Grcov report - sat_order

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// https://conjure-cp.github.io/conjure-oxide/docs/conjure_core/representation/trait.Representation.html

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use conjure_cp::ast::GroundDomain;

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use conjure_cp::bug;

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use conjure_cp::{

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    ast::{Atom, DeclarationPtr, Domain, Expression, Literal, Metadata, Name, SymbolTable},

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    register_representation,

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    representation::Representation,

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    rule_engine::ApplicationError,

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};

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register_representation!(SatOrderInt, "sat_order_int");

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#[derive(Clone, Debug)]

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pub struct SatOrderInt {

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    src_var: Name,

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    upper_bound: i32,

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    lower_bound: i32,

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impl SatOrderInt {

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    /// Returns the names of the boolean variables used in the order encoding.

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    fn names(&self) -> impl Iterator<Item = Name> + '_ {

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        (self.lower_bound..self.upper_bound).map(move |index| self.index_to_name(index))

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    /// Gets the representation variable name corresponding to a concrete integer value.

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    fn index_to_name(&self, index: i32) -> Name {

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        Name::Represented(Box::new((

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            self.src_var.clone(),

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            self.repr_name().into(),

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            format!("{index:02}").into(), // stored as _00, _01, ...

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)))

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impl Representation for SatOrderInt {

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    /// Creates a order int representation object for the given name.

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    fn init(name: &Name, symtab: &SymbolTable) -> Option<Self> {

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        let domain = symtab.resolve_domain(name)?;

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        if !domain.is_finite() {

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            return None;

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        let GroundDomain::Int(ranges) = domain.as_ref() else {

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            return None;

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};

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        // Determine min/max and return None if range is unbounded

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        let (min, max) =

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            ranges

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                .iter()

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                .try_fold((i32::MAX, i32::MIN), |(min_a, max_b), range| {

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                    let lb = range.low()?;

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                    let ub = range.high()?;

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                    Some((min_a.min(*lb), max_b.max(*ub)))

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                })?;

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        Some(SatOrderInt {

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            src_var: name.clone(),

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            lower_bound: min,

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            upper_bound: max + 1,

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})

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    /// The variable being represented.

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    fn variable_name(&self) -> &Name {

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        &self.src_var

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    fn value_down(

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        &self,

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        _value: Literal,

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    ) -> Result<std::collections::BTreeMap<Name, Literal>, ApplicationError> {

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        // NOTE: It's unclear where and when `value_down` would be called for

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        // order encoding. This is also never called in log encoding, so we

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        // deliberately fail here to surface unexpected usage.

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        bug!("value_down is not implemented for order encoding and should not be called")

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    /// Given the values for its boolean representation variables, creates an assignment for `self` - the integer form.

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    fn value_up(

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        &self,

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        values: &std::collections::BTreeMap<Name, Literal>,

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    ) -> Result<Literal, ApplicationError> {

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        let mut first_false_candidate: Option<i32> = None;

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        for value_candidate in self.lower_bound..self.upper_bound {

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            let name = self.index_to_name(value_candidate);

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            let value_literal = values

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                .get(&name)

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                .ok_or(ApplicationError::RuleNotApplicable)?;

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            let is_true = match value_literal {

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                Literal::Int(1) | Literal::Bool(true) => true,

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                Literal::Int(0) | Literal::Bool(false) => false,

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                _ => return Err(ApplicationError::RuleNotApplicable),

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};

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            if !is_true && first_false_candidate.is_none() {

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                first_false_candidate = Some(value_candidate);

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            if is_true && first_false_candidate.is_some() {

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                // we have a true after a false

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                return Err(ApplicationError::RuleNotApplicable);

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        if let Some(first_false) = first_false_candidate {

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            return Ok(Literal::Int(first_false - 1));

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        // if we are here, all are true. So the value is the last one.

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        Ok(Literal::Int(self.upper_bound - 1))

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    /// Returns [`Expression`]s representing each boolean representation variable.

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    fn expression_down(

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        &self,

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        st: &SymbolTable,

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    ) -> Result<std::collections::BTreeMap<Name, Expression>, ApplicationError> {

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        Ok(self

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            .names()

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            .enumerate()

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            .map(|(index, name)| {

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                let decl = st.lookup(&name).unwrap();

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                    // Machine names are used so that the derived ordering matches the correct ordering of the representation variables

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                    Name::Machine(index as i32),

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                    Expression::Atomic(

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                        Metadata::new(),

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                        Atom::Reference(conjure_cp::ast::Reference { ptr: decl }),

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),

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})

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            .collect())

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    /// Creates declarations for the boolean representation variables of `self`.

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    fn declaration_down(&self) -> Result<Vec<DeclarationPtr>, ApplicationError> {

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        let temp_a = self

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            .names()

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            .map(|name| DeclarationPtr::new_find(name, Domain::bool()))

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            .collect();

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        Ok(temp_a)

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    /// The rule name for this representation.

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    fn repr_name(&self) -> &str {

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        "sat_order_int"

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    /// Makes a clone of `self` into a `Representation` trait object.

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    fn box_clone(&self) -> Box<dyn Representation> {

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        Box::new(self.clone()) as _

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