implement traits approach to comparing metrics

Author: Aurashk

src/finance.rs

@@ -30,6 +30,7 @@ pub fn annual_capital_cost(
 
 /// Represents the profitability index of an investment
 /// in terms of it's annualised components.
+#[derive(Debug, Clone, Copy)]
 pub struct ProfitabilityIndex {
     /// the total annualised surplus of an asset
     pub total_annualised_surplus: Money,

src/fixture.rs

@@ -14,6 +14,7 @@ use crate::process::{
     ProcessInvestmentConstraintsMap, ProcessMap, ProcessParameter, ProcessParameterMap,
 };
 use crate::region::RegionID;
+use crate::simulation::investment::appraisal::LCOXMetric;
 use crate::simulation::investment::appraisal::{
     AppraisalOutput, coefficients::ObjectiveCoefficients,
 };
@@ -360,8 +361,7 @@ pub fn appraisal_output(asset: Asset, time_slice: TimeSliceID) -> AppraisalOutpu
         activity,
         demand,
         unmet_demand,
-        metric_precedence: 0,
-        metric: 4.14,
+        metric: Box::new(LCOXMetric::new(4.14)),
     }
 }
 

src/output.rs

@@ -453,7 +453,7 @@ impl DebugDataWriter {
                 region_id: result.asset.region_id().clone(),
                 capacity: result.capacity,
                 capacity_coefficient: result.coefficients.capacity_coefficient,
-                metric: result.metric,
+                metric: result.metric.value(),
             };
             self.appraisal_results_writer.serialize(row)?;
         }

src/simulation/investment.rs

@@ -8,7 +8,6 @@ use crate::model::Model;
 use crate::output::DataWriter;
 use crate::region::RegionID;
 use crate::simulation::CommodityPrices;
-use crate::simulation::investment::appraisal::filter_for_minimum_precedence;
 use crate::time_slice::{TimeSliceID, TimeSliceInfo};
 use crate::units::{Capacity, Dimensionless, Flow, FlowPerCapacity};
 use anyhow::{Context, Result, bail, ensure};
@@ -719,9 +718,6 @@ fn select_best_assets(
             outputs_for_opts.push(output);
         }
 
-        // discard any appraisals with non-minimal metric precedence
-        outputs_for_opts = filter_for_minimum_precedence(outputs_for_opts);
-
         // Save appraisal results
         writer.write_appraisal_debug_info(
             year,