Asset: Add helper to get specific process flow

Author: alexdewar

src/asset.rs

@@ -5,6 +5,7 @@ use crate::process::{Process, ProcessFlow, ProcessParameter};
 use crate::region::RegionID;
 use crate::time_slice::TimeSliceID;
 use anyhow::{ensure, Context, Result};
+use indexmap::IndexMap;
 use std::collections::HashSet;
 use std::ops::RangeInclusive;
 use std::rc::Rc;
@@ -108,13 +109,22 @@ impl Asset {
         self.capacity * self.process_parameter.capacity_to_activity
     }
 
-    /// Iterate over the asset's flows
-    pub fn iter_flows(&self) -> impl Iterator<Item = &ProcessFlow> {
+    /// Get a specific process flow
+    pub fn get_flow(&self, commodity_id: &CommodityID) -> Option<&ProcessFlow> {
+        self.get_flows_map().get(commodity_id)
+    }
+
+    /// Get the process flows map for this asset
+    fn get_flows_map(&self) -> &IndexMap<CommodityID, ProcessFlow> {
         self.process
             .flows
             .get(&(self.region_id.clone(), self.commission_year))
             .unwrap()
-            .values()
+    }
+
+    /// Iterate over the asset's flows
+    pub fn iter_flows(&self) -> impl Iterator<Item = &ProcessFlow> {
+        self.get_flows_map().values()
     }
 
     /// Iterate over the asset's Primary Activity Commodity flows