C#•2mo ago

✅ Making a chess program. Why is this happening?

I don't understand this error and nothing online makes sense to me, so can I get a firsthand explanation of what I've done wrong? Or probably done wrong?

36 Replies

canton7•2mo ago

You've got another public struct Move somewhere in your code, in that same namespace

it’s raining outside•2mo ago

this is the only other search result when searching for public struct Move in vscode

canton7•2mo ago

Search for struct Move? Are you using source generators anywhere?

it’s raining outside•2mo ago

same result whats a source generator?

canton7•2mo ago

I'm guessing probably not then. Can we see the whole definition of Move?

it’s raining outside•2mo ago

see for yourself

GitHub

chess/MoveGeneration.cs at beta-testing · axololly/chess

A chess bot I made over the summer because my friends didn't want to go out with me. - axololly/chess

canton7•2mo ago

Not found: is your project private?

it’s raining outside•2mo ago

wait no its public i just got the link wrong on mobile rn ok works now missed the tree part of the URL

canton7•2mo ago

        [GeneratedRegex("^[a-h][1-8][a-h][1-8][qbrn]?$")]
        private static partial Regex MoveRegex();

        [GeneratedRegex("^[a-h][1-8][a-h][1-8][qbrn]?$")]
        private static partial Regex MoveRegex();

There we go. That GeneratedRegex attribute is a signal to a source generator to generate the other part partial part of that method at compile-time. See https://learn.microsoft.com/en-us/dotnet/standard/base-types/regular-expression-source-generators?pivots=dotnet-8-0 And for Move to have a partial method, it needs to be partial itself

it’s raining outside•2mo ago

can i make the method not partial? or does that break stuff?

canton7•2mo ago

It has to be partial in order for the GeneratedRegex machinery to work, see that link If you don't use GeneratedRegex then you don't need partial

it’s raining outside•2mo ago

ah ok. how do i use regex in C# without GeneratedRegex?

canton7•2mo ago

Just new Regex(...)?

it’s raining outside•2mo ago

ah okay oh yeah thats why i did this in the first place

Use 'GeneratedRegexAttribute' to generate the regular expression implementation at compile-time.

canton7•2mo ago

Yeah, it's prompting you to move to the source generator, which does produce a regex which is quicker to run at runtime (but does require partial, because it adds code to your class at compile-time)

it’s raining outside•2mo ago

should i keep it so it happens at compile time instead of runtime?

canton7•2mo ago

You can ignore / disable that prompt if you want It probably doesn't matter a huge amount either way

it’s raining outside•2mo ago

alright oops

canton7•2mo ago

(since your regex is quite small and simple)

it’s raining outside•2mo ago

fair enough

canton7•2mo ago

Btw, you can do value[1] - '1' rather than "12345678".IndexOf(value[1]). That avoids a linear search through the string

it’s raining outside•2mo ago

oh wait what you can subtract numerical versions of strings?

canton7•2mo ago

You can subtract chars

it’s raining outside•2mo ago

oh wow thats awesome thanks canton

canton7•2mo ago

(It's nothing to do with numbers stored as strings. Your "abcdefgh".IndexOf(value[0]) could also be written value[0] - 'a')

it’s raining outside•2mo ago

oh wow thanks man another question just quickly im using bitboards for my program. i mention this because i need to use bitwise operators on the struct. i also want to use && on the struct too

using System;

public struct Example
{
    public int Value;
    
    public Example(int x) => Value = x;
    
    public static implicit operator int(Example ex)  => ex.Value;
    public static implicit operator Example(int ex)  => new(ex);
    public static implicit operator bool(Example ex) => ex.Value != 0;
    
    public static Example operator &(Example first, Example second) => new(first.Value & second.Value);
    public static Example operator |(Example first, Example second) => new(first.Value | second.Value);
    
    public static bool operator true(Example ex) => ex.Value != 0;
    public static bool operator false(Example ex) => ex.Value == 0;
}
                    
class Program
{
    static void Main()
    {
        Example ex1, ex2;
        
        ex1 = 5;
        ex2 = 2;
        
        bool result = ex1 && ex2;
        
        Console.WriteLine(result);
    }
}

using System;

public struct Example
{
    public int Value;
    
    public Example(int x) => Value = x;
    
    public static implicit operator int(Example ex)  => ex.Value;
    public static implicit operator Example(int ex)  => new(ex);
    public static implicit operator bool(Example ex) => ex.Value != 0;
    
    public static Example operator &(Example first, Example second) => new(first.Value & second.Value);
    public static Example operator |(Example first, Example second) => new(first.Value | second.Value);
    
    public static bool operator true(Example ex) => ex.Value != 0;
    public static bool operator false(Example ex) => ex.Value == 0;
}
                    
class Program
{
    static void Main()
    {
        Example ex1, ex2;
        
        ex1 = 5;
        ex2 = 2;
        
        bool result = ex1 && ex2;
        
        Console.WriteLine(result);
    }
}

i have this example code and i want result to be true if ex1 and ex2 are non-zero values but this doesnt work removing the overload for & and | makes it work fine tho wait oh yeah if i overload it so that true (operator) returns ex.Value == 0 and false (operator) returns ex.Value != 0 that works just fine wait nevermind i fucked that up

canton7•2mo ago

What was the solution? I'm failing to spot it ><

if i overload it so that true (operator) returns ex.Value == 0 and false (operator) returns ex.Value != 0 that works just fine

In my reading of https://learn.microsoft.com/en-us/dotnet/csharp/language-reference/operators/true-false-operators, you've defined it correctly though? And if you flip the polarity of your true and false operators, then new Example(1) && new Example(0) returns true

it’s raining outside•2mo ago

ohh. if i did it correctly then theres no problem also

  |  Result: {kingMask && enemyQueenRook}");

  |  Result: {kingMask && enemyQueenRook}");

this is part of a print statement and it prints an empty bitboard despite that literally being a boolean

canton7•2mo ago

Yeah, but I would expect output which is different to what you're getting, so I still don't understand what's going on Oh, idiot It's because '5 & 2' is 0. So yes, your initial code does produce the correct result Because && is a short-circuiting &

it’s raining outside•2mo ago

ohhh 🤦‍♂️ so how do i fix that thne

canton7•2mo ago

You're trying to define && and & to have different semantics, but that's not how it works

it’s raining outside•2mo ago

https://cdn.discordapp.com/attachments/980924554711011408/1248521549875515402/4x.gif

canton7•2mo ago

Tbh, get rid of all the implicit crap and make some methods It'll be a lot more readable in a week/month, trust me 😛

it’s raining outside•2mo ago

unsettling emoji im too deep in the rabbit hole so you're saying i can't have && and & do different things? alright

bool isPossiblePin = (bool)kingMask && (bool)enemyQueenRook;

bool isPossiblePin = (bool)kingMask && (bool)enemyQueenRook;

i'll do this instead

canton7•2mo ago

But, if you get rid of the implicit stuff, that's kingMask != 0 && enemyQueenRook != 0. If you wrap things up a bit, that's !kingMask.IsEmpty && !enemyQueenRook.IsEmpty And IMO !kingMask.IsEmpty && !enemyQueenRook.IsEmpty is clearer than (bool)kingMask && (bool)enemyQueenRook

it’s raining outside•2mo ago

oh yeah i forgot i can do an .IsEmpty method. will do that 👍🏽

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✅ Making a chess program. Why is this happening?