impl std::default::Default for Quantity, simplifies the code a bunch

tools/src/recipe.rs

@@ -12,22 +12,42 @@ pub enum Unit {
 }
 
 /// `Quantity` measures the amount of a resource (Input or Output).
-#[derive(Clone, Copy, Debug, serde::Deserialize)]
+#[derive(Clone, Copy, serde::Deserialize)]
 pub struct Quantity {
     pub amount: f32,
     pub unit: Option<Unit>,
 }
 
+impl std::default::Default for Quantity {
+    fn default() -> Self {
+        Self {
+            amount: 1.0,
+            unit: None,
+        }
+    }
+}
+
+impl std::fmt::Debug for Quantity {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match &self.unit {
+            None => write!(f, "{:#}", self.amount),
+            Some(unit) => write!(f, "{:#} {:?}", self.amount, unit),
+        }
+    }
+}
+
 #[derive(Debug, serde::Deserialize)]
 pub struct Input {
     // Quantity defaults to "amount=1" if omitted.
-    pub quantity: Option<Quantity>,
+    #[serde(default)]
+    pub quantity: Quantity,
 }
 
 #[derive(Debug, serde::Deserialize)]
 pub struct Output {
     // Quantity defaults to "amount=1" if omitted.
-    pub quantity: Option<Quantity>,
+    #[serde(default)]
+    pub quantity: Quantity,
 }
 
 #[derive(Debug, serde::Deserialize)]
@@ -73,30 +93,6 @@ pub struct Recipe {
     pub outputs: Option<std::collections::HashMap<String, Output>>,
 }
 
-impl Input {
-    pub fn get_quantity(&self) -> Quantity {
-        match &self.quantity {
-            None => Quantity {
-                amount: 1.0,
-                unit: None,
-            },
-            Some(q) => q.clone(),
-        }
-    }
-}
-
-impl Output {
-    pub fn get_quantity(&self) -> Quantity {
-        match &self.quantity {
-            None => Quantity {
-                amount: 1.0,
-                unit: None,
-            },
-            Some(q) => q.clone(),
-        }
-    }
-}
-
 impl Recipe {
     pub fn from_file(file: &std::path::PathBuf) -> anyhow::Result<Self> {
         let recipe_contents = std::fs::read_to_string(file)?;

tools/src/repo.rs

@@ -93,9 +93,7 @@ impl Repo {
             if input_name == "capital" {
                 // The build process begins in capitalism :-(
 
-                let input_quantity = input_info.get_quantity();
+                let input_unit = match &input_info.quantity.unit {
-
-                let input_unit = match &input_quantity.unit {
                     None => {
                         return Err(anyhow::Error::msg(format!(
                             "expected quantity unit USDollar on capital input"
@@ -109,7 +107,7 @@ impl Repo {
                     Some(unit) => unit,
                 };
 
-                let cost = input_quantity.amount;
+                let cost = input_info.quantity.amount;
 
                 let outputs = match &recipe.outputs {
                     None => return Err(anyhow::Error::msg(format!("no outputs!"))),
@@ -118,9 +116,8 @@ impl Repo {
 
                 if outputs.len() == 1 {
                     for (_output_name, output_info) in outputs.iter() {
-                        let output_quantity = output_info.get_quantity();
+                        let cost_each = cost / output_info.quantity.amount;
-                        let cost_each = cost / output_quantity.amount;
+                        if let Some(output_unit) = output_info.quantity.unit {
-                        if let Some(output_unit) = output_quantity.unit {
                             println!(
                                 "capital: {:.3} {:?} / {:?}  :-(",
                                 cost_each, input_unit, output_unit
@@ -134,7 +131,7 @@ impl Repo {
                 }
                 continue;
             }
-            println!("{input_name:?} {input_info:?}");
+            println!("{input_name:?} ({:?})", input_info.quantity);
             match self.get_recipe(input_name) {
                 None => {
                     return Err(anyhow::Error::msg(format!(