Split core code into ly-core library

Signed-off-by: AnErrupTion <anerruption@disroot.org>

ly-core/src/SharedError.zig

@@ -0,0 +1,39 @@
+const std = @import("std");
+
+const ErrInt = std.meta.Int(.unsigned, @bitSizeOf(anyerror));
+
+const ErrorHandler = packed struct {
+    has_error: bool = false,
+    err_int: ErrInt = 0,
+};
+
+const SharedError = @This();
+
+data: []align(std.heap.page_size_min) u8,
+
+pub fn init() !SharedError {
+    const data = try std.posix.mmap(null, @sizeOf(ErrorHandler), std.posix.PROT.READ | std.posix.PROT.WRITE, .{ .TYPE = .SHARED, .ANONYMOUS = true }, -1, 0);
+
+    return .{ .data = data };
+}
+
+pub fn deinit(self: *SharedError) void {
+    std.posix.munmap(self.data);
+}
+
+pub fn writeError(self: SharedError, err: anyerror) void {
+    var buf_stream = std.io.fixedBufferStream(self.data);
+    const writer = buf_stream.writer();
+    writer.writeStruct(ErrorHandler{ .has_error = true, .err_int = @intFromError(err) }) catch {};
+}
+
+pub fn readError(self: SharedError) ?anyerror {
+    var buf_stream = std.io.fixedBufferStream(self.data);
+    const reader = buf_stream.reader();
+    const err_handler = try reader.readStruct(ErrorHandler);
+
+    if (err_handler.has_error)
+        return @errorFromInt(err_handler.err_int);
+
+    return null;
+}