make Origin::ZERO the Default::default()

examples/announce.rs

@@ -40,8 +40,8 @@ fn main() {
 
     let text = cli.text.join("\n");
     let command = CharGridCommand {
-        origin: Origin::ZERO,
         grid: CharGrid::wrap_str(TILE_WIDTH, &text),
+        origin: Origin::ZERO,
     };
     connection.send(command).expect("sending text failed");
 }

examples/brightness_tester.rs

@@ -18,8 +18,8 @@ fn main() {
     bitmap.fill(true);
 
     let command = BitmapCommand {
-        origin: Origin::ZERO,
         bitmap,
+        origin: Origin::ZERO,
         compression: CompressionCode::default(),
     };
     connection.send(command).expect("send failed");

examples/game_of_life.rs

@@ -23,8 +23,8 @@ fn main() {
 
     loop {
         let command = BitmapCommand {
-            origin: Origin::ZERO,
             bitmap: field.clone(),
+            origin: Origin::ZERO,
             compression: CompressionCode::default(),
         };
         connection.send(command).expect("could not send");

examples/random_brightness.rs

@@ -29,8 +29,8 @@ fn main() {
         filled_grid.fill(true);
 
         let command = BitmapCommand {
-            origin: Origin::ZERO,
             bitmap: filled_grid,
+            origin: Origin::ZERO,
             compression: CompressionCode::default(),
         };
         connection.send(command).expect("send failed");

examples/websocket.rs

@@ -12,8 +12,8 @@ fn main() {
     pixels.fill(true);
 
     let command = BitmapCommand {
-        origin: Origin::ZERO,
         bitmap: pixels,
+        origin: Origin::ZERO,
         compression: CompressionCode::default(),
     };
     connection.send(command).unwrap();

examples/wiping_clear.rs

@@ -33,8 +33,8 @@ fn main() {
         }
 
         let command = BitmapCommand {
-            origin: Origin::ZERO,
             bitmap: enabled_pixels.clone(),
+            origin: Origin::ZERO,
             compression: CompressionCode::default(),
         };
         connection

src/brightness.rs

@@ -18,6 +18,7 @@ use rand::{
 /// let result = connection.send(BrightnessCommand::from(b));
 /// ```
 #[derive(Debug, Copy, Clone, PartialEq, Eq, Ord, PartialOrd)]
+#[repr(transparent)]
 pub struct Brightness(u8);
 
 impl From<Brightness> for u8 {

src/commands/bitmap.rs

@@ -1,8 +1,10 @@
 use crate::{
-    command_code::CommandCode, commands::TryFromPacketError,
-    compression::into_compressed, compression::into_decompressed, Bitmap,
-    CompressionCode, Grid, Header, Origin, Packet, Pixels, TypedCommand,
-    TILE_SIZE,
+    command_code::CommandCode,
+    commands::errors::{TryFromPacketError, TryIntoPacketError},
+    compression::into_compressed,
+    compression::into_decompressed,
+    Bitmap, CompressionCode, Grid, Header, Origin, Packet, Pixels,
+    TypedCommand, TILE_SIZE,
 };
 
 /// Overwrites a rectangular region of pixels.
@@ -28,25 +30,28 @@ use crate::{
 ///
 /// connection.send(command).expect("send failed");
 /// ```
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct BitmapCommand {
-    /// where to start drawing the pixels
-    pub origin: Origin<Pixels>,
     /// the pixels to send
     pub bitmap: Bitmap,
+    /// where to start drawing the pixels
+    pub origin: Origin<Pixels>,
     /// how to compress the command when converting to packet
     pub compression: CompressionCode,
 }
 
-impl From<BitmapCommand> for Packet {
-    fn from(value: BitmapCommand) -> Self {
+impl TryFrom<BitmapCommand> for Packet {
+    type Error = TryIntoPacketError;
+
+    fn try_from(value: BitmapCommand) -> Result<Self, Self::Error> {
         assert_eq!(value.origin.x % 8, 0);
         assert_eq!(value.bitmap.width() % 8, 0);
 
-        let tile_x = (value.origin.x / TILE_SIZE) as u16;
-        let tile_w = (value.bitmap.width() / TILE_SIZE) as u16;
-        let pixel_h = value.bitmap.height() as u16;
-        let payload = into_compressed(value.compression, value.bitmap.into());
+        let tile_x = (value.origin.x / TILE_SIZE).try_into()?;
+        let tile_w = (value.bitmap.width() / TILE_SIZE).try_into()?;
+        let pixel_h = value.bitmap.height().try_into()?;
+        let payload = into_compressed(value.compression, value.bitmap.into())
+            .ok_or(TryIntoPacketError::CompressionFailed)?;
         let command = match value.compression {
             CompressionCode::Uncompressed => {
                 CommandCode::BitmapLinearWinUncompressed
@@ -61,16 +66,16 @@ impl From<BitmapCommand> for Packet {
             CompressionCode::Zstd => CommandCode::BitmapLinearWinZstd,
         };
 
-        Packet {
+        Ok(Packet {
             header: Header {
                 command_code: command.into(),
                 a: tile_x,
-                b: value.origin.y as u16,
+                b: value.origin.y.try_into()?,
                 c: tile_w,
                 d: pixel_h,
             },
             payload,
-        }
+        })
     }
 }
 
@@ -162,8 +167,11 @@ impl BitmapCommand {
 mod tests {
     use super::*;
     use crate::command_code::CommandCode;
+    use crate::commands::tests::TestImplementsCommand;
     use crate::*;
 
+    impl TestImplementsCommand for BitmapCommand {}
+
     #[test]
     fn command_code() {
         assert_eq!(
@@ -188,7 +196,8 @@ mod tests {
                 bitmap: Bitmap::new(8, 8).unwrap(),
                 compression: *compression,
             }
-            .into();
+            .try_into()
+            .unwrap();
 
             let Packet {
                 header,

src/commands/bitmap_legacy.rs

@@ -1,6 +1,6 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code_only,
-    commands::TryFromPacketError, Packet, TypedCommand,
+    commands::errors::TryFromPacketError, Packet, TypedCommand,
 };
 use std::fmt::Debug;
 
@@ -17,7 +17,7 @@ use std::fmt::Debug;
 /// # #[allow(deprecated)]
 /// connection.send(BitmapLegacyCommand).unwrap();
 /// ```
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 #[deprecated]
 pub struct BitmapLegacyCommand;
 
@@ -54,8 +54,12 @@ impl From<BitmapLegacyCommand> for TypedCommand {
 #[allow(deprecated)]
 mod tests {
     use super::*;
-    use crate::commands::tests::round_trip;
-    use crate::Header;
+    use crate::{
+        commands::tests::{round_trip, TestImplementsCommand},
+        Header
+    };
+
+    impl TestImplementsCommand for BitmapLegacyCommand {}
 
     #[test]
     fn invalid_fields() {

src/commands/bitvec.rs

@@ -1,8 +1,7 @@
-use crate::compression::into_compressed;
 use crate::{
-    command_code::CommandCode, commands::TryFromPacketError,
-    compression::into_decompressed, BitVec, CompressionCode, Header, Offset,
-    Packet, TypedCommand,
+    command_code::CommandCode, commands::errors::TryFromPacketError,
+    compression::into_compressed, compression::into_decompressed, BitVec,
+    CompressionCode, Header, Offset, Packet, TryIntoPacketError, TypedCommand,
 };
 
 /// Binary operations for use with the [BitVecCommand] command.
@@ -31,40 +30,43 @@ pub enum BinaryOperation {
 /// For example, [BinaryOperation::Or] can be used to turn on some pixels without affecting other pixels.
 ///
 /// The contained [BitVec] is always uncompressed.
-#[derive(Clone, PartialEq, Debug)]
+#[derive(Clone, PartialEq, Debug, Eq)]
 pub struct BitVecCommand {
-    /// where to start overwriting pixel data
-    pub offset: Offset,
     /// the pixels to send to the display as one long row
     pub bitvec: BitVec,
+    /// where to start overwriting pixel data
+    pub offset: Offset,
     /// The operation to apply on the display per bit comparing old and new state.
     pub operation: BinaryOperation,
     /// how to compress the command when converting to packet
     pub compression: CompressionCode,
 }
 
-impl From<BitVecCommand> for Packet {
-    fn from(command: BitVecCommand) -> Self {
-        let command_code = match command.operation {
+impl TryFrom<BitVecCommand> for Packet {
+    type Error = TryIntoPacketError;
+
+    fn try_from(value: BitVecCommand) -> Result<Self, Self::Error> {
+        let command_code = match value.operation {
             BinaryOperation::Overwrite => CommandCode::BitmapLinear,
             BinaryOperation::And => CommandCode::BitmapLinearAnd,
             BinaryOperation::Or => CommandCode::BitmapLinearOr,
             BinaryOperation::Xor => CommandCode::BitmapLinearXor,
         };
 
-        let payload: Vec<_> = command.bitvec.into();
-        let length = payload.len() as u16;
-        let payload = into_compressed(command.compression, payload);
-        Packet {
+        let payload: Vec<_> = value.bitvec.into();
+        let length = payload.len().try_into()?;
+        let payload = into_compressed(value.compression, payload)
+            .ok_or(TryIntoPacketError::CompressionFailed)?;
+        Ok(Packet {
             header: Header {
                 command_code: command_code.into(),
-                a: command.offset as u16,
+                a: value.offset.try_into()?,
                 b: length,
-                c: command.compression.into(),
+                c: value.compression.into(),
                 d: 0,
             },
             payload,
-        }
+        })
     }
 }
 
@@ -135,9 +137,11 @@ impl From<BitVecCommand> for TypedCommand {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::commands::tests::round_trip;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
     use crate::{commands, Bitmap, BitmapCommand, Origin};
 
+    impl TestImplementsCommand for BitVecCommand {}
+
     #[test]
     fn command_code() {
         assert_eq!(
@@ -193,7 +197,8 @@ mod tests {
                 compression: *compression,
                 operation: BinaryOperation::Overwrite,
             }
-            .into();
+            .try_into()
+            .unwrap();
             let Packet {
                 header,
                 mut payload,
@@ -223,7 +228,8 @@ mod tests {
             compression: CompressionCode::Uncompressed,
             operation: BinaryOperation::Or,
         }
-        .into();
+        .try_into()
+        .unwrap();
         let Header {
             command_code: command,
             a: offset,
@@ -255,7 +261,8 @@ mod tests {
             compression: CompressionCode::Uncompressed,
             operation: BinaryOperation::And,
         }
-        .into();
+        .try_into()
+        .unwrap();
         let Header {
             command_code: command,
             a: offset,
@@ -287,7 +294,8 @@ mod tests {
             compression: CompressionCode::Uncompressed,
             operation: BinaryOperation::Xor,
         }
-        .into();
+        .try_into()
+        .unwrap();
         let Header {
             command_code: command,
             a: offset,

src/commands/brightness.rs

@@ -1,6 +1,7 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code,
-    commands::TryFromPacketError, Brightness, Header, Packet, TypedCommand,
+    commands::errors::TryFromPacketError, Brightness, Header, Packet,
+    TypedCommand,
 };
 
 /// Set the brightness of all tiles to the same value.
@@ -13,7 +14,7 @@ use crate::{
 /// let command = BrightnessCommand { brightness: Brightness::MAX };
 /// connection.send(command).unwrap();
 /// ```
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct BrightnessCommand {
     /// the brightness to set all pixels to
     pub brightness: Brightness,
@@ -85,12 +86,14 @@ impl From<Brightness> for BrightnessCommand {
 #[cfg(test)]
 mod tests {
     use crate::command_code::CommandCode;
-    use crate::commands::tests::round_trip;
+    use crate::commands::errors::TryFromPacketError;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
     use crate::{
-        commands, Brightness, BrightnessCommand, Header, Packet,
-        TryFromPacketError, TypedCommand,
+        commands, Brightness, BrightnessCommand, Header, Packet, TypedCommand,
     };
 
+    impl TestImplementsCommand for BrightnessCommand {}
+
     #[test]
     fn brightness_as_command() {
         assert_eq!(

src/commands/brightness_grid.rs

@@ -1,25 +1,27 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code,
-    commands::TryFromPacketError, BrightnessGrid, ByteGrid, Header, Origin,
-    Packet, Tiles, TypedCommand,
+    commands::errors::TryFromPacketError, BrightnessGrid, ByteGrid, Header,
+    Origin, Packet, Tiles, TryIntoPacketError, TypedCommand,
 };
 
 /// Set the brightness of individual tiles in a rectangular area of the display.
-#[derive(Clone, PartialEq, Debug)]
+#[derive(Clone, PartialEq, Debug, Eq)]
 pub struct BrightnessGridCommand {
-    /// which tile the brightness rectangle should start
-    pub origin: Origin<Tiles>,
     /// the brightness values per tile
     pub grid: BrightnessGrid,
+    /// which tile the brightness rectangle should start
+    pub origin: Origin<Tiles>,
 }
 
-impl From<BrightnessGridCommand> for Packet {
-    fn from(value: BrightnessGridCommand) -> Self {
-        Packet::origin_grid_to_packet(
+impl TryFrom<BrightnessGridCommand> for Packet {
+    type Error = TryIntoPacketError;
+
+    fn try_from(value: BrightnessGridCommand) -> Result<Self, Self::Error> {
+        Ok(Packet::origin_grid_to_packet(
             value.origin,
             value.grid,
             CommandCode::CharBrightness,
-        )
+        )?)
     }
 }
 
@@ -74,12 +76,15 @@ impl From<BrightnessGridCommand> for TypedCommand {
 
 #[cfg(test)]
 mod tests {
-    use crate::commands::tests::round_trip;
+    use crate::commands::errors::TryFromPacketError;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
     use crate::{
         commands, BrightnessGrid, BrightnessGridCommand, Origin, Packet,
-        TryFromPacketError, TypedCommand,
+        TypedCommand,
     };
 
+    impl TestImplementsCommand for BrightnessGridCommand {}
+
     #[test]
     fn round_trip_char_brightness() {
         round_trip(
@@ -98,7 +103,7 @@ mod tests {
             origin: Origin::ZERO,
             grid,
         };
-        let mut packet: Packet = command.into();
+        let mut packet: Packet = command.try_into().unwrap();
         let slot = packet.payload.get_mut(1).unwrap();
         *slot = 23;
         assert_eq!(

src/commands/char_grid.rs

@@ -1,7 +1,7 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code,
-    commands::TryFromPacketError, CharGrid, Header, Origin, Packet, Tiles,
-    TypedCommand,
+    commands::errors::TryFromPacketError, CharGrid, Header, Origin, Packet,
+    Tiles, TryIntoPacketError, TypedCommand,
 };
 
 /// Show text on the screen.
@@ -16,21 +16,23 @@ use crate::{
 /// let grid = CharGrid::from("Hello,\nWorld!");
 /// connection.send(CharGridCommand { origin: Origin::ZERO, grid }).expect("send failed");
 /// ```
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct CharGridCommand {
-    /// which tile the text should start
-    pub origin: Origin<Tiles>,
     /// the text to send to the display
     pub grid: CharGrid,
+    /// which tile the text should start on
+    pub origin: Origin<Tiles>,
 }
 
-impl From<CharGridCommand> for Packet {
-    fn from(value: CharGridCommand) -> Self {
-        Packet::origin_grid_to_packet(
+impl TryFrom<CharGridCommand> for Packet {
+    type Error = TryIntoPacketError;
+
+    fn try_from(value: CharGridCommand) -> Result<Self, Self::Error> {
+        Ok(Packet::origin_grid_to_packet(
             value.origin,
             value.grid,
             CommandCode::Utf8Data,
-        )
+        )?)
     }
 }
 
@@ -82,9 +84,11 @@ impl From<CharGridCommand> for TypedCommand {
 
 #[cfg(test)]
 mod tests {
-    use crate::commands::tests::round_trip;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
     use crate::{CharGrid, CharGridCommand, Origin};
 
+    impl TestImplementsCommand for CharGridCommand {}
+
     #[test]
     fn round_trip_utf8_data() {
         round_trip(

src/commands/clear.rs

@@ -1,6 +1,6 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code_only,
-    commands::TryFromPacketError, Packet, TypedCommand,
+    commands::errors::TryFromPacketError, Packet, TypedCommand,
 };
 use std::fmt::Debug;
 
@@ -12,7 +12,7 @@ use std::fmt::Debug;
 /// # use servicepoint::*;
 /// # let connection = FakeConnection;
 /// connection.send(ClearCommand).unwrap();
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 /// ```
 pub struct ClearCommand;
 
@@ -43,8 +43,11 @@ impl From<ClearCommand> for TypedCommand {
 #[cfg(test)]
 mod tests {
     use super::*;
+    use crate::commands::tests::TestImplementsCommand;
     use crate::Header;
 
+    impl TestImplementsCommand for ClearCommand {}
+
     #[test]
     fn round_trip() {
         crate::commands::tests::round_trip(ClearCommand.into());

src/commands/cp437_grid.rs

@@ -1,7 +1,7 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code,
-    commands::TryFromPacketError, Cp437Grid, Header, Origin, Packet, Tiles,
-    TypedCommand,
+    commands::errors::TryFromPacketError, Cp437Grid, Header, Origin, Packet,
+    Tiles, TryIntoPacketError, TypedCommand,
 };
 
 /// Show text on the screen.
@@ -27,21 +27,23 @@ use crate::{
 /// connection.send(Cp437GridCommand{ origin: Origin::new(2, 2), grid }).unwrap();
 /// ```
 /// [CP-437]: https://en.wikipedia.org/wiki/Code_page_437
-#[derive(Clone, Debug, PartialEq)]
+#[derive(Clone, Debug, PartialEq, Eq)]
 pub struct Cp437GridCommand {
-    /// which tile the text should start
-    pub origin: Origin<Tiles>,
     /// the text to send to the display
     pub grid: Cp437Grid,
+    /// which tile the text should start
+    pub origin: Origin<Tiles>,
 }
 
-impl From<Cp437GridCommand> for Packet {
-    fn from(value: Cp437GridCommand) -> Self {
-        Packet::origin_grid_to_packet(
+impl TryFrom<Cp437GridCommand> for Packet {
+    type Error = TryIntoPacketError;
+
+    fn try_from(value: Cp437GridCommand) -> Result<Self, Self::Error> {
+        Ok(Packet::origin_grid_to_packet(
             value.origin,
             value.grid,
             CommandCode::Cp437Data,
-        )
+        )?)
     }
 }
 
@@ -91,7 +93,9 @@ impl From<Cp437GridCommand> for TypedCommand {
 #[cfg(test)]
 mod tests {
     use super::*;
-    use crate::commands::tests::round_trip;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
+
+    impl TestImplementsCommand for Cp437GridCommand {}
 
     #[test]
     fn round_trip_cp437_data() {

src/commands/errors.rs

@@ -0,0 +1,44 @@
+use crate::LoadBitmapError;
+use std::num::TryFromIntError;
+
+/// Err values for [crate::TypedCommand::try_from].
+#[derive(Debug, PartialEq, thiserror::Error)]
+pub enum TryFromPacketError {
+    /// the contained command code does not correspond to a known command
+    #[error("The command code {0:?} does not correspond to a known command")]
+    InvalidCommand(u16),
+    /// the expected payload size was n, but size m was found
+    #[error("the expected payload size was {0}, but size {1} was found")]
+    UnexpectedPayloadSize(usize, usize),
+    /// Header fields not needed for the command have been used.
+    ///
+    /// Note that these commands would usually still work on the actual display.
+    #[error("Header fields not needed for the command have been used")]
+    ExtraneousHeaderValues,
+    /// The contained compression code is not known. This could be of disabled features.
+    #[error("The compression code {0:?} does not correspond to a known compression algorithm.")]
+    InvalidCompressionCode(u16),
+    /// Decompression of the payload failed. This can be caused by corrupted packets.
+    #[error("The decompression of the payload failed")]
+    DecompressionFailed,
+    /// The given brightness value is out of bounds
+    #[error("The given brightness value {0} is out of bounds.")]
+    InvalidBrightness(u8),
+    /// Some provided text was not valid UTF-8.
+    #[error(transparent)]
+    InvalidUtf8(#[from] std::string::FromUtf8Error),
+    /// The bitmap contained in the payload could not be loaded
+    #[error(transparent)]
+    LoadBitmapFailed(#[from] LoadBitmapError),
+}
+
+/// An error that can occur when parsing a raw packet as a command
+#[derive(Debug, PartialEq, thiserror::Error)]
+pub enum TryIntoPacketError {
+    /// Compression of the payload failed.
+    #[error("The compression of the payload failed")]
+    CompressionFailed,
+    /// Conversion (probably to u16) failed
+    #[error(transparent)]
+    ConversionError(#[from] TryFromIntError),
+}

src/commands/fade_out.rs

@@ -1,6 +1,6 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code_only,
-    commands::TryFromPacketError, Packet, TypedCommand,
+    commands::errors::TryFromPacketError, Packet, TypedCommand,
 };
 use std::fmt::Debug;
 
@@ -15,7 +15,7 @@ use std::fmt::Debug;
 /// # let connection = FakeConnection;
 /// connection.send(FadeOutCommand).unwrap();
 /// ```
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct FadeOutCommand;
 
 impl TryFrom<Packet> for FadeOutCommand {
@@ -45,10 +45,11 @@ impl From<FadeOutCommand> for TypedCommand {
 #[cfg(test)]
 mod tests {
     use crate::command_code::CommandCode;
-    use crate::commands::tests::round_trip;
-    use crate::{
-        FadeOutCommand, Header, Packet, TryFromPacketError, TypedCommand,
-    };
+    use crate::commands::errors::TryFromPacketError;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
+    use crate::{ClearCommand, FadeOutCommand, Header, Packet, TypedCommand};
+
+    impl TestImplementsCommand for FadeOutCommand {}
 
     #[test]
     fn round_trip_fade_out() {

src/commands/hard_reset.rs

@@ -1,6 +1,6 @@
 use crate::{
     command_code::CommandCode, commands::check_command_code_only,
-    commands::TryFromPacketError, Packet, TypedCommand,
+    commands::errors::TryFromPacketError, Packet, TypedCommand,
 };
 use std::fmt::Debug;
 
@@ -15,7 +15,7 @@ use std::fmt::Debug;
 /// # let connection = FakeConnection;
 /// connection.send(HardResetCommand).unwrap();
 /// ```
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct HardResetCommand;
 
 impl TryFrom<Packet> for HardResetCommand {
@@ -46,9 +46,11 @@ impl From<HardResetCommand> for TypedCommand {
 #[cfg(test)]
 mod test {
     use super::*;
-    use crate::commands::tests::round_trip;
+    use crate::commands::tests::{round_trip, TestImplementsCommand};
     use crate::Header;
 
+    impl TestImplementsCommand for HardResetCommand {}
+
     #[test]
     fn round_trip_hard_reset() {
         round_trip(HardResetCommand.into());

src/commands/mod.rs

@@ -6,6 +6,7 @@ mod brightness_grid;
 mod char_grid;
 mod clear;
 mod cp437_grid;
+mod errors;
 mod fade_out;
 mod hard_reset;
 mod typed;
@@ -22,6 +23,7 @@ pub use brightness_grid::*;
 pub use char_grid::*;
 pub use clear::*;
 pub use cp437_grid::*;
+pub use errors::*;
 pub use fade_out::*;
 pub use hard_reset::*;
 pub use typed::*;
@@ -74,9 +76,12 @@ pub use typed::*;
 /// # let connection = FakeConnection;
 /// connection.send(command).unwrap();
 /// ```
-pub trait Command: Debug + Clone + PartialEq + Into<Packet> {}
+pub trait Command:
+    Debug + Clone + Eq + TryInto<Packet> + TryFrom<Packet>
+{
+}
 
-impl<T: Debug + Clone + PartialEq + Into<Packet>> Command for T {}
+impl<T: Debug + Clone + Eq + TryInto<Packet> + TryFrom<Packet>> Command for T {}
 
 fn check_command_code_only(
     packet: Packet,
@@ -121,8 +126,10 @@ fn check_command_code(
 mod tests {
     use crate::*;
 
+    pub(crate) trait TestImplementsCommand: Command {}
+
     pub(crate) fn round_trip(original: TypedCommand) {
-        let packet: Packet = original.clone().into();
+        let packet: Packet = original.clone().try_into().unwrap();
         let copy: TypedCommand = match TypedCommand::try_from(packet) {
             Ok(command) => command,
             Err(err) => panic!("could not reload {original:?}: {err:?}"),

src/commands/typed.rs

@@ -1,70 +1,31 @@
 use crate::{
-    command_code::CommandCode, BitVecCommand, BitmapCommand, BrightnessCommand,
-    BrightnessGridCommand, CharGridCommand, ClearCommand, Cp437GridCommand,
-    FadeOutCommand, HardResetCommand, Header, LoadBitmapError, Packet,
+    command_code::CommandCode, commands::errors::TryFromPacketError,
+    BitVecCommand, BitmapCommand, BrightnessCommand, BrightnessGridCommand,
+    CharGridCommand, ClearCommand, Cp437GridCommand, FadeOutCommand,
+    HardResetCommand, Header, Packet, TryIntoPacketError,
 };
 
 /// This enum contains all commands provided by the library.
 /// This is useful in case you want one data type for all kinds of commands without using `dyn`.
 ///
 /// Please look at the contained structs for documentation per command.
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 #[allow(missing_docs)]
+#[allow(deprecated)]
 pub enum TypedCommand {
     Clear(ClearCommand),
-
     CharGrid(CharGridCommand),
-
     Cp437Grid(Cp437GridCommand),
-
     Bitmap(BitmapCommand),
-
     Brightness(BrightnessCommand),
-
     BrightnessGrid(BrightnessGridCommand),
-
     BitVec(BitVecCommand),
-
     HardReset(HardResetCommand),
-
     FadeOut(FadeOutCommand),
-
-    #[allow(deprecated)]
     #[deprecated]
     BitmapLegacy(crate::BitmapLegacyCommand),
 }
 
-/// Err values for [TypedCommand::try_from].
-#[derive(Debug, PartialEq, thiserror::Error)]
-pub enum TryFromPacketError {
-    /// the contained command code does not correspond to a known command
-    #[error("The command code {0:?} does not correspond to a known command")]
-    InvalidCommand(u16),
-    /// the expected payload size was n, but size m was found
-    #[error("the expected payload size was {0}, but size {1} was found")]
-    UnexpectedPayloadSize(usize, usize),
-    /// Header fields not needed for the command have been used.
-    ///
-    /// Note that these commands would usually still work on the actual display.
-    #[error("Header fields not needed for the command have been used")]
-    ExtraneousHeaderValues,
-    /// The contained compression code is not known. This could be of disabled features.
-    #[error("The compression code {0:?} does not correspond to a known compression algorithm.")]
-    InvalidCompressionCode(u16),
-    /// Decompression of the payload failed. This can be caused by corrupted packets.
-    #[error("The decompression of the payload failed")]
-    DecompressionFailed,
-    /// The given brightness value is out of bounds
-    #[error("The given brightness value {0} is out of bounds.")]
-    InvalidBrightness(u8),
-    /// Some provided text was not valid UTF-8.
-    #[error(transparent)]
-    InvalidUtf8(#[from] std::string::FromUtf8Error),
-    /// The bitmap contained in the payload could not be loaded
-    #[error(transparent)]
-    LoadBitmapFailed(#[from] LoadBitmapError),
-}
-
 impl TryFrom<Packet> for TypedCommand {
     type Error = TryFromPacketError;
 
@@ -136,27 +97,33 @@ impl TryFrom<Packet> for TypedCommand {
     }
 }
 
-impl From<TypedCommand> for Packet {
-    fn from(command: TypedCommand) -> Self {
-        match command {
+impl TryFrom<TypedCommand> for Packet {
+    type Error = TryIntoPacketError;
+
+    fn try_from(value: TypedCommand) -> Result<Self, Self::Error> {
+        Ok(match value {
             TypedCommand::Clear(c) => c.into(),
-            TypedCommand::CharGrid(c) => c.into(),
-            TypedCommand::Cp437Grid(c) => c.into(),
-            TypedCommand::Bitmap(c) => c.into(),
+            TypedCommand::CharGrid(c) => c.try_into()?,
+            TypedCommand::Cp437Grid(c) => c.try_into()?,
+            TypedCommand::Bitmap(c) => c.try_into()?,
             TypedCommand::Brightness(c) => c.into(),
-            TypedCommand::BrightnessGrid(c) => c.into(),
-            TypedCommand::BitVec(c) => c.into(),
+            TypedCommand::BrightnessGrid(c) => c.try_into()?,
+            TypedCommand::BitVec(c) => c.try_into()?,
             TypedCommand::HardReset(c) => c.into(),
             TypedCommand::FadeOut(c) => c.into(),
             #[allow(deprecated)]
             TypedCommand::BitmapLegacy(c) => c.into(),
-        }
+        })
     }
 }
 
 #[cfg(test)]
 mod tests {
-    use crate::{Header, Packet, TryFromPacketError, TypedCommand};
+    use crate::commands::errors::TryFromPacketError;
+    use crate::commands::tests::TestImplementsCommand;
+    use crate::{Header, Packet, TypedCommand};
+
+    impl TestImplementsCommand for TypedCommand {}
 
     #[test]
     fn error_invalid_command() {

src/compression.rs

@@ -5,6 +5,7 @@ use std::io::{Read, Write};
 use bzip2::read::{BzDecoder, BzEncoder};
 #[cfg(feature = "compression_zlib")]
 use flate2::{FlushCompress, FlushDecompress, Status};
+use log::error;
 #[cfg(feature = "compression_zstd")]
 use zstd::{Decoder as ZstdDecoder, Encoder as ZstdEncoder};
 
@@ -67,28 +68,39 @@ pub(crate) fn into_decompressed(
     }
 }
 
-#[allow(clippy::unwrap_used)]
 pub(crate) fn into_compressed(
     kind: CompressionCode,
     payload: Payload,
-) -> Payload {
+) -> Option<Payload> {
     match kind {
-        CompressionCode::Uncompressed => payload,
+        CompressionCode::Uncompressed => Some(payload),
         #[cfg(feature = "compression_zlib")]
         CompressionCode::Zlib => {
             let mut compress =
                 flate2::Compress::new(flate2::Compression::fast(), true);
             let mut buffer = [0u8; 10000];
 
-            match compress
-                .compress(&payload, &mut buffer, FlushCompress::Finish)
-                .expect("compress failed")
-            {
-                Status::Ok => panic!("buffer should be big enough"),
-                Status::BufError => panic!("BufError"),
-                Status::StreamEnd => {}
-            };
-            buffer[..compress.total_out() as usize].to_owned()
+            match compress.compress(
+                &payload,
+                &mut buffer,
+                FlushCompress::Finish,
+            ) {
+                Ok(Status::Ok) => {
+                    error!("buffer not big enough");
+                    None
+                }
+                Ok(Status::BufError) => {
+                    error!("Could not compress: {:?}", Status::BufError);
+                    None
+                }
+                Ok(Status::StreamEnd) => {
+                    Some(buffer[..compress.total_out() as usize].to_owned())
+                }
+                Err(_) => {
+                    error!("compress returned err");
+                    None
+                }
+            }
         }
         #[cfg(feature = "compression_bzip2")]
         CompressionCode::Bzip2 => {
@@ -96,21 +108,39 @@ pub(crate) fn into_compressed(
                 BzEncoder::new(&*payload, bzip2::Compression::fast());
             let mut compressed = vec![];
             match encoder.read_to_end(&mut compressed) {
-                Err(err) => panic!("could not compress payload: {}", err),
-                Ok(_) => compressed,
+                Err(err) => {
+                    error!("Could not compress: {:?}", err);
+                    None
+                }
+                Ok(_) => Some(compressed),
             }
         }
         #[cfg(feature = "compression_lzma")]
-        CompressionCode::Lzma => lzma::compress(&payload, 6).unwrap(),
+        CompressionCode::Lzma => match lzma::compress(&payload, 6) {
+            Ok(payload) => Some(payload),
+            Err(e) => {
+                error!("Could not compress: {e:?}");
+                None
+            }
+        },
         #[cfg(feature = "compression_zstd")]
         CompressionCode::Zstd => {
+            let buf = Vec::with_capacity(payload.len());
             let mut encoder =
-                ZstdEncoder::new(vec![], zstd::DEFAULT_COMPRESSION_LEVEL)
-                    .expect("could not create encoder");
-            encoder
-                .write_all(&payload)
-                .expect("could not compress payload");
-            encoder.finish().expect("could not finish encoding")
+                match ZstdEncoder::new(buf, zstd::DEFAULT_COMPRESSION_LEVEL) {
+                    Err(e) => {
+                        error!("failed to create decoder: {e:?}");
+                        return None;
+                    }
+                    Ok(encoder) => encoder,
+                };
+
+            if let Err(e) = encoder.write_all(&payload) {
+                error!("failed to decompress payload: {e:?}");
+                return None;
+            }
+
+            encoder.finish().ok()
         }
     }
 }

src/compression_code.rs

@@ -21,7 +21,7 @@
 /// };
 /// ```
 #[repr(u16)]
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum CompressionCode {
     /// no compression
     Uncompressed = 0x0,

src/connections/fake.rs

@@ -1,16 +1,28 @@
-use crate::{Connection, Packet};
+use crate::{Connection, Packet, SendError};
 use log::debug;
+use std::{convert::Infallible, error::Error, fmt::Debug};
 
 #[derive(Debug)]
 /// A fake connection for testing that does not actually send anything.
 pub struct FakeConnection;
 
 impl Connection for FakeConnection {
-    // TODO: () does not implement Error+Debug, some placeholder is needed
-    type Error = std::io::Error;
+    type TransportError = Infallible;
 
-    fn send(&self, packet: impl Into<Packet>) -> Result<(), Self::Error> {
-        let data: Vec<u8> = packet.into().into();
+    fn send<P: TryInto<Packet>>(
+        &self,
+        packet: P,
+    ) -> Result<
+        (),
+        SendError<<P as TryInto<Packet>>::Error, Self::TransportError>,
+    >
+    where
+        <P as TryInto<Packet>>::Error: Error + Debug,
+    {
+        let data: Vec<u8> = packet
+            .try_into()
+            .map(Into::<Vec<u8>>::into)
+            .map_err(SendError::IntoPacket)?;
         debug!("Sending fake packet: {data:?}");
         Ok(())
     }

src/connections/mod.rs

@@ -1,8 +1,7 @@
 //! This module contains the [Connection] trait and all implementations provided in this library.
 
 use crate::Packet;
-use std::error::Error;
-use std::fmt::Debug;
+use std::{error::Error, fmt::Debug};
 
 mod fake;
 #[cfg(feature = "protocol_udp")]
@@ -16,6 +15,20 @@ pub use udp::*;
 #[cfg(feature = "protocol_websocket")]
 pub use websocket::*;
 
+/// An error that can happen when sending a command
+#[derive(Debug, thiserror::Error)]
+pub enum SendError<
+    IntoPacketError: Error + Debug,
+    TransportError: Error + Debug,
+> {
+    /// An error occurred while sending the bytes via the underlying transport
+    #[error("An error occurred while sending the bytes via the underlying transport: {0:?}")]
+    Transport(TransportError),
+    /// An error occurred while preparing the data to send
+    #[error("An error occurred while preparing the data to send: {0:?}")]
+    IntoPacket(IntoPacketError),
+}
+
 /// A connection to the display.
 ///
 /// Used to send [Packets][Packet] or [Commands][crate::Command].
@@ -30,7 +43,7 @@ pub use websocket::*;
 /// ```
 pub trait Connection: Debug {
     /// The error that can occur when sending a packet
-    type Error: Error + Debug;
+    type TransportError: Error + Debug;
 
     /// Send something packet-like to the display. Usually this is in the form of a Command.
     ///
@@ -49,5 +62,13 @@ pub trait Connection: Debug {
     ///  connection.send(servicepoint::ClearCommand)
     ///      .expect("send failed");
     /// ```
-    fn send(&self, packet: impl Into<Packet>) -> Result<(), Self::Error>;
+    fn send<P: TryInto<Packet>>(
+        &self,
+        packet: P,
+    ) -> Result<
+        (),
+        SendError<<P as TryInto<Packet>>::Error, Self::TransportError>,
+    >
+    where
+        <P as TryInto<Packet>>::Error: Error + Debug;
 }

src/connections/udp.rs

@@ -1,6 +1,5 @@
-use crate::{Connection, Packet};
-use std::fmt::Debug;
-use std::net::UdpSocket;
+use crate::{Connection, Packet, SendError};
+use std::{error::Error, fmt::Debug, net::UdpSocket};
 
 /// A connection using the UDP protocol.
 ///
@@ -39,11 +38,26 @@ impl UdpConnection {
 }
 
 impl Connection for UdpConnection {
-    type Error = std::io::Error;
+    type TransportError = std::io::Error;
 
-    fn send(&self, packet: impl Into<Packet>) -> Result<(), Self::Error> {
-        let data: Vec<u8> = packet.into().into();
-        self.socket.send(&data).map(move |_| ()) // ignore Ok value
+    fn send<P: TryInto<Packet>>(
+        &self,
+        packet: P,
+    ) -> Result<
+        (),
+        SendError<<P as TryInto<Packet>>::Error, Self::TransportError>,
+    >
+    where
+        <P as TryInto<Packet>>::Error: Error + Debug,
+    {
+        let data: Vec<u8> = packet
+            .try_into()
+            .map(Into::<Vec<u8>>::into)
+            .map_err(SendError::IntoPacket)?;
+        self.socket
+            .send(&data)
+            .map(move |_| ())
+            .map_err(SendError::Transport) // ignore Ok value
     }
 }
 

src/connections/websocket.rs

@@ -1,4 +1,5 @@
-use crate::{Connection, Packet};
+use crate::{Connection, Packet, SendError};
+use std::{error::Error, fmt::Debug};
 
 /// A connection using the WebSocket protocol.
 ///
@@ -20,12 +21,27 @@ pub struct WebsocketConnection(
 );
 
 impl Connection for WebsocketConnection {
-    type Error = tungstenite::Error;
+    type TransportError = tungstenite::Error;
 
-    fn send(&self, packet: impl Into<Packet>) -> Result<(), Self::Error> {
-        let data: Vec<u8> = packet.into().into();
+    fn send<P: TryInto<Packet>>(
+        &self,
+        packet: P,
+    ) -> Result<
+        (),
+        SendError<<P as TryInto<Packet>>::Error, Self::TransportError>,
+    >
+    where
+        <P as TryInto<Packet>>::Error: Error + Debug,
+    {
+        let data: Vec<u8> = packet
+            .try_into()
+            .map(Into::<Vec<u8>>::into)
+            .map_err(SendError::IntoPacket)?
+            .into();
         let mut socket = self.0.lock().unwrap();
-        socket.send(tungstenite::Message::Binary(data.into()))
+        socket
+            .send(tungstenite::Message::Binary(data.into()))
+            .map_err(SendError::Transport)
     }
 }
 
@@ -63,6 +79,6 @@ impl WebsocketConnection {
 
 impl Drop for WebsocketConnection {
     fn drop(&mut self) {
-        _ = self.0.try_lock().map(move |mut sock| sock.close(None));
+        drop(self.0.try_lock().map(move |mut sock| sock.close(None)));
     }
 }

src/containers/bitmap.rs

@@ -153,6 +153,7 @@ impl Bitmap {
     ///     pixel.set(index % 2 == 0)
     /// }
     /// ```
+    #[must_use]
     pub fn iter_mut(&mut self) -> IterMut<u8, Msb0> {
         self.bit_vec.iter_mut()
     }
@@ -258,6 +259,7 @@ impl From<&Bitmap> for ValueGrid<bool> {
     }
 }
 
+#[must_use]
 struct IterRows<'t> {
     bitmap: &'t Bitmap,
     row: usize,

src/containers/char_grid.rs

@@ -33,6 +33,7 @@ impl CharGrid {
     /// # use servicepoint::CharGrid;
     /// let grid = CharGrid::wrap_str(2, "abc\ndef");
     /// ```
+    #[must_use]
     pub fn wrap_str(width: usize, text: &str) -> Self {
         let lines = text
             .split('\n')

src/containers/value_grid.rs

@@ -13,7 +13,7 @@ impl<T: Sized + Default + Copy + Clone + Debug> Value for T {}
 ///
 /// This structure can be used with any type that implements the [Value] trait.
 /// You can also use the concrete type aliases provided in this crate, e.g. [CharGrid] and [ByteGrid].
-#[derive(Debug, Clone, PartialEq)]
+#[derive(Debug, Clone, PartialEq, Eq)]
 pub struct ValueGrid<T: Value> {
     width: usize,
     height: usize,
@@ -50,6 +50,7 @@ impl<T: Value> ValueGrid<T> {
     /// - height: size in y-direction
     ///
     /// returns: [ValueGrid] initialized to default value.
+    #[must_use]
     pub fn new(width: usize, height: usize) -> Self {
         Self {
             data: vec![Default::default(); width * height],
@@ -193,6 +194,7 @@ impl<T: Value> ValueGrid<T> {
     /// ```
     /// [Brightness]: [crate::Brightness]
     /// [Command]: [crate::Command]
+    #[must_use]
     pub fn map<TConverted, F>(&self, f: F) -> ValueGrid<TConverted>
     where
         TConverted: Value,
@@ -358,11 +360,13 @@ impl<T: Value> Grid<T> for ValueGrid<T> {
 
 impl<T: Value> DataRef<T> for ValueGrid<T> {
     /// Get the underlying byte rows mutable
+    #[must_use]
     fn data_ref_mut(&mut self) -> &mut [T] {
         self.data.as_mut_slice()
     }
 
     /// Get the underlying byte rows read only
+    #[must_use]
     fn data_ref(&self) -> &[T] {
         self.data.as_slice()
     }
@@ -376,6 +380,7 @@ impl<T: Value> From<ValueGrid<T>> for Vec<T> {
 }
 
 /// An iterator iver the rows in a [ValueGrid]
+#[must_use]
 pub struct IterGridRows<'t, T: Value> {
     grid: &'t ValueGrid<T>,
     row: usize,

src/origin.rs

@@ -2,7 +2,7 @@ use crate::TILE_SIZE;
 use std::marker::PhantomData;
 
 /// An origin marks the top left position of a window sent to the display.
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct Origin<Unit: DisplayUnit> {
     /// position in the width direction
     pub x: usize,
@@ -44,11 +44,11 @@ impl<T: DisplayUnit> std::ops::Add<Origin<T>> for Origin<T> {
 pub trait DisplayUnit {}
 
 /// Marks something to be measured in number of pixels.
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct Pixels();
 
 /// Marks something to be measured in number of iles.
-#[derive(Debug, Copy, Clone, PartialEq)]
+#[derive(Debug, Copy, Clone, PartialEq, Eq)]
 pub struct Tiles();
 
 impl DisplayUnit for Pixels {}
@@ -86,6 +86,12 @@ impl TryFrom<&Origin<Pixels>> for Origin<Tiles> {
     }
 }
 
+impl<Unit: DisplayUnit> Default for Origin<Unit> {
+    fn default() -> Self {
+        Self::ZERO
+    }
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;

src/packet.rs

@@ -23,9 +23,8 @@
 //! let packet = Packet::try_from(bytes).expect("could not read packet from bytes");
 //! ```
 
-use crate::command_code::CommandCode;
-use crate::{Grid, Origin, Tiles};
-use std::mem::size_of;
+use crate::{command_code::CommandCode, Grid, Origin, Tiles};
+use std::{mem::size_of, num::TryFromIntError};
 
 /// A raw header.
 ///
@@ -144,17 +143,17 @@ impl Packet {
         origin: Origin<Tiles>,
         grid: impl Grid<T> + Into<Payload>,
         command_code: CommandCode,
-    ) -> Packet {
-        Packet {
+    ) -> Result<Packet, TryFromIntError> {
+        Ok(Packet {
             header: Header {
                 command_code: command_code.into(),
-                a: origin.x as u16,
-                b: origin.y as u16,
-                c: grid.width() as u16,
-                d: grid.height() as u16,
+                a: origin.x.try_into()?,
+                b: origin.y.try_into()?,
+                c: grid.width().try_into()?,
+                d: grid.height().try_into()?,
             },
             payload: grid.into(),
-        }
+        })
     }
 
     pub(crate) fn command_code_only(c: CommandCode) -> Self {