Add endianness-specific reading functions.

src/coral/bytes.zig

@@ -21,7 +21,7 @@ pub const ReadOnlySpan = struct {
     }
 };
 
-pub const ReadWriteError = error{IncompleteWrite};
+pub const ReadWriteError = error{ IncompleteRead, IncompleteWrite };
 
 pub const Readable = coral.Callable(usize, &.{[]u8});
 
@@ -139,6 +139,47 @@ pub fn printFormatted(buffer: [:0]u8, comptime format: []const u8, args: anytype
     return buffer[0..len :0];
 }
 
+pub fn readBig(input: Readable, comptime T: type) ReadWriteError!T {
+    var buffer: [@sizeOf(T)]u8 align(@alignOf(T)) = undefined;
+
+    if (input.call(.{&buffer}) != buffer.len) {
+        return error.IncompleteRead;
+    }
+
+    switch (builtin.cpu.arch.endian()) {
+        .big => {},
+
+        .little => {
+            std.mem.byteSwapAllFields(T, @ptrCast(&buffer));
+        },
+    }
+
+    return std.mem.bytesToValue(T, &buffer);
+}
+
+pub fn readLittle(input: Readable, comptime T: type) ReadWriteError!T {
+    var buffer: [@sizeOf(T)]u8 = undefined;
+
+    if (input.call(.{&buffer}) != buffer.len) {
+        return error.IncompleteRead;
+    }
+
+    switch (builtin.cpu.arch.endian()) {
+        .big => {
+            std.mem.byteSwapAllFields(T, &buffer);
+        },
+
+        .little => {},
+    }
+
+    return std.mem.bytesToValue(T, &buffer);
+}
+
+pub const readNative = switch (builtin.cpu.arch.endian()) {
+    .little => readLittle,
+    .big => readBig,
+};
+
 pub fn span(ptr: anytype) Span(@TypeOf(ptr)) {
     return .{
         .bytes = switch (@typeInfo(@TypeOf(ptr)).pointer.size) {