Implement Scottish STV test case

Cargo.lock

@@ -345,6 +345,7 @@ dependencies = [
  "paste",
  "rug",
  "wasm-bindgen",
+ "xmltree",
 ]
 
 [[package]]
@@ -576,3 +577,18 @@ name = "winapi-x86_64-pc-windows-gnu"
 version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
+
+[[package]]
+name = "xml-rs"
+version = "0.8.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b07db065a5cf61a7e4ba64f29e67db906fb1787316516c4e6e5ff0fea1efcd8a"
+
+[[package]]
+name = "xmltree"
+version = "0.10.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d7d8a75eaf6557bb84a65ace8609883db44a29951042ada9b393151532e41fcb"
+dependencies = [
+ "xml-rs",
+]

Cargo.toml

@@ -25,6 +25,7 @@ paste = "1.0.5"
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 csv = "1.1.6"
 flate2 = "1.0"
+xmltree = "0.10.3"
 
 [target.'cfg(not(target_arch = "wasm32"))'.dependencies.rug]
 version = "1.12"

html/main.css

@@ -109,7 +109,7 @@ tr.info:last-child td, .bb {
 
 /* Table stripes */
 
-tr.stage-no td:nth-child(even),
+tr.stage-no td:nth-child(even):not([rowspan]),
 tr.stage-comment td:nth-child(odd),
 tr.candidate.transfers td:nth-child(even):not(.elected):not(.excluded),
 tr.candidate.votes td:nth-child(odd):not(.elected):not(.excluded) {

src/numbers/fixed.rs

@@ -103,7 +103,7 @@ impl From<usize> for Fixed {
 
 impl From<f64> for Fixed {
 	fn from(n: f64) -> Self {
-		return Self(IBig::from((n * 10_f64.powi(get_dps() as i32)) as u32))
+		return Self(IBig::from((n * 10_f64.powi(get_dps() as i32)).round() as u32))
 	}
 }
 

tests/scotland.rs

@@ -0,0 +1,152 @@
+/*  OpenTally: Open-source election vote counting
+ *  Copyright © 2021 Lee Yingtong Li (RunasSudo)
+ *
+ *  This program is free software: you can redistribute it and/or modify
+ *  it under the terms of the GNU Affero General Public License as published by
+ *  the Free Software Foundation, either version 3 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU Affero General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Affero General Public License
+ *  along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+// https://web.archive.org/web/20121004213938/http://www.glasgow.gov.uk/en/YourCouncil/Elections_Voting/Election_Results/ElectionScotland2007/LGWardResults.htm?ward=1&wardname=1%20-%20Linn
+
+use opentally::election::{CandidateState, CountState, Election};
+use opentally::numbers::Fixed;
+use opentally::stv;
+
+use num_traits::Zero;
+use xmltree::Element;
+
+use std::io::{self, BufRead};
+use std::fs::File;
+
+#[test]
+fn scotland_linn07_fixed5() {
+	let stv_opts = stv::STVOptions {
+		round_tvs: Some(5),
+		round_weights: None,
+		round_votes: None,
+		round_quota: Some(0),
+		quota: stv::QuotaType::Droop,
+		quota_criterion: stv::QuotaCriterion::GreaterOrEqual,
+		quota_mode: stv::QuotaMode::Static,
+		surplus: stv::SurplusMethod::WIG,
+		surplus_order: stv::SurplusOrder::BySize,
+		transferable_only: false,
+		exclusion: stv::ExclusionMethod::SingleStage,
+		bulk_exclude: false,
+		defer_surpluses: false,
+		pp_decimals: 5,
+	};
+	Fixed::set_dps(5);
+	
+	// Read XML file
+	let file = File::open("tests/data/linn07.xml").expect("IO Error");
+	let root = Element::parse(file).expect("Parse Error");
+	
+	let mut candidates: Vec<&Element> = root.children.iter()
+		.filter_map(|n| match n {
+			xmltree::XMLNode::Element(e) => if e.name == "candidate" { Some(e) } else { None },
+			_ => None,
+		})
+		.collect();
+	let cand_nt = candidates.pop().unwrap();
+	
+	// TODO: Validate candidate names
+	
+	let num_stages = root.get_child("headerrow").expect("Syntax Error").children.len();
+	
+	// Read BLT
+	let file = File::open("tests/data/linn07.blt").expect("IO Error");
+	let file_reader = io::BufReader::new(file);
+	let lines = file_reader.lines();
+	
+	let election: Election<Fixed> = Election::from_blt(lines.map(|r| r.expect("IO Error").to_string()).into_iter());
+	
+	// Initialise count state
+	let mut state = CountState::new(&election);
+	
+	// Distribute first preferences
+	stv::count_init(&mut state, &stv_opts);
+	let mut stage_num = 1;
+	
+	for i in 0..num_stages {
+		println!("Stage {}", stage_num);
+		
+		// Validate NT
+		let nt_votes = get_cand_stage(cand_nt, i)
+			.get_child("value").unwrap()
+			.get_text().unwrap()
+			.to_string();
+		
+		assert!(approx_eq(&(&state.exhausted.votes + &state.loss_fraction.votes), &parse_str(nt_votes)));
+		
+		for (candidate, cand_xml) in state.election.candidates.iter().zip(candidates.iter()) {
+			let count_card = state.candidates.get(candidate).unwrap();
+			
+			// Validate candidate votes
+			let cand_votes = get_cand_stage(cand_xml, i)
+				.get_child("value").unwrap()
+				.get_text().unwrap()
+				.to_string();
+			let cand_votes = parse_str(cand_votes);
+			assert!(approx_eq(&count_card.votes, &cand_votes), "Failed to validate votes for candidate {}. Expected {:}, got {:}", candidate.name, cand_votes, count_card.votes);
+			
+			// Validate candidate states
+			let cand_state = get_cand_stage(cand_xml, i)
+				.get_child("status").unwrap()
+				.get_text().unwrap()
+				.to_string();
+			if cand_state == "Continuing" {
+				assert!(count_card.state == CandidateState::HOPEFUL);
+			} else if cand_state == "Elected" {
+				assert!(count_card.state == CandidateState::ELECTED);
+			} else if cand_state == "Excluded" {
+				assert!(count_card.state == CandidateState::EXCLUDED);
+			} else {
+				panic!("Unknown state descriptor {}", cand_state);
+			}
+		}
+		
+		assert_eq!(stv::count_one_stage(&mut state, &stv_opts), false);
+		stage_num += 1;
+	}
+	
+	assert_eq!(stv::count_one_stage(&mut state, &stv_opts), true);
+}
+
+fn get_cand_stage(candidate: &Element, idx: usize) -> &Element {
+	return candidate.children.iter()
+		.filter_map(|n| match n {
+			xmltree::XMLNode::Element(e) => if e.name == "stage" { Some(e) } else { None },
+			_ => None,
+		})
+		.nth(idx).unwrap();
+}
+
+fn parse_str(s: String) -> Fixed {
+	if s == "-" { return Fixed::zero(); }
+	let f: f64 = s.parse().expect("Syntax Error");
+	return opentally::numbers::From::from(f);
+}
+
+fn approx_eq(a: &Fixed, b: &Fixed) -> bool {
+	// Some tolerance required in equality comparisons, as eSTV incorrectly computes transfers
+	// by value, instead of all at once, resulting in increased rounding error
+	let eq_tol: Fixed = opentally::numbers::From::from(0.0001);
+	
+	if a - b > eq_tol {
+		return false;
+	}
+	if b - a > eq_tol {
+		return false;
+	}
+	return true;
+}