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Cake day: July 2nd, 2023

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  • JakenVeina@lemm.eetoStar Wars Memes@lemmy.worldAll of It.
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    2 days ago

    I always liked the theory that Han was intentionally using nonsense jargon, to see if Obi Wan would pick up on it. To see how gullible he is. And Obi Wan just went with it cause he was kinda desperate to get off the planet, what with the stormtroopers snooping around looking for the droids.


  • I’m gonna hazard a guess, just cause I’m curious, that you’re coming from JavaScript.

    Regardless, the answer’s basically the same across all similar languages where this question makes sense. That is, languages that are largely, if not completely, object-oriented, where memory is managed for you.

    Bottom line, object allocation is VERY expensive. Generally, objects are allocated on a heap, so the allocation process itself, in its most basic form, involves walking some portion of a linked list to find an available heap block, updating a header or other info block to track that the block is now in use, maybe sub-dividing the block to avoid wasting space, any making any updates that might be necessary to nodes of the linked list that we traversed.

    THEN, we have to run similar operations later for de-allocation. And if we’re talking about a memory-managed language, well, that means running a garbage collector algorithm, periodically, that needs to somehow inspect blocks that are in use to see if they’re still in use, or can be automatically de-allocated. The most common garbage-collector I know of involves tagging all references within other objects, so that the GC can start at the “root” objects and walk the entire tree of references within references, in order to find any that are orphaned, and identify them as collectable.

    My bread and butter is C#, so let’s look at an actual example.

    public class MyMutableObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    }
    
    public record MyImmutableObject
    {
        public required ulong Id { get; init; }
    
        public required string Name { get; init; }
    }
    
    _immutableInstance = new()
    {
        Id      = 1,
        Name    = "First"
    };
    
    _mutableInstance = new()
    {
        Id      = 1,
        Name    = "First"
    };
    
    [Benchmark(Baseline = true)]
    public MyMutableObject MutableEdit()
    {
        _mutableInstance.Name = "Second";
    
        return _mutableInstance;
    }
    
    [Benchmark]
    public MyImmutableObject ImmutableEdit()
        => _immutableInstance with
        {
            Name = "Second"
        };
    
    Method Mean Error StdDev Ratio RatioSD Gen0 Allocated Alloc Ratio
    MutableEdit 1.080 ns 0.0876 ns 0.1439 ns 1.02 0.19 - - NA
    ImmutableEdit 8.282 ns 0.2287 ns 0.3353 ns 7.79 1.03 0.0076 32 B NA

    Even for the most basic edit operation, immutable copying is slower by more than 7 times, and (obviously) allocates more memory, which translates to more cost to be spent on garbage collection later.

    Let’s scale it up to a slightly-more realistic immutable data structure.

    public class MyMutableParentObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    
        public required MyMutableChildObject Child { get; set; }
    }
    
    public class MyMutableChildObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    
        public required MyMutableGrandchildObject FirstGrandchild { get; set; }
                
        public required MyMutableGrandchildObject SecondGrandchild { get; set; }
                
        public required MyMutableGrandchildObject ThirdGrandchild { get; set; }
    }
    
    public class MyMutableGrandchildObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    }
    
    public record MyImmutableParentObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    
        public required MyImmutableChildObject Child { get; set; }
    }
    
    public record MyImmutableChildObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    
        public required MyImmutableGrandchildObject FirstGrandchild { get; set; }
                
        public required MyImmutableGrandchildObject SecondGrandchild { get; set; }
                
        public required MyImmutableGrandchildObject ThirdGrandchild { get; set; }
    }
    
    public record MyImmutableGrandchildObject
    {
        public required ulong Id { get; set; }
    
        public required string Name { get; set; }
    }
    
    _immutableTree = new()
    {
        Id      = 1,
        Name    = "Parent",
        Child   = new()
        {
            Id                  = 2,
            Name                = "Child",
            FirstGrandchild     = new()
            {
                Id      = 3,
                Name    = "First Grandchild"
            },
            SecondGrandchild    = new()
            {
                Id      = 4,
                Name    = "Second Grandchild"
            },
            ThirdGrandchild     = new()
            {
                Id      = 5,
                Name    = "Third Grandchild"
            },
        }
    };
    
    _mutableTree = new()
    {
        Id      = 1,
        Name    = "Parent",
        Child   = new()
        {
            Id                  = 2,
            Name                = "Child",
            FirstGrandchild     = new()
            {
                Id      = 3,
                Name    = "First Grandchild"
            },
            SecondGrandchild    = new()
            {
                Id      = 4,
                Name    = "Second Grandchild"
            },
            ThirdGrandchild     = new()
            {
                Id      = 5,
                Name    = "Third Grandchild"
            },
        }
    };
    
    [Benchmark(Baseline = true)]
    public MyMutableParentObject MutableEdit()
    {
        _mutableTree.Child.SecondGrandchild.Name = "Second Grandchild Edited";
    
        return _mutableTree;
    }
    
    [Benchmark]
    public MyImmutableParentObject ImmutableEdit()
        => _immutableTree with
        {
            Child = _immutableTree.Child with
            {
                SecondGrandchild = _immutableTree.Child.SecondGrandchild with
                {
                    Name = "Second Grandchild Edited"
                }
            }
        };
    
    Method Mean Error StdDev Ratio RatioSD Gen0 Allocated Alloc Ratio
    MutableEdit 1.129 ns 0.0840 ns 0.0825 ns 1.00 0.10 - - NA
    ImmutableEdit 32.685 ns 0.8503 ns 2.4534 ns 29.09 2.95 0.0306 128 B NA

    Not only is performance worse, but it drops off exponentially, as you scale out the size of your immutable structures.


    Now, all this being said, I myself use the immutable object pattern FREQUENTLY, in both C# and JavaScript. There’s a lot of problems you encounter in business logic that it solves really well, and it’s basically the ideal type of data structure for use in reactive programming, which is extremely effective for building GUIs. In other words, I use immutable objects a ton when I’m building out the business layer of a UI, where data is king. If I were writing code within any of the frameworks I use to BUILD those UIs (.NET, WPF, ReactiveExtensions) you can bet I’d be using immutable objects way more sparingly.










  • I’m not sure which ones he was into at 4yo specifically, but my son’s Switch favorites include…

    Super Mario Odyssey Mario + Rabbids: Kingdom Battle Celeste Minecraft Yoshi’s Crafted World Letterquest Big Brain Academy NES Arcade SNES Arcade

    Of those, the ones I would say mught meet your super-chill criteria are…

    Super Mario Odyssey (yeah, you can die, but you just respawn and can spend tons of time just running around aimlessly) Celeste (normally not, but there’s a lovely Assist Mode) Yoshi’s Crafted World (there’s a no-fail mode) Big Brain Academy (if they can handle being scored on things, without taking it too seriously).









  • He alluded to it in the first video, and I think it’s spot on.

    They ended up with an “inventory problem”. Which is to say, some business major in the company somewhere, or a consultant or whatever saw that they were spending money to store it all, and said “A company’s assets should never cost money, they should MAKE money” or some such business speak. Ultimately that translated into every layer of the business being instructed to prioritize using that that old inventory, somehow, or pushing it to customers.

    “People don’t really want to buy all this older hardware off of us, but we can convince people who don’t know any better to rent it.”

    “We don’t have enough 4090s to keep up with demand for these high-end rentals, but we’re sure as hell not buying more when we have all these perfectly-good 4080s lying around.”