C#

Rob Philpott wrote:

Firstly, what is it that is being switched?

Rob Philpott wrote:

So then you get into the realms of how similar are the strings?

Jörgen Andersson wrote:

So one of the larger switches will be 60+ words where the first difference is at the 19th position.

if (input.Length >= 19)
{
    return input[18] switch
    {
        'A' => ProcessA(input.AsSpan(19)),
        'B' => ProcessB(input.AsSpan(19)),
        ...
    };
}

return input switch
{
    [_, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, _, 'A', ..] => ProcessA(input.AsSpan(19)),
    ...
};

Rob Philpott wrote:

so is it that you've got these large files to process and you're trying to optimise the switching (state changes) for speed

Rob Philpott wrote:

Which approach are you using at the moment

Rob Philpott wrote:

Does this mean the switch/state change logic is fixed in advance?

Quote: ListDictionary Class[^]

This is a simple implementation of IDictionary using a singly linked list. It is smaller and faster than a Hashtable if the number of elements is 10 or less. This should not be used if performance is important for large numbers of elements.

Jörgen Andersson wrote:

It's strings.

Jörgen Andersson wrote:

And as the files

Jörgen Andersson wrote:

be worth some optimization.

jschell wrote:

One advantage to C++ (and C) is that you can force a string to be treated as a numeric. So a value like "ABCD" can be cast directly to a 32 bit unsigned integer. And of course you could use 64 bit also.

ReadOnlySpan<char> input = "ABCD"; // For .NET Framework / Standard 2.0, you'll need to add ".AsSpan()" here.
ReadOnlySpan<byte> bytes = System.Runtime.InteropServices.MemoryMarshal.AsBytes(input);
int value = System.Runtime.InteropServices.MemoryMarshal.Read<int>(bytes);
// value == 4325441

Richard Deeming wrote:

C#

ReadOnlySpan<char> input = "ABCD"; 
ReadOnlySpan<byte> bytes = System.Runtime.InteropServices.MemoryMarshal.AsBytes(input);
int value = System.Runtime.InteropServices.MemoryMarshal.Read<int>(bytes);

jschell wrote:

So a value like "ABCD" can be cast directly to a 32 bit unsigned integer.

ReadOnlySpan<byte> bytes = "ABCD"u8;
int value = System.Runtime.InteropServices.MemoryMarshal.Read<int>(bytes);
// 0x44434241

ReadOnlySpan<byte> bytes = "ABCD"u8;

P.... didn’t save Editor3D_Render_Control for 2022 MS VStuio