deep_copy.hhs

/**
 * @author 
 * @param input - the input to make a deep copy of 
 * @returns - a new copy of the original input with a different reference
 * 
 *  This recursive function is made for cloning arrays in a deep manner since javascript doesn't have a way to do it. All common ways to copy is shallow and that
 *  causes a lot of issues for functions that modify the input or a reference to the input 
 */

 function deep_copy(items) {

    *import math:is_number 

    // wrong argument number
    if (arguments.length === 0) {
        throw new Error('Exception occurred in deep_copy - no argument given');
    }
    else if (arguments.length > 1) {
        throw new Error('Exception occurred in deep_copy - wrong argument number');
    }

    // type check
    if (!(Array.isArray(items)) && !(items instanceof Mat) && !(items instanceof Tensor) && !(is_number(items))) {
        throw new Error('Exception occurred in deep_copy - input is not a Mat, Tensor or JS Array');
    }
    
    // for loop is faster, will replace with it later
    //below is causing items.map is not a function issue again?
    //return items.map(item => Array.isArray(item) ? deep_copy(item) : item);

    //support for numbers in case we're deep copying numbers in general cases 
    if (is_number(items)) {
        return items;
    }

    else {

        return items.map(item => Array.isArray(item) ? deep_copy(item) : item);

    }
}