Cosmetic improvements

Hide transfers column in transposed report if no transfers
Report "Rollback complete" at end of stage when completed

src/constraints.rs

@@ -794,7 +794,7 @@ pub fn init_repeat_count_rollback<'a, N: Number>(state: &mut CountState<'a, N>,
 }
 
 /// Process one stage of rollback for [ConstraintMode::TwoStage]
-pub fn rollback_one_stage<N: Number>(state: &mut CountState<N>, opts: &STVOptions) -> Result<bool, STVError>
+pub fn rollback_one_stage<N: Number>(state: &mut CountState<N>, opts: &STVOptions) -> Result<(), STVError>
 where
 	for<'r> &'r N: ops::Add<&'r N, Output=N>,
 	for<'r> &'r N: ops::Sub<&'r N, Output=N>,
@@ -854,7 +854,7 @@ where
 		);
 		
 		state.rollback_state = RollbackState::RollingBack { candidates: Some(candidates), exhausted: exhausted.take(), candidate_distributing: None, constraint: Some(constraint), group: Some(group) };
-		return Ok(true);
+		return Ok(());
 	}
 	
 	if let RollbackState::RollingBack { candidates, exhausted, candidate_distributing, constraint, group } = &mut state.rollback_state {
@@ -904,7 +904,8 @@ where
 			}
 			
 			state.rollback_state = RollbackState::RollingBack { candidates: Some(candidates), exhausted: Some(exhausted), candidate_distributing, constraint: Some(constraint), group: Some(group) };
-			return Ok(true);
+			rollback_check_complete(state);
+			return Ok(());
 		}
 		
 		// ----------------------------------
@@ -933,7 +934,8 @@ where
 			exhausted.parcels.append(&mut dummy_count_card.parcels);
 			
 			state.rollback_state = RollbackState::RollingBack { candidates: Some(candidates), exhausted: Some(exhausted), candidate_distributing: None, constraint: Some(constraint), group: Some(group) };
-			return Ok(true);
+			rollback_check_complete(state);
+			return Ok(());
 		}
 		
 		// ------------------------------------------
@@ -989,7 +991,8 @@ where
 			stv::exclude_candidates(state, opts, vec![dummy_candidate], "Distribution")?;
 			
 			state.rollback_state = RollbackState::RollingBack { candidates: Some(candidates), exhausted: Some(exhausted), candidate_distributing: Some(candidate_distributing), constraint: Some(constraint), group: Some(group) };
-			return Ok(true);
+			rollback_check_complete(state);
+			return Ok(());
 		}
 		
 		// --------------------------------------------
@@ -1045,7 +1048,53 @@ where
 			stv::exclude_candidates(state, opts, vec![dummy_candidate], "Distribution")?;
 			
 			state.rollback_state = RollbackState::RollingBack { candidates: Some(candidates), exhausted: Some(exhausted), candidate_distributing: Some(candidate_distributing), constraint: Some(constraint), group: Some(group) };
-			return Ok(true);
+			rollback_check_complete(state);
+			return Ok(());
+		}
+	}
+	
+	unreachable!();
+}
+
+fn rollback_check_complete<N: Number>(state: &mut CountState<N>) {
+	if let RollbackState::RollingBack { candidates, exhausted, candidate_distributing: _, constraint: _, group: _ } = &state.rollback_state {
+		let candidates = candidates.as_ref().unwrap();
+		let exhausted = exhausted.as_ref().unwrap();
+		
+		let has_surplus: Vec<&Candidate> = state.election.candidates.iter() // Present in order in case of tie
+			.filter(|c| {
+				let cc = &candidates[c];
+				if !c.is_dummy && cc.state == CandidateState::Elected && !cc.finalised {
+					let dummy_candidate = state.election.candidates.iter().find(|x| x.name == c.name && x.is_dummy).unwrap();
+					!state.candidates[dummy_candidate].finalised
+				} else {
+					false
+				}
+			})
+			.collect();
+		
+		if !has_surplus.is_empty() {
+			return;
+		}
+		
+		if exhausted.parcels.iter().any(|p| !p.votes.is_empty()) {
+			return;
+		}
+		
+		let continuing_candidates: Vec<&Candidate> = state.election.candidates.iter()
+			.filter(|c| {
+				let cc = &candidates[c];
+				if !c.is_dummy && !cc.finalised {
+					let dummy_candidate = state.election.candidates.iter().find(|x| x.name == c.name && x.is_dummy).unwrap();
+					!state.candidates[dummy_candidate].finalised
+				} else {
+					false
+				}
+			})
+			.collect();
+		
+		if !continuing_candidates.is_empty() {
+			return;
 		}
 		
 		// ---------------------------
@@ -1065,7 +1114,7 @@ where
 		state.rollback_state = RollbackState::Normal;
 		state.num_excluded = state.candidates.values().filter(|cc| cc.state == CandidateState::Excluded).count();
 		
-		return Ok(false);
+		return;
 	}
 	
 	unreachable!();

src/stv/mod.rs

@@ -670,7 +670,8 @@ where
 	}
 	
 	if let RollbackState::Normal = state.rollback_state {
-	} else if constraints::rollback_one_stage(state, opts)? {
+	} else {
+		constraints::rollback_one_stage(state, opts)?;
 		elect_hopefuls(state, opts, true)?;
 		update_tiebreaks(state, opts);
 		return Ok(false);

src/stv/wasm.rs

@@ -406,6 +406,8 @@ pub fn update_results_table<N: Number>(stage_num: usize, state: &CountState<N>,
 		hide_xfers_trsp = true;
 	} else if let StageKind::BulkElection = state.title {
 		hide_xfers_trsp = true;
+	} else if state.candidates.values().all(|cc| cc.transfers.is_zero()) && state.exhausted.transfers.is_zero() && state.loss_fraction.transfers.is_zero() {
+		hide_xfers_trsp = true;
 	} else {
 		hide_xfers_trsp = false;
 	}