Implement --quota, --quota-criterion

src/main.rs

@@ -77,11 +77,22 @@ struct STV {
 	#[clap(help_heading=Some("ROUNDING"), long, value_name="dps")]
 	round_quota: Option<usize>,
 	
+	// -----------
+	// -- Quota --
+	
+	/// Quota type
+	#[clap(help_heading=Some("QUOTA"), short, long, possible_values=&["droop", "hare", "droop_exact", "hare_exact"], default_value="droop_exact")]
+	quota: String,
+	
+	/// Whether to elect candidates on meeting (geq) or strictly exceeding (gt) the quota
+	#[clap(help_heading=Some("QUOTA"), short='c', long, possible_values=&["geq", "gt"], default_value="gt", value_name="criterion")]
+	quota_criterion: String,
+	
 	// ------------------
 	// -- STV variants --
 	
 	/// Method of surplus transfers
-	#[clap(help_heading=Some("STV VARIANTS"), long, possible_values=&["wig", "uig", "eg", "meek"], default_value="wig", value_name="method")]
+	#[clap(help_heading=Some("STV VARIANTS"), short='s', long, possible_values=&["wig", "uig", "eg", "meek"], default_value="wig", value_name="method")]
 	surplus: String,
 	
 	#[clap(help_heading=Some("STV VARIANTS"), long, possible_values=&["by_size", "by_order"], default_value="by_size", value_name="order")]
@@ -142,6 +153,8 @@ where
 		cmd_opts.round_weights,
 		cmd_opts.round_votes,
 		cmd_opts.round_quota,
+		&cmd_opts.quota,
+		&cmd_opts.quota_criterion,
 		&cmd_opts.surplus,
 		&cmd_opts.surplus_order,
 		cmd_opts.transferable_only,

src/numbers/mod.rs

@@ -47,6 +47,7 @@ where
 	
 	fn pow_assign(&mut self, exponent: i32);
 	fn floor_mut(&mut self, dps: usize);
+	fn ceil_mut(&mut self, dps: usize);
 	
 	fn parse(s: &str) -> Self {
 		if let Ok(value) = Self::from_str_radix(s, 10) {

src/numbers/native.rs

@@ -39,6 +39,11 @@ impl Number for NativeFloat64 {
 		let factor = 10.0_f64.powi(dps as i32);
 		self.0 = (self.0 * factor).floor() / factor;
 	}
+	
+	fn ceil_mut(&mut self, dps: usize) {
+		let factor = 10.0_f64.powi(dps as i32);
+		self.0 = (self.0 * factor).ceil() / factor;
+	}
 }
 
 impl Num for NativeFloat64 {

src/numbers/rational_num.rs

@@ -44,6 +44,17 @@ impl Number for Rational {
 			self.0 /= factor;
 		}
 	}
+	
+	fn ceil_mut(&mut self, dps: usize) {
+		if dps == 0 {
+			self.0 = self.0.ceil();
+		} else {
+			let factor = BigRational::from_integer(BigInt::from(10)).pow(dps as i32);
+			self.0 *= &factor;
+			self.0 = self.0.ceil();
+			self.0 /= factor;
+		}
+	}
 }
 
 impl Num for Rational {

src/numbers/rational_rug.rs

@@ -44,6 +44,17 @@ impl Number for Rational {
 			self.0 /= factor;
 		}
 	}
+	
+	fn ceil_mut(&mut self, dps: usize) {
+		if dps == 0 {
+			self.0.ceil_mut();
+		} else {
+			let factor = rug::Rational::from(10).pow(dps as u32);
+			self.0 *= &factor;
+			self.0.ceil_mut();
+			self.0 /= factor;
+		}
+	}
 }
 
 impl Num for Rational {

src/stv/mod.rs

@@ -34,6 +34,8 @@ pub struct STVOptions {
 	pub round_weights: Option<usize>,
 	pub round_votes: Option<usize>,
 	pub round_quota: Option<usize>,
+	pub quota: QuotaType,
+	pub quota_criterion: QuotaCriterion,
 	pub surplus: SurplusMethod,
 	pub surplus_order: SurplusOrder,
 	pub transferable_only: bool,
@@ -48,6 +50,8 @@ impl STVOptions {
 		round_weights: Option<usize>,
 		round_votes: Option<usize>,
 		round_quota: Option<usize>,
+		quota: &str,
+		quota_criterion: &str,
 		surplus: &str,
 		surplus_order: &str,
 		transferable_only: bool,
@@ -59,6 +63,18 @@ impl STVOptions {
 			round_weights,
 			round_votes,
 			round_quota,
+			quota: match quota {
+				"droop" => QuotaType::Droop,
+				"hare" => QuotaType::Hare,
+				"droop_exact" => QuotaType::DroopExact,
+				"hare_exact" => QuotaType::HareExact,
+				_ => panic!("Invalid --quota"),
+			},
+			quota_criterion: match quota_criterion {
+				"geq" => QuotaCriterion::GreaterOrEqual,
+				"gt" => QuotaCriterion::Greater,
+				_ => panic!("Invalid --quota-criterion"),
+			},
 			surplus: match surplus {
 				"wig" => SurplusMethod::WIG,
 				"uig" => SurplusMethod::UIG,
@@ -83,6 +99,22 @@ impl STVOptions {
 	}
 }
 
+#[wasm_bindgen]
+#[derive(Clone, Copy)]
+pub enum QuotaType {
+	Droop,
+	Hare,
+	DroopExact,
+	HareExact,
+}
+
+#[wasm_bindgen]
+#[derive(Clone, Copy)]
+pub enum QuotaCriterion {
+	GreaterOrEqual,
+	Greater,
+}
+
 #[wasm_bindgen]
 #[derive(Clone, Copy)]
 pub enum SurplusMethod {
@@ -110,7 +142,7 @@ pub enum ExclusionMethod {
 pub fn count_init<N: Number>(mut state: &mut CountState<'_, N>, opts: &STVOptions) {
 	distribute_first_preferences(&mut state);
 	calculate_quota(&mut state, opts);
-	elect_meeting_quota(&mut state);
+	elect_meeting_quota(&mut state, opts);
 }
 
 pub fn count_one_stage<N: Number>(mut state: &mut CountState<'_, N>, opts: &STVOptions) -> bool
@@ -129,25 +161,25 @@ where
 	
 	// Continue exclusions
 	if continue_exclusion(&mut state, &opts) {
-		elect_meeting_quota(&mut state);
+		elect_meeting_quota(&mut state, opts);
 		return false;
 	}
 	
 	// Distribute surpluses
 	if distribute_surpluses(&mut state, &opts) {
-		elect_meeting_quota(&mut state);
+		elect_meeting_quota(&mut state, opts);
 		return false;
 	}
 	
 	// Attempt bulk election
 	if bulk_elect(&mut state) {
-		elect_meeting_quota(&mut state);
+		elect_meeting_quota(&mut state, opts);
 		return false;
 	}
 	
 	// Exclude lowest hopeful
 	if exclude_hopefuls(&mut state, &opts) {
-		elect_meeting_quota(&mut state);
+		elect_meeting_quota(&mut state, opts);
 		return false;
 	}
 	
@@ -256,17 +288,35 @@ fn calculate_quota<N: Number>(state: &mut CountState<N>, opts: &STVOptions) {
 	state.quota = state.candidates.values().fold(N::zero(), |acc, cc| { acc + &cc.votes });
 	log.push_str(format!("{:.dps$} usable votes, so the quota is ", state.quota, dps=opts.pp_decimals).as_str());
 	
-	// TODO: Different quotas
-	state.quota /= N::from(state.election.seats + 1);
+	match opts.quota {
+		QuotaType::Droop | QuotaType::DroopExact => {
+			state.quota /= N::from(state.election.seats + 1);
+		}
+		QuotaType::Hare | QuotaType::HareExact => {
+			state.quota /= N::from(state.election.seats);
+		}
+	}
 	
-	// Increment to next available increment
 	if let Some(dps) = opts.round_quota {
-		let mut factor = N::from(10);
-		factor.pow_assign(dps as i32);
-		state.quota *= &factor;
-		state.quota.floor_mut(0);
-		state.quota += N::one();
-		state.quota /= factor;
+		match opts.quota {
+			QuotaType::Droop | QuotaType::Hare => {
+				// Increment to next available increment
+				let mut factor = N::from(10);
+				factor.pow_assign(dps as i32);
+				state.quota *= &factor;
+				state.quota.floor_mut(0);
+				state.quota += N::one();
+				state.quota /= factor;
+			}
+			QuotaType::DroopExact | QuotaType::HareExact => {
+				// Round up to next available increment if necessary
+				let mut factor = N::from(10);
+				factor.pow_assign(dps as i32);
+				state.quota *= &factor;
+				state.quota.ceil_mut(0);
+				state.quota /= factor;
+			}
+		}
 	}
 	
 	log.push_str(format!("{:.dps$}.", state.quota, dps=opts.pp_decimals).as_str());
@@ -274,15 +324,21 @@ fn calculate_quota<N: Number>(state: &mut CountState<N>, opts: &STVOptions) {
 	state.logger.log_literal(log);
 }
 
-fn meets_quota<N: Number>(quota: &N, count_card: &CountCard<N>) -> bool {
-	// TODO: Different quota rules
-	return count_card.votes >= *quota;
+fn meets_quota<N: Number>(quota: &N, count_card: &CountCard<N>, opts: &STVOptions) -> bool {
+	match opts.quota_criterion {
+		QuotaCriterion::GreaterOrEqual => {
+			return count_card.votes >= *quota;
+		}
+		QuotaCriterion::Greater => {
+			return count_card.votes > *quota;
+		}
+	}
 }
 
-fn elect_meeting_quota<N: Number>(state: &mut CountState<N>) {
+fn elect_meeting_quota<N: Number>(state: &mut CountState<N>, opts: &STVOptions) {
 	let quota = &state.quota; // Have to do this or else the borrow checker gets confused
 	let mut cands_meeting_quota: Vec<(&&Candidate, &mut CountCard<N>)> = state.candidates.iter_mut()
-		.filter(|(_, cc)| cc.state == CandidateState::HOPEFUL && meets_quota(quota, cc))
+		.filter(|(_, cc)| cc.state == CandidateState::HOPEFUL && meets_quota(quota, cc, opts))
 		.collect();
 	
 	if cands_meeting_quota.len() > 0 {

tests/aec.rs

@@ -59,6 +59,8 @@ fn aec_tas19_rational() {
 		round_weights: None,
 		round_votes: Some(0),
 		round_quota: Some(0),
+		quota: stv::QuotaType::Droop,
+		quota_criterion: stv::QuotaCriterion::GreaterOrEqual,
 		surplus: stv::SurplusMethod::UIG,
 		surplus_order: stv::SurplusOrder::ByOrder,
 		transferable_only: false,

tests/prsa.rs

@@ -27,6 +27,8 @@ fn prsa1_rational() {
 		round_weights: Some(3),
 		round_votes: Some(3),
 		round_quota: Some(3),
+		quota: stv::QuotaType::Droop,
+		quota_criterion: stv::QuotaCriterion::GreaterOrEqual,
 		surplus: stv::SurplusMethod::EG,
 		surplus_order: stv::SurplusOrder::ByOrder,
 		transferable_only: true,