 1
integer(1, 4); // returns 1
I'm assuming it works by returning the number from the range, by index of the response from next(). But I can't find a way of forcing the max value.
I know this is an odd request, so it's unlikely anyone else wants to achieve this but, just in case, this was my solution;
Min engine
Always returns the lowest possible value.
/**
* Engine that always returns the minimum value.
*
* @type {{next(): number}}
*/
const minEngine = {
/**
* Returns the minimum number index, `0`
*
* @returns {number}
*/
next() {
return 0;
},
};
E.g.
const random = new Random(minEngine);
random.integer(1, 4); // returns 1
random.integer(10, 300); // returns 10
random.integer(-55, -12); // returns -55
Max engine
Always returns the maximum value.
/**
* Engine that always returns the maximum value.
*
* @type {{next(): number, range: number[]}}
*/
const maxEngine = {
/**
* The min / max number range (e.g. `[1, 10]`).
*
* This _must_ be set for the `next()` method to return the correct last index.
*
* @example
* maxEngine.range = [1, 10];
*
* @type {number[]}
*/
range: [],
/**
* Returns the maximum number index for the range
*
* @returns {number}
*/
next() {
// calculate the index of the max number
return this.range[1] - this.range[0];
},
};
The max and minimum values must be set against the maxEngine.range before use.
const random = new Random(maxEngine);
maxEngine.range = [1, 4];
random.integer(1, 4); // returns 4
maxEngine.range = [10, 300];
random.integer(10, 300); // returns 300
maxEngine.range = [-55, -12];
random.integer(-55, -12); // returns -12
It might seem a bit pointless, if I'm having to provide the min and max range, but I'm using it where I'm providing the data programatically, where I don't know what the values are in advance.
I'm not sure if this works with .real() but I only needed it to work for .integer().
I would be interested to know if there's a better way of achieving this (e.g. if random-js can provide the max index so I don't need to calculate it, or just the min/max values so they don't need to be specified manually).
It would probably make more sense to make a max/min function that hooks into the random.integer/random.die/random.real and takes the entire call as an argument @ckknight would this be a possibility for v3.0.0?
