Non-conventional C# multi-dimensional arrays generated

[Anatoly03]

Describe the bug

In C#, a multi-dimensional array is declared with commas in-between the square brackets ([,]), and not conventionally with square brackets stacked ([][]).

bebop/Core/Generators/CSharp/CSharpGenerator.cs

Lines 1341 to 1342 in 2108a61

	ArrayType at =>
	$"{(at.MemberType is ArrayType ? $"{TypeName(at.MemberType, arraySizeVar)}[]" : $"{TypeName(at.MemberType)}[{arraySizeVar}]")}",

This line should not append the type recursively to be (recursive call)[], but instead read out the dimension of the array, and write commas by formula by pseudo-code"[" + ",".repeat(dimension - 1) + "]".
A clear and concise description of what the bug is.

To Reproduce

struct FooBar {
    uint8[][] foo;
    string[][][] bar;
}

Expected behavior

The generated C# code should have multi-dimensional arrays with the respective commas [,] and [,,]

Screenshots / Snippets

// struct WorldInit {
//     uint16 width;
//     uint16 height;
//     BlockData[][] background;
//     BlockData[][] foreground;
// }
public partial class WorldInit : global::Bebop.Runtime.BaseBebopRecord, global::Bebop.Runtime.IDecodable<WorldInit>, global::System.IEquatable<WorldInit> {
    ...
    public global::PixelWalker.MessageLibrary.BlockData[][] Background { get; init; }
    [global::System.Diagnostics.CodeAnalysis.NotNull, global::System.Diagnostics.CodeAnalysis.DisallowNull]
    public global::PixelWalker.MessageLibrary.BlockData[][] Foreground { get; init; }
    ...
}

Bebop info:

• Version: 3.0.14
• Runtime: .NET

    <ItemGroup>
      <PackageReference Include="bebop" Version="3.0.14" />
      <PackageReference Include="bebop-tools" Version="3.0.14">
        <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
        <PrivateAssets>all</PrivateAssets>
      </PackageReference>
      <Bebop Include="**/*.bop" OutputDir="./Models/" OutputFile="Models.g.cs" Namespace="PixelWalker.MessageLibrary" />
    </ItemGroup>

Desktop (please complete the following information):

• OS: macOS-Intel
• Version Ventura

[andrewmd5]

Thanks for opening this issue. Bebop only supports jagged arrays and has no concept for multi-dimensional arrays.

While C# does support multi-dimensional arrays, languages Bebop also supports such as Rust and Dart do not. So we only generate data structures that every language can support.

[Anatoly03]

Thanks for replying. If I understand right, the bebop generators are language specific, so this can be customized? A simple recursive function that stops on a non array can yield the array dimensions. Could this be implemented in the lines mentioned above?

bebop/Core/Generators/CSharp/CSharpGenerator.cs

Lines 1312 to 1348 in 2108a61

	/// <summary>
	/// Generate a C# type name for the given <see cref="TypeBase"/>.
	/// </summary>
	/// <param name="type">The field type to generate code for.</param>
	/// <param name="arraySizeVar">A variable name that will be formatted into the array initializer</param>
	/// <returns>The C# type name.</returns>
	private string TypeName(in TypeBase type, string arraySizeVar = "")
	{
	return type switch
	{
	ScalarType st => st.BaseType switch
	{
	BaseType.Bool => "bool",
	BaseType.Byte => "byte",
	BaseType.UInt32 => "uint",
	BaseType.Int32 => "int",
	BaseType.Float32 => "float",
	BaseType.Float64 => "double",
	BaseType.String => "string",
	BaseType.Guid => "global::System.Guid",
	BaseType.UInt16 => "ushort",
	BaseType.Int16 => "short",
	BaseType.UInt64 => "ulong",
	BaseType.Int64 => "long",
	BaseType.Date => "global::System.DateTime",
	_ => throw new ArgumentOutOfRangeException(st.BaseType.ToString())
	},
	ArrayType { MemberType: ScalarType { BaseType: BaseType.Byte } } at =>
	$"{ImmutableArrayType}<{TypeName(at.MemberType)}>",
	ArrayType at =>
	$"{(at.MemberType is ArrayType ? $"{TypeName(at.MemberType, arraySizeVar)}[]" : $"{TypeName(at.MemberType)}[{arraySizeVar}]")}",
	MapType mt =>
	$"global::System.Collections.Generic.Dictionary<{TypeName(mt.KeyType)}, {TypeName(mt.ValueType)}>",
	DefinedType dt => PrefixNamespace($"{dt.Name.ToPascalCase()}"),
	_ => throw new InvalidOperationException($"GetTypeName: {type}")
	};
	}

Here's an example of how this function could look like:

private int ArrayDimension(in TypeBase type)
{
    return type switch
    {
        ArrayType at => 1 + ArrayDimension(at.MemberType),
        _ => 0
    };
}

[Emalton]

@andrewmd5 We really could use this. Crippling bebop wouldn't be ideal, as both languages that we're using support multi-dimensional arrays. Perhaps a warning that this is only supported on some languages in the readme or something would be best.