RunasSudo/OpenTally
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Validate well-formedness of constraints, better constraint errors

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This commit is contained in:
RunasSudo 2021-10-29 23:07:38 +11:00
parent ba82828046
commit 6304e1128a
Signed by: RunasSudo
GPG Key ID: 7234E476BF21C61A
5 changed files with 168 additions and 29 deletions
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30
src/cli/stv.rs
View File

@ -203,25 +203,25 @@ pub fn main(cmd_opts: SubcmdOptions) -> Result<(), i32> {
// Read and count election according to --numbers
if cmd_opts.numbers == "rational" {
let mut election = election_from_file(&cmd_opts.filename, cmd_opts.bin)?;
maybe_load_constraints(&mut election, &cmd_opts.constraints);
maybe_load_constraints(&mut election, &cmd_opts.constraints)?;
// Must specify ::<N> here and in a few other places because ndarray causes E0275 otherwise
count_election::<Rational>(election, cmd_opts)?;
} else if cmd_opts.numbers == "float64" {
let mut election = election_from_file(&cmd_opts.filename, cmd_opts.bin)?;
maybe_load_constraints(&mut election, &cmd_opts.constraints);
maybe_load_constraints(&mut election, &cmd_opts.constraints)?;
count_election::<NativeFloat64>(election, cmd_opts)?;
} else if cmd_opts.numbers == "fixed" {
Fixed::set_dps(cmd_opts.decimals);
let mut election = election_from_file(&cmd_opts.filename, cmd_opts.bin)?;
maybe_load_constraints(&mut election, &cmd_opts.constraints);
maybe_load_constraints(&mut election, &cmd_opts.constraints)?;
count_election::<Fixed>(election, cmd_opts)?;
} else if cmd_opts.numbers == "gfixed" {
GuardedFixed::set_dps(cmd_opts.decimals);
let mut election = election_from_file(&cmd_opts.filename, cmd_opts.bin)?;
maybe_load_constraints(&mut election, &cmd_opts.constraints);
maybe_load_constraints(&mut election, &cmd_opts.constraints)?;
count_election::<GuardedFixed>(election, cmd_opts)?;
}
@ -244,12 +244,30 @@ fn election_from_file<N: Number>(path: &str, bin: bool) -> Result<Election<N>, i
}
}
fn maybe_load_constraints<N: Number>(election: &mut Election<N>, constraints: &Option<String>) {
fn maybe_load_constraints<N: Number>(election: &mut Election<N>, constraints: &Option<String>) -> Result<(), i32> {
if let Some(c) = constraints {
let file = File::open(c).expect("IO Error");
let lines = io::BufReader::new(file).lines();
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error"))));
let lines: Vec<_> = lines.map(|r| r.expect("IO Error")).collect();
match Constraints::from_con(lines.into_iter()) {
Ok(c) => {
election.constraints = Some(c);
}
Err(err) => {
println!("Constraint Syntax Error: {}", err);
return Err(1);
}
}
// Validate constraints
if let Err(err) = election.constraints.as_ref().unwrap().validate_constraints(election.candidates.len()) {
println!("Constraint Validation Error: {}", err);
return Err(1);
}
}
Ok(())
}
fn count_election<N: Number>(election: Election<N>, cmd_opts: SubcmdOptions) -> Result<(), i32>

150
src/constraints.rs
View File

@ -27,6 +27,7 @@ use rkyv::{Archive, Deserialize, Serialize};
use std::collections::HashMap;
use std::fmt;
use std::num::ParseIntError;
use std::ops;
/// Constraints for an [crate::election::Election]
@ -36,24 +37,28 @@ pub struct Constraints(pub Vec<Constraint>);
impl Constraints {
/// Parse the given CON file and return a [Constraints]
pub fn from_con<I: Iterator<Item=String>>(lines: I) -> Self {
pub fn from_con<S: AsRef<str>, I: Iterator<Item=S>>(lines: I) -> Result<Self, ParseError> {
let mut constraints = Constraints(Vec::new());
for line in lines {
let mut bits = line.split(' ').peekable();
for (line_no, line) in lines.enumerate() {
let mut bits = line.as_ref().split(' ').peekable();
// Read constraint category and group
let constraint_name = read_quoted_string(&mut bits);
let group_name = read_quoted_string(&mut bits);
let constraint_name = read_quoted_string(line_no, &mut bits)?;
let group_name = read_quoted_string(line_no, &mut bits)?;
// Read min, max
let min: usize = bits.next().expect("Syntax Error").parse().expect("Syntax Error");
let max: usize = bits.next().expect("Syntax Error").parse().expect("Syntax Error");
let min: usize = bits
.next().ok_or(ParseError::UnexpectedEOL(line_no, "minimum number"))?
.parse().map_err(|e| ParseError::InvalidNumber(line_no, e))?;
let max: usize = bits
.next().ok_or(ParseError::UnexpectedEOL(line_no, "maximum number"))?
.parse().map_err(|e| ParseError::InvalidNumber(line_no, e))?;
// Read candidates
let mut candidates: Vec<usize> = Vec::new();
for x in bits {
candidates.push(x.parse::<usize>().expect("Syntax Error") - 1);
candidates.push(x.parse::<usize>().map_err(|e| ParseError::InvalidNumber(line_no, e))? - 1);
}
// Insert constraint/group
@ -70,7 +75,7 @@ impl Constraints {
};
if constraint.groups.iter().any(|g| g.name == group_name) {
panic!("Duplicate group \"{}\" in constraint \"{}\"", group_name, constraint.name);
return Err(ParseError::DuplicateGroup(line_no, group_name, constraint.name.clone()));
}
constraint.groups.push(ConstrainedGroup {
@ -81,26 +86,132 @@ impl Constraints {
});
}
// TODO: Validate constraints
return constraints;
return Ok(constraints);
}
/// Validate that each candidate is specified exactly once in each constraint
pub fn validate_constraints(&self, num_candidates: usize) -> Result<(), ValidationError> {
for constraint in &self.0 {
let mut remaining_candidates: Vec<usize> = (0..num_candidates).collect();
for group in &constraint.groups {
for candidate in &group.candidates {
match remaining_candidates.iter().position(|c| c == candidate) {
Some(idx) => {
remaining_candidates.remove(idx);
}
None => {
return Err(ValidationError::DuplicateCandidate(*candidate, constraint.name.clone()));
}
}
}
}
if !remaining_candidates.is_empty() {
return Err(ValidationError::UnassignedCandidate(*remaining_candidates.first().unwrap(), constraint.name.clone()));
}
}
Ok(())
}
}
/// Error parsing constraints
pub enum ParseError {
/// Duplicate group in a constraint
DuplicateGroup(usize, String, String),
/// Unexpected EOL, expected ...
UnexpectedEOL(usize, &'static str),
/// Invalid number
InvalidNumber(usize, ParseIntError),
}
impl fmt::Display for ParseError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
ParseError::DuplicateGroup(line_no, group_name, constraint_name) => {
f.write_fmt(format_args!(r#"Line {}, duplicate group "{}" in constraint "{}""#, line_no, group_name, constraint_name))
}
ParseError::UnexpectedEOL(line_no, expected) => {
f.write_fmt(format_args!(r#"Line {}, unexpected end-of-line, expected {}"#, line_no, expected))
}
ParseError::InvalidNumber(line_no, err) => {
f.write_fmt(format_args!(r#"Line {}, invalid number: {}"#, line_no, err))
}
}
}
}
impl fmt::Debug for ParseError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
return fmt::Display::fmt(self, f);
}
}
/// Error validating constraints
pub enum ValidationError {
/// Duplicate candidate in a constraint
DuplicateCandidate(usize, String),
/// Unassigned candidate in a constraint
UnassignedCandidate(usize, String),
}
impl fmt::Display for ValidationError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
match self {
ValidationError::DuplicateCandidate(candidate, constraint_name) => {
f.write_fmt(format_args!(r#"Duplicate candidate {} in constraint "{}""#, candidate + 1, constraint_name))
}
ValidationError::UnassignedCandidate(candidate, constraint_name) => {
f.write_fmt(format_args!(r#"Unassigned candidate {} in constraint "{}""#, candidate + 1, constraint_name))
}
}
}
}
impl fmt::Debug for ValidationError {
fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
return fmt::Display::fmt(self, f);
}
}
#[test]
fn duplicate_contraint_group() {
let input = r#""Constraint 1" "Group 1" 0 3 1 2 3
"Constraint 1" "Group 1" 0 3 4 5 6"#;
Constraints::from_con(input.lines()).unwrap_err();
}
#[test]
fn duplicate_candidate() {
let input = r#""Constraint 1" "Group 1" 0 3 1 2 3 4
"Constraint 1" "Group 2" 0 3 4 5 6"#;
let constraints = Constraints::from_con(input.lines()).unwrap();
constraints.validate_constraints(6).unwrap_err();
}
#[test]
fn unassigned_candidate() {
let input = r#""Constraint 1" "Group 1" 0 3 1 2 3
"Constraint 1" "Group 2" 0 3 4 5 6"#;
let constraints = Constraints::from_con(input.lines()).unwrap();
constraints.validate_constraints(7).unwrap_err();
}
/// Read an optionally quoted string, returning the string without quotes
fn read_quoted_string<'a, I: Iterator<Item=&'a str>>(bits: &mut I) -> String {
let x = bits.next().expect("Syntax Error");
fn read_quoted_string<'a, I: Iterator<Item=&'a str>>(line_no: usize, bits: &mut I) -> Result<String, ParseError> {
let x = bits.next().ok_or(ParseError::UnexpectedEOL(line_no, "string continuation"))?;
if let Some(x1) = x.strip_prefix('"') {
if let Some(x2) = x.strip_suffix('"') {
// Complete string
return String::from(x2);
return Ok(String::from(x2));
} else {
// Incomplete string
let mut result = String::from(x1);
// Read until matching "
loop {
let x = bits.next().expect("Syntax Error");
let x = bits.next().ok_or(ParseError::UnexpectedEOL(line_no, "string continuation"))?;
result.push(' ');
if let Some(x1) = x.strip_suffix('"') {
// End of string
@ -112,11 +223,11 @@ fn read_quoted_string<'a, I: Iterator<Item=&'a str>>(bits: &mut I) -> String {
}
}
return result;
return Ok(result);
}
} else {
// Unquoted string
return String::from(x);
return Ok(String::from(x));
}
}
@ -227,7 +338,8 @@ impl ConstraintMatrix {
return j + 1;
}
}
panic!("Candidate \"{}\" not represented in constraint \"{}\"", candidate.name, c.name);
// Should be caught by validate_constraints
unreachable!("Candidate \"{}\" not represented in constraint \"{}\"", candidate.name, c.name);
}).collect();
let cell = &mut self[&idx[..]];

1
src/election.rs
View File

@ -179,6 +179,7 @@ impl<'a, N: Number> CountState<'a, N> {
// Init constraints
if let Some(constraints) = &election.constraints {
// Init constraint matrix
let mut num_groups: Vec<usize> = constraints.0.iter().map(|c| c.groups.len()).collect();
let mut cm = ConstraintMatrix::new(&mut num_groups[..]);

10
src/stv/wasm.rs
View File

@ -92,7 +92,15 @@ macro_rules! impl_type {
#[cfg_attr(feature = "wasm", wasm_bindgen)]
#[allow(non_snake_case)]
pub fn [<election_load_constraints_$type>](election: &mut [<Election$type>], text: String) {
election.0.constraints = Some(Constraints::from_con(text.lines().map(|s| s.to_string()).into_iter()));
election.0.constraints = match Constraints::from_con(text.lines()) {
Ok(c) => Some(c),
Err(err) => wasm_error!("Constraint Syntax Error", err),
};
// Validate constraints
if let Err(err) = election.0.constraints.as_ref().unwrap().validate_constraints(election.0.candidates.len()) {
wasm_error!("Constraint Validation Error", err);
}
}
/// Wrapper for [stv::preprocess_election]

8
tests/tests_impl/constraints.rs
View File

@ -37,7 +37,7 @@ fn prsa1_constr1_rational() {
let file = File::open("tests/data/prsa1_constr1.con").expect("IO Error");
let file_reader = io::BufReader::new(file);
let lines = file_reader.lines();
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()));
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()).unwrap());
let stv_opts = stv::STVOptionsBuilder::default()
.round_surplus_fractions(Some(3))
@ -86,7 +86,7 @@ fn prsa1_constr2_rational() {
let file = File::open("tests/data/prsa1_constr2.con").expect("IO Error");
let file_reader = io::BufReader::new(file);
let lines = file_reader.lines();
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()));
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()).unwrap());
let stv_opts = stv::STVOptionsBuilder::default()
.round_surplus_fractions(Some(3))
@ -135,7 +135,7 @@ fn prsa1_constr3_rational() {
let file = File::open("tests/data/prsa1_constr3.con").expect("IO Error");
let file_reader = io::BufReader::new(file);
let lines = file_reader.lines();
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()));
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()).unwrap());
let stv_opts = stv::STVOptionsBuilder::default()
.round_surplus_fractions(Some(3))
@ -196,7 +196,7 @@ fn ers97old_cantbulkexclude_rational() {
let file = File::open("tests/data/ers97old_cantbulkexclude.con").expect("IO Error");
let file_reader = io::BufReader::new(file);
let lines = file_reader.lines();
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()));
election.constraints = Some(Constraints::from_con(lines.map(|r| r.expect("IO Error").to_string()).into_iter()).unwrap());
let stv_opts = stv::STVOptionsBuilder::default()
.round_surplus_fractions(Some(2))