Added Amount mod

Author: deadblackclover

examples/get_balance.rs

@@ -1,4 +1,5 @@
 use wavesplatform::node::{Node, MAINNET_URL};
+use wavesplatform::util::Amount;
 
 #[tokio::main]
 async fn main() -> Result<(), Box<dyn std::error::Error>> {
@@ -9,13 +10,17 @@ async fn main() -> Result<(), Box<dyn std::error::Error>> {
         .get_balance("3PEktVux2RhchSN63DsDo4b4mz4QqzKSeDv")
         .await?;
 
-    println!("Balance: {} WAVES", result.balance());
+    let balance = Amount::from_wavelet(result.balance());
+
+    println!("Balance: {} WAVES", balance);
 
     let result = node
         .get_balance_details("3PEktVux2RhchSN63DsDo4b4mz4QqzKSeDv")
         .await?;
 
-    println!("Regular balance: {} WAVES", result.regular());
+    let balance = Amount::from_wavelet(result.regular());
+
+    println!("Regular balance: {} WAVES", balance);
 
     Ok(())
 }

src/node.rs

@@ -34,6 +34,7 @@ impl<'a> Node<'a> {
     /// Get the regular balance in WAVES at a given address
     /// ```no_run
     /// use wavesplatform::node::{Node, MAINNET_URL};
+    /// use wavesplatform::util::Amount;
     ///
     /// #[tokio::main]
     /// async fn main() -> Result<(), Box<dyn std::error::Error>> {
@@ -43,7 +44,9 @@ impl<'a> Node<'a> {
     ///         .get_balance("3PEktVux2RhchSN63DsDo4b4mz4QqzKSeDv")
     ///         .await?;
     ///
-    ///     println!("Balance: {} WAVES", result.balance());
+    ///     let balance = Amount::from_wavelet(result.balance());
+    ///
+    ///     println!("Balance: {} WAVES", balance);
     ///
     ///     Ok(())
     /// }
@@ -62,6 +65,7 @@ impl<'a> Node<'a> {
     /// Get the available, regular, generating, and effective balance
     /// ```no_run
     /// use wavesplatform::node::{Node, MAINNET_URL};
+    /// use wavesplatform::util::Amount;
     ///
     /// #[tokio::main]
     /// async fn main() -> Result<(), Box<dyn std::error::Error>> {
@@ -71,7 +75,9 @@ impl<'a> Node<'a> {
     ///         .get_balance_details("3PEktVux2RhchSN63DsDo4b4mz4QqzKSeDv")
     ///         .await?;
     ///
-    ///     println!("Regular balance: {} WAVES", result.regular());
+    ///     let balance = Amount::from_wavelet(result.regular());
+    ///
+    ///     println!("Regular balance: {} WAVES", balance);
     ///
     ///     Ok(())
     /// }

src/util.rs

@@ -1,6 +1,10 @@
+mod amount;
+
 use curve25519_dalek::montgomery::MontgomeryPoint;
 use ed25519_dalek::*;
 
+pub use amount::*;
+
 /// Signature verify function
 pub fn sig_verify(
     message: &[u8],

src/util/amount.rs

@@ -0,0 +1,93 @@
+use std::fmt;
+use std::str::FromStr;
+
+/// The number of decimal places (decimals) for WAVES is 8.
+const DECIMALS: usize = 8;
+
+/// The [`Amount`] type can be used to express Waves amounts that supports conversion to various denominations.
+#[derive(Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash)]
+pub struct Amount(u64);
+
+impl Amount {
+    /// The zero amount.
+    pub const ZERO: Amount = Amount(0);
+    /// Exactly one WAVELET.
+    pub const ONE_WAVELET: Amount = Amount(1);
+    /// Exactly one WAVES.
+    pub const ONE_WAVES: Amount = Amount(100_000_000);
+
+    /// Create an [`Amount`] with WAVELET precision and the given number of WAVELET.
+    pub fn from_wavelet(wavelet: u64) -> Amount {
+        Amount(wavelet)
+    }
+
+    /// The maximum value of an [`Amount`].
+    pub fn max_value() -> Amount {
+        Amount(u64::max_value())
+    }
+
+    /// The minimum value of an [`Amount`].
+    pub fn min_value() -> Amount {
+        Amount(u64::min_value())
+    }
+
+    /// Get the number of WAVELET in this [`Amount`].
+    pub fn as_wavelet(self) -> u64 {
+        self.0
+    }
+
+    /// Express this [`Amount`] as a floating-point value in WAVES.
+    pub fn as_waves(self) -> f64 {
+        let real = format!("{:0width$}", self.0, width = DECIMALS);
+
+        if real.len() == DECIMALS {
+            let result = format!("0.{}", &real[real.len() - DECIMALS..]);
+            f64::from_str(&result).unwrap()
+        } else {
+            let result = format!(
+                "{}.{}",
+                &real[0..(real.len() - DECIMALS)],
+                &real[real.len() - DECIMALS..]
+            );
+            f64::from_str(&result).unwrap()
+        }
+    }
+}
+
+impl Default for Amount {
+    fn default() -> Self {
+        Amount::ZERO
+    }
+}
+
+impl fmt::Display for Amount {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        write!(f, "{}", self.as_waves())
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test() {
+        let wavelet = 1_000;
+        let balance = Amount::from_wavelet(wavelet);
+        assert_eq!(balance.as_waves(), 0.00001);
+
+        let wavelet = 1_000_000;
+        let balance = Amount::from_wavelet(wavelet);
+        assert_eq!(balance.as_waves(), 0.01);
+
+        let wavelet = 1_000_000_000;
+        let balance = Amount::from_wavelet(wavelet);
+        assert_eq!(balance.as_waves(), 10.0);
+    }
+
+    #[test]
+    fn test_one_waves() {
+        let one_waves = Amount::ONE_WAVES;
+        assert_eq!(one_waves.as_waves(), 1.0);
+    }
+}