(rust) temperature type and conversions

rust/src/main.rs

@@ -1,38 +1,115 @@
 #![allow(dead_code, unused)]
 
-use std::net::{IpAddr, SocketAddr, TcpStream};
-
-use clap::Parser;
 use serde::{Deserialize, Serialize};
-use serde_json::Value;
-use tokio::{fs, io::AsyncWriteExt, net::TcpListener, sync::mpsc};
-
-#[derive(Clone, Debug, Parser)]
-pub struct Args {
-    #[arg(long, default_value_t = false)]
-    pub host: bool,
-
-    #[arg(short, long)]
-    pub address: SocketAddr,
-}
 
 #[tokio::main]
 async fn main() -> anyhow::Result<()> {
-    let args: Args = Parser::parse();
+    for n in 0..16 {
+        let measurement: u16 = 65_535 / 16 * n;
+        let millikelvin = (((measurement as u32) * 21_875u32) >> 13) + 228_150u32;
+        let temperature = Temperature::from_millikelvin(millikelvin);
 
-    if args.host {
+        println!("raw = {measurement}, converted = {millikelvin}, temperature = {temperature}");
-        let listener: TcpListener = TcpListener::bind(args.address).await?;
-
-        loop {
-            if let Ok((mut stream, _)) = listener.accept().await {
-                println!("local address = {}, peer address = {}", stream.local_addr()?, stream.peer_addr()?);
-                stream.shutdown();
-            }
-        }
-    } else {
-        let mut stream: TcpStream = TcpStream::connect(args.address)?;
     }
+    let measurement: u16 = 65_535;
+    let millikelvin = (((measurement as u32) * 21_875u32) >> 13) + 228_150u32;
+    let temperature = Temperature::from_millikelvin(millikelvin);
+
+    println!("raw = {measurement}, converted = {millikelvin}, temperature = {temperature}");
 
     Ok(())
 }
 
+#[derive(Clone, Debug, thiserror::Error)]
+pub enum TemperatureError {
+    #[error("provided input is invalid: {0}")]
+    InvalidInput(f32),
+    #[error("conversion between units changed the value noticeably")]
+    ConversionError,
+}
+
+/// type for temperature
+/// represents the temperature in Millikelvin
+#[derive(Clone, Copy, Debug, Deserialize, Serialize)]
+pub struct Temperature{
+    value: u32,
+}
+
+impl Temperature {
+    #[allow(non_upper_case_globals)]
+    const CELSIUS_OFFSET_C: f32 = 273.15f32;
+
+    /// create a new instance of `Temperature` from a value in Millikelvin
+    /// this function is an alias for `from_millikelvin()`
+    pub fn new(millikelvin: u32) -> Self {
+        Self::from_millikelvin(millikelvin)
+    }
+
+    /// create a new instance of `Temperature` from a value in Millikelvin
+    pub fn from_millikelvin(millikelvin: u32) -> Self {
+        Self { value: millikelvin }
+    }
+
+    /// create a new instance of `Temperature` from a value in degrees Celsius
+    pub fn from_celsius(celsius: f32) -> Result<Self, TemperatureError> {
+        if celsius < -Self::CELSIUS_OFFSET_C { return Err(TemperatureError::InvalidInput(celsius)) }
+        Ok(Self { value: Self::celsius_to_millikelvin(celsius)? })
+    }
+
+    /// returns the temperature value in Millikelvin
+    pub fn get_millikelvin(&self) -> u32 {
+        self.value
+    }
+
+    /// returns the temperature value in degrees celsius
+    pub fn get_celsius(&self) -> Result<f32, TemperatureError> {
+        Self::millikelvin_to_celsius(self.value)
+    }
+
+    fn celsius_to_millikelvin(celsius: f32) -> Result<u32, TemperatureError> {
+        const ACCEPTABLE_INACCURACY: f32 = 1.0 / 16.0;
+
+        let millikelvin: u32 = Self::celsius_to_millikelvin_unchecked(celsius);
+        let celsius_converted: f32 = Self::millikelvin_to_celsius_unchecked(millikelvin);
+
+        if f32::abs(celsius - celsius_converted) > ACCEPTABLE_INACCURACY {
+            return Err(TemperatureError::ConversionError);
+        }
+
+        Ok(millikelvin)
+    }
+
+    fn millikelvin_to_celsius(millikelvin: u32) -> Result<f32, TemperatureError> {
+        const ACCEPTABLE_INACCURACY: u32 = 80;
+
+        let celsius: f32 = Self::millikelvin_to_celsius_unchecked(millikelvin);
+        let millikelvin_converted: u32 = Self::celsius_to_millikelvin_unchecked(celsius);
+
+        if millikelvin.wrapping_sub(millikelvin_converted) > ACCEPTABLE_INACCURACY {
+            return Err(TemperatureError::ConversionError);
+        }
+
+        Ok(celsius)
+    }
+
+    fn celsius_to_millikelvin_unchecked(celsius: f32) -> u32 {
+        ((celsius + Self::CELSIUS_OFFSET_C) * 1000.0) as u32
+    }
+
+    fn millikelvin_to_celsius_unchecked(millikelvin: u32) -> f32 {
+        let millicelsius: f32 = (millikelvin as f32) / 1000.0;
+        millicelsius - Self::CELSIUS_OFFSET_C
+    }
+}
+
+impl std::fmt::Display for Temperature {
+    // display `Temperatures` in degrees Celsius
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        if let Ok(value) = Self::millikelvin_to_celsius(self.value) {
+            write!(f, "{:.2?}°C", value)?;
+        } else {
+            return Err(std::fmt::Error::default());
+        }
+        Ok(())
+    }
+}