Having fun with C# 11 raw string literals
The feature I’m most excited from freshly released C# 11 is raw string literals. You can read about the feature more here. In this blog post I’m going to try some limits. For fun. And learning.
If you think the same way I do, the obvious first question to ask is whether there’s some limit of number of double quotes at the beginning and end one can use… Let’s try that.
I created a console app to help me quickly generate the file (note the usage of another nifty feature, UTF-8 literals).
var prefix = """
namespace CrazyRawStringLiterals;
static class Generated
{
public static string String =
"""u8;
var suffix = """
;
}
"""u8;
var path = Path.Join(Path.GetDirectoryName(Environment.ProcessPath), "..", "..", "..", "..", "CrazyRawStringLiterals", "Generated.cs");
using (var fs = new FileStream(path, new FileStreamOptions() { Access = FileAccess.Write, Mode = FileMode.Truncate, BufferSize = 64 * 1024 }))
{
fs.Write(prefix);
for (var i = 0; i < count; i++)
fs.Write("\""u8);
fs.Write("\r\n"u8);
fs.Write("Test"u8);
fs.Write("\r\n"u8);
for (var i = 0; i < count; i++)
fs.Write("\""u8);
fs.Write(suffix);
Console.WriteLine($"File is {fs.Length:#,0} bytes.");
}
Depending on the count variable it will generate raw string literal with that number of double quotes. I started hot and went directly with int.MaxValue. Which failed because the file was too big for Roslyn. The maximum I could do was (int.MaxValue / 4) - 53. The compilation was fast, nothing interesting. In case you’d like to try - 52, you’ll end up in System.OverflowException: Arithmetic operation resulted in an overflow. at Microsoft.CodeAnalysis.CSharp.Syntax.InternalSyntax.SlidingTextWindow.MoreChars.
This left me unsatisfied. Nothing interesting happened. I was sad. But then I realized that any whitespace to the left of the closing double quotes will be removed from the string literal. That’s something to try!
Another quick generator app.
var prefix = """
namespace CrazyRawStringLiterals;
static class Generated
{
public static string String =
"""u8;
var suffix = """
;
}
"""u8;
var path = Path.Join(Path.GetDirectoryName(Environment.ProcessPath), "..", "..", "..", "..", "CrazyRawStringLiterals", "Generated.cs");
using (var fs = new FileStream(path, new FileStreamOptions() { Access = FileAccess.Write, Mode = FileMode.Truncate, BufferSize = 64 * 1024 }))
{
fs.Write(prefix);
fs.Write("\"\"\""u8);
fs.Write("\r\n"u8);
for (var i = 0; i < count; i++)
fs.Write(" "u8);
fs.Write("Test"u8);
fs.Write("\r\n"u8);
for (var i = 0; i < count; i++)
fs.Write(" "u8);
fs.Write("\"\"\""u8);
fs.Write(suffix);
Console.WriteLine($"File is {fs.Length:#,0} bytes.");
}
This proved to be more interesting. After I played with small-ish files, I realized it takes a lot of time to compile such files. I went for big, but safe, int.MaxValue / 10 and started the compilation. It took 2h39min on my machine to compile a simple console app using this file.
using CrazyRawStringLiterals;
Console.WriteLine(Generated.String);
Interesting? Maybe. On the other hand, you’re not going to type such file. And when generated, it can be, with little effort, pre-processed. But it was fun. 😃
