pub fn model_from_json(str: &str, context: Arc<RwLock<Context<'static>>>) -> Result<Model> {

    let mut m = Model::new(context);

    let v: JsonValue = serde_json::from_str(str)?;

    let statements = v["mStatements"]

        .as_array()

        .ok_or(error!("mStatements is not an array"))?;

    for statement in statements {

        let entry = statement

            .as_object()

            .ok_or(error!("mStatements contains a non-object"))?

            .iter()

            .next()

            .ok_or(error!("mStatements contains an empty object"))?;

        match entry.0.as_str() {

            "Declaration" => {

                let decl = entry

                    .1

                    .as_object()

                    .ok_or(error!("Declaration is not an object".to_owned()))?;

                let mut valid_decl: bool = false;

                let scope = m.as_submodel().symbols_ptr_unchecked().clone();

                let submodel = m.as_submodel_mut();

                for (kind, value) in decl {

                    match kind.as_str() {

                        "FindOrGiven" => {

                            parse_variable(value, &mut submodel.symbols_mut())?;

                            valid_decl = true;

                            break;

                        "Letting" => {

                            parse_letting(value, &scope)?;

                            valid_decl = true;

                            break;

                        _ => continue,

                if !valid_decl {

                    throw_error!("Declaration is not a valid kind")?;

                }

            "SuchThat" => {

                let constraints_arr = match entry.1.as_array() {

                    Some(x) => x,

                let constraints: Vec<Expression> = constraints_arr

                    .iter()

                    .map(|x| {

                        parse_expression(x, m.as_submodel_mut().symbols_ptr_unchecked()).unwrap()

                    })

                    .collect();

                m.as_submodel_mut().add_constraints(constraints);

    Ok(m)

}

fn parse_variable(v: &JsonValue, symtab: &mut SymbolTable) -> Result<()> {

    let arr = v.as_array().ok_or(error!("FindOrGiven is not an array"))?;

    let name = arr[1]

        .as_object()

        .ok_or(error!("FindOrGiven[1] is not an object"))?["Name"]

        .as_str()

        .ok_or(error!("FindOrGiven[1].Name is not a string"))?;

    let name = Name::User(Ustr::from(name));

    let domain = arr[2]

        .as_object()

        .ok_or(error!("FindOrGiven[2] is not an object"))?

        .iter()

        .next()

        .ok_or(error!("FindOrGiven[2] is an empty object"))?;

    let domain = parse_domain(domain.0, domain.1, symtab)?;

    symtab

        .insert(DeclarationPtr::new_var(name.clone(), domain))

        .ok_or(Error::Parse(format!(

            "Could not add {name} to symbol table as it already exists"

        )))

}

fn parse_letting(v: &JsonValue, scope: &Rc<RefCell<SymbolTable>>) -> Result<()> {

    let arr = v.as_array().ok_or(error!("Letting is not an array"))?;

    let name = arr[0]

        .as_object()

        .ok_or(error!("Letting[0] is not an object"))?["Name"]

        .as_str()

        .ok_or(error!("Letting[0].Name is not a string"))?;

    let name = Name::User(Ustr::from(name));

    if let Some(value) = parse_expression(&arr[1], scope) {

        let mut symtab = scope.borrow_mut();

        symtab

            .insert(DeclarationPtr::new_value_letting(name.clone(), value))

            .ok_or(Error::Parse(format!(

                "Could not add {name} to symbol table as it already exists"

            )))

        let domain = &arr[1]

            .as_object()

            .ok_or(error!("Letting[1] is not an object".to_owned()))?["Domain"]

            .as_object()

            .ok_or(error!("Letting[1].Domain is not an object"))?

            .iter()

            .next()

            .ok_or(error!("Letting[1].Domain is an empty object"))?;

        let mut symtab = scope.borrow_mut();

        let domain = parse_domain(domain.0, domain.1, &mut symtab)?;

        symtab

            .insert(DeclarationPtr::new_domain_letting(name.clone(), domain))

            .ok_or(Error::Parse(format!(

                "Could not add {name} to symbol table as it already exists"

            )))

}

fn parse_domain(

    domain_name: &str,

    domain_value: &JsonValue,

    symbols: &mut SymbolTable,

) -> Result<DomainPtr> {

    match domain_name {

        "DomainInt" => Ok(parse_int_domain(domain_value, symbols)?),

        "DomainBool" => Ok(Domain::bool()),

        "DomainReference" => {

            let name = Name::user(

                domain_value

                    .as_array()

                    .ok_or(error!("DomainReference is not an array"))?[0]

                    .as_object()

                    .ok_or(error!("DomainReference[0] is not an object"))?["Name"]

                    .as_str()

                    .ok_or(error!("DomainReference[0].Name is not a string"))?,

            let ptr = symbols

                .lookup(&name)

                .ok_or(error!(format!("Name {name} not found")))?;

            let dom =

                Domain::reference(ptr).ok_or(error!("Could not construct reference domain"))?;

            Ok(dom)

        "DomainSet" => {

            let dom = domain_value.get(2).and_then(|v| v.as_object());

            let domain_obj = dom.expect("domain object exists");

            let domain = domain_obj

                .iter()

                .next()

                .ok_or(Error::Parse("DomainSet is an empty object".to_owned()))?;

            let domain = parse_domain(domain.0.as_str(), domain.1, symbols)?;

            let size = domain_value

                .get(1)

                .and_then(|v| v.as_object())

                .ok_or(error!("Set size attributes is not an object"))?;

            let size = parse_size_attr(size, symbols)?;

            let attr: SetAttr<IntVal> = SetAttr { size };

            Ok(Domain::set(attr, domain))

        "DomainMatrix" => {

            let domain_value = domain_value

                .as_array()

                .ok_or(error!("Domain matrix is not an array"))?;

            let indexed_by_domain = domain_value[0].clone();

            let (index_domain_name, index_domain_value) = indexed_by_domain

                .as_object()

                .ok_or(error!("DomainMatrix[0] is not an object"))?

                .iter()

                .next()

                .ok_or(error!(""))?;

            let (value_domain_name, value_domain_value) = domain_value[1]

                .as_object()

                .ok_or(error!(""))?

                .iter()

                .next()

                .ok_or(error!(""))?;

            let mut index_domains: Vec<DomainPtr> = vec![];

            index_domains.push(parse_domain(

                index_domain_name,

                index_domain_value,

                symbols,

            )?);

            let mut value_domain = parse_domain(value_domain_name, value_domain_value, symbols)?;

            while let Some((new_value_domain, mut indices)) = value_domain.as_matrix() {

                index_domains.append(&mut indices);

                value_domain = new_value_domain.clone()

            Ok(Domain::matrix(value_domain, index_domains))

        "DomainTuple" => {

            let domain_value = domain_value

                .as_array()

                .ok_or(error!("Domain tuple is not an array"))?;

            let domain = domain_value

                .iter()

                .map(|x| {

                    let domain = x

                        .as_object()

                        .ok_or(error!("DomainTuple[0] is not an object"))?

                        .iter()

                        .next()

                        .ok_or(error!("DomainTuple[0] is an empty object"))?;

                    parse_domain(domain.0, domain.1, symbols)

                })

                .collect::<Result<Vec<DomainPtr>>>()?;

            Ok(Domain::tuple(domain))

        "DomainRecord" => {

            let domain_value = domain_value

                .as_array()

                .ok_or(error!("Domain Record is not a json array"))?;

            let mut record_entries = vec![];

            for item in domain_value {

                let name = item[0]

                    .as_object()

                    .ok_or(error!("FindOrGiven[1] is not an object"))?["Name"]

                    .as_str()

                    .ok_or(error!("FindOrGiven[1].Name is not a string"))?;

                let name = Name::User(Ustr::from(name));

                let domain = item[1]

                    .as_object()

                    .ok_or(error!("FindOrGiven[2] is not an object"))?

                    .iter()

                    .next()

                    .ok_or(error!("FindOrGiven[2] is an empty object"))?;

                let domain = parse_domain(domain.0, domain.1, symbols)?;

                let rec = RecordEntry { name, domain };

                record_entries.push(rec);

            record_entries

                .iter()

                .cloned()

                .map(DeclarationPtr::new_record_field)

                .for_each(|decl| {

                    symbols

                        .insert(decl)

                        .expect("record field to not already be in the symbol table")

                });

            Ok(Domain::record(record_entries))

        "DomainFunction" => {

            let domain = domain_value

                .get(2)

                .and_then(|v| v.as_object())

                .ok_or(error!("Function domain is not an object"))?;

            let domain = domain

                .iter()

                .next()

                .ok_or(Error::Parse("DomainSet is an empty object".to_owned()))?;

            let domain = parse_domain(domain.0.as_str(), domain.1, symbols)?;

            let codomain = domain_value

                .get(3)

                .and_then(|v| v.as_object())

                .ok_or(error!("Function codomain is not an object"))?;

            let codomain = codomain

                .iter()

                .next()

                .ok_or(Error::Parse("DomainSet is an empty object".to_owned()))?;

            let codomain = parse_domain(codomain.0.as_str(), codomain.1, symbols)?;

            let attributes = domain_value

                .get(1)

                .and_then(|v| v.as_array())

                .ok_or(error!("Function attributes is not a json array"))?;

            let size = attributes

                .first()

                .and_then(|v| v.as_object())

                .ok_or(error!("Function size attributes is not an object"))?;

            let size = parse_size_attr(size, symbols)?;

            let partiality = attributes

                .get(1)

                .and_then(|v| v.as_str())

                .ok_or(error!("Function partiality is not a string"))?;

            let partiality = match partiality {

                "PartialityAttr_Partial" => Some(PartialityAttr::Partial),

                "PartialityAttr_Total" => Some(PartialityAttr::Total),

                _ => None,

            if partiality.is_none() {

                return Err(Error::Parse("Partiality is an unknown type".to_owned()));

            }

            let partiality = partiality.unwrap();

            let jectivity = attributes

                .get(2)

                .and_then(|v| v.as_str())

                .ok_or(error!("Function jectivity is not a string"))?;

            let jectivity = match jectivity {

                "JectivityAttr_Injective" => Some(JectivityAttr::Injective),

                "JectivityAttr_Surjective" => Some(JectivityAttr::Surjective),

                "JectivityAttr_Bijective" => Some(JectivityAttr::Bijective),

                "JectivityAttr_None" => Some(JectivityAttr::None),

                _ => None,

            if jectivity.is_none() {

                return Err(Error::Parse("Jectivity is an unknown type".to_owned()));

            }

            let jectivity = jectivity.unwrap();

            let attr: FuncAttr<IntVal> = FuncAttr {

                size,

                partiality,

                jectivity,

            };

            Ok(Domain::function(attr, domain, codomain))

        _ => Err(Error::Parse(

        )),

}

fn parse_size_attr(

    attr_map: &JsonMap<String, JsonValue>,

    symbols: &mut SymbolTable,

) -> Result<Range<IntVal>> {

    let attr_obj = attr_map

        .iter()

        .next()

        .ok_or(Error::Parse("SizeAttr is an empty object".to_owned()))?;

    match attr_obj.0.as_str() {

        "SizeAttr_None" => Ok(Range::Unbounded),

        "SizeAttr_MinSize" => {

            let size_int = parse_domain_value_int(attr_obj.1, symbols)

                .ok_or(error!("Could not parse int domain constant"))?;

            Ok(Range::UnboundedR(size_int.into()))

        "SizeAttr_MaxSize" => {

            let size_int = parse_domain_value_int(attr_obj.1, symbols)

                .ok_or(error!("Could not parse int domain constant"))?;

            Ok(Range::UnboundedL(size_int.into()))

        "SizeAttr_MinMaxSize" => {

            let min_max = attr_obj

                .1

                .as_array()

                .ok_or(error!("SizeAttr MinMaxSize is not a json array"))?;

            let min = min_max

                .first()

                .ok_or(error!("SizeAttr Min is not present"))?;

            let min_int = parse_domain_value_int(min, symbols)

                .ok_or(error!("Could not parse int domain constant"))?;

            let max = min_max

                .get(1)

                .ok_or(error!("SizeAttr Max is not present"))?;

            let max_int = parse_domain_value_int(max, symbols)

                .ok_or(error!("Could not parse int domain constant"))?;

            Ok(Range::Bounded(min_int.into(), max_int.into()))

        "SizeAttr_Size" => {

            let size_int = parse_domain_value_int(attr_obj.1, symbols)

                .ok_or(error!("Could not parse int domain constant"))?;

            Ok(Range::Single(size_int.into()))

        _ => Err(Error::Parse("SizeAttr is an unknown type".to_owned())),

}

fn parse_int_domain(v: &JsonValue, symbols: &SymbolTable) -> Result<DomainPtr> {

    let mut ranges = Vec::new();

    let arr = v

        .as_array()

        .ok_or(error!("DomainInt is not an array".to_owned()))?[1]

        .as_array()

        .ok_or(error!("DomainInt[1] is not an array".to_owned()))?;

    for range in arr {

        let range = range

            .as_object()

            .ok_or(error!("DomainInt[1] contains a non-object"))?

            .iter()

            .next()

            .ok_or(error!("DomainInt[1] contains an empty object"))?;

        match range.0.as_str() {

            "RangeBounded" => {

                let arr = range

                    .1

                    .as_array()

                    .ok_or(error!("RangeBounded is not an array".to_owned()))?;

                let mut nums = Vec::new();

                for item in arr.iter() {

                    let num = parse_domain_value_int(item, symbols)

                        .ok_or(error!("Could not parse int domain constant"))?;

                    nums.push(num);

                ranges.push(Range::Bounded(nums[0], nums[1]));

            "RangeSingle" => {

                let num = parse_domain_value_int(range.1, symbols)

                    .ok_or(error!("Could not parse int domain constant"))?;

                ranges.push(Range::Single(num));

            _ => return throw_error!("DomainInt[1] contains an unknown object"),

    Ok(Domain::int(ranges))

}

fn parse_domain_value_int(obj: &JsonValue, symbols: &SymbolTable) -> Option<i32> {

    parser_trace!("trying to parse domain value: {}", obj);

    fn try_parse_positive_int(obj: &JsonValue) -> Option<i32> {

        parser_trace!(".. trying as a positive domain value: {}", obj);

        let leaf_node = obj

            .pointer("/Constant/ConstantInt/1")

            .or_else(|| obj.pointer("/ConstantInt/1"))?;

        match leaf_node.as_i64()?.try_into() {

            Ok(x) => {

                parser_trace!(".. success!");

                Some(x)

                println!("Could not convert integer constant to i32: {leaf_node:#?}");

                None

    }

    fn try_parse_negative_int(obj: &JsonValue) -> Option<i32> {

        parser_trace!(".. trying as a negative domain value: {}", obj);

        let inner_constant_node = obj.pointer("/Op/MkOpNegate")?;

        let inner_num = try_parse_positive_int(inner_constant_node)?;

        parser_trace!(".. success!");

        Some(-inner_num)

    }

    fn try_parse_reference(obj: &JsonValue, symbols: &SymbolTable) -> Option<i32> {

        parser_trace!(".. trying as a domain reference: {}", obj);

        let inner_name = obj.pointer("/Reference/0/Name")?.as_str()?;

        parser_trace!(

        let name = Name::User(Ustr::from(inner_name));

        let decl = symbols.lookup(&name)?;

        let DeclarationKind::ValueLetting(d) = &decl.kind() as &DeclarationKind else {

            parser_trace!(".. name exists but is not a value letting!");

            return None;

        let a = d.clone().into_literal()?;

        let Literal::Int(a) = a else {

            return None;

        Some(a)

    }

    try_parse_positive_int(obj)

        .or_else(|| try_parse_negative_int(obj))

        .or_else(|| try_parse_reference(obj, symbols))

}

pub fn parse_expression(obj: &JsonValue, scope: &Rc<RefCell<SymbolTable>>) -> Option<Expression> {

    let binary_operators: HashMap<&str, BinOp> = [

        (

            "MkOpIn",

            Box::new(Expression::In) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpUnion",

            Box::new(Expression::Union) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpIntersect",

            Box::new(Expression::Intersect) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpSupset",

            Box::new(Expression::Supset) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpSupsetEq",

            Box::new(Expression::SupsetEq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpSubset",

            Box::new(Expression::Subset) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpSubsetEq",

            Box::new(Expression::SubsetEq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpEq",

            Box::new(Expression::Eq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpNeq",

            Box::new(Expression::Neq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpGeq",

            Box::new(Expression::Geq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLeq",

            Box::new(Expression::Leq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpGt",

            Box::new(Expression::Gt) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLt",

            Box::new(Expression::Lt) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpGt",

            Box::new(Expression::Gt) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLt",

            Box::new(Expression::Lt) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLexLt",

            Box::new(Expression::LexLt) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLexGt",

            Box::new(Expression::LexGt) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLexLeq",

            Box::new(Expression::LexLeq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpLexGeq",

            Box::new(Expression::LexGeq) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpDiv",

            Box::new(Expression::UnsafeDiv) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpMod",

            Box::new(Expression::UnsafeMod) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpMinus",

            Box::new(Expression::Minus) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpImply",

            Box::new(Expression::Imply) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpIff",

            Box::new(Expression::Iff) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpPow",

            Box::new(Expression::UnsafePow) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpImage",

            Box::new(Expression::Image) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpImageSet",

            Box::new(Expression::ImageSet) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpPreImage",

            Box::new(Expression::PreImage) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpInverse",

            Box::new(Expression::Inverse) as Box<dyn Fn(_, _, _) -> _>,

        ),

        (

            "MkOpRestrict",

            Box::new(Expression::Restrict) as Box<dyn Fn(_, _, _) -> _>,

        ),

    ]

    .into_iter()

    .collect();

    let unary_operators: HashMap<&str, UnaryOp> = [

        (

            "MkOpNot",

            Box::new(Expression::Not) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpNegate",

            Box::new(Expression::Neg) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpTwoBars",

            Box::new(Expression::Abs) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpAnd",

            Box::new(Expression::And) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpSum",

            Box::new(Expression::Sum) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpProduct",

            Box::new(Expression::Product) as Box<dyn Fn(_, _) -> _>,

        ),

        ("MkOpOr", Box::new(Expression::Or) as Box<dyn Fn(_, _) -> _>),

        (

            "MkOpMin",

            Box::new(Expression::Min) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpMax",

            Box::new(Expression::Max) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpAllDiff",

            Box::new(Expression::AllDiff) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpToInt",

            Box::new(Expression::ToInt) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpDefined",

            Box::new(Expression::Defined) as Box<dyn Fn(_, _) -> _>,

        ),

        (

            "MkOpRange",

            Box::new(Expression::Range) as Box<dyn Fn(_, _) -> _>,

        ),

    ]

    .into_iter()

    .collect();

    let mut binary_operator_names = binary_operators.iter().map(|x| x.0);

    let mut unary_operator_names = unary_operators.iter().map(|x| x.0);

    match obj {

        Value::Object(op) if op.contains_key("Op") => match &op["Op"] {

            Value::Object(bin_op) if binary_operator_names.any(|key| bin_op.contains_key(*key)) => {

                Some(parse_bin_op(bin_op, binary_operators, scope).unwrap())

            Value::Object(un_op) if unary_operator_names.any(|key| un_op.contains_key(*key)) => {

                Some(parse_unary_op(un_op, unary_operators, scope).unwrap())

            Value::Object(op) if op.contains_key("MkOpFlatten") => parse_flatten_op(op, scope),

            Value::Object(op)

                if op.contains_key("MkOpIndexing") || op.contains_key("MkOpSlicing") =>

                parse_indexing_slicing_op(op, scope)

        Value::Object(comprehension) if comprehension.contains_key("Comprehension") => {

            Some(parse_comprehension(comprehension, Rc::clone(scope), None).unwrap())

        Value::Object(refe) if refe.contains_key("Reference") => {

            let name = refe["Reference"].as_array()?[0].as_object()?["Name"].as_str()?;

            let user_name = Name::User(Ustr::from(name));

            let declaration: DeclarationPtr = scope

                .borrow()

                .lookup(&user_name)

            Some(Expression::Atomic(

                Metadata::new(),

                Atom::Reference(crate::ast::Reference::new(declaration)),

            ))

        Value::Object(abslit) if abslit.contains_key("AbstractLiteral") => {

            if abslit["AbstractLiteral"]

                .as_object()?

                .contains_key("AbsLitSet")

                Some(parse_abs_lit(&abslit["AbstractLiteral"]["AbsLitSet"], scope).unwrap())

            } else if abslit["AbstractLiteral"]

                .as_object()?

                .contains_key("AbsLitFunction")

                Some(

                    parse_abs_function(&abslit["AbstractLiteral"]["AbsLitFunction"], scope)

                        .unwrap(),

                )

                Some(parse_abstract_matrix_as_expr(obj, scope).unwrap())

        Value::Object(constant) if constant.contains_key("Constant") => Some(

            parse_constant(constant, scope)

                .or_else(|| parse_abstract_matrix_as_expr(obj, scope))

                .unwrap(),

        Value::Object(constant) if constant.contains_key("ConstantAbstract") => {

            Some(parse_abstract_matrix_as_expr(obj, scope).unwrap())

        Value::Object(constant) if constant.contains_key("ConstantInt") => {

            Some(parse_constant(constant, scope).unwrap())

        Value::Object(constant) if constant.contains_key("ConstantBool") => {

            Some(parse_constant(constant, scope).unwrap())

        _ => None,

}

fn parse_abs_lit(abs_set: &Value, scope: &Rc<RefCell<SymbolTable>>) -> Option<Expression> {

    let values = abs_set.as_array()?; // Ensure it's an array

    let expressions = values

        .iter()

        .map(|values| parse_expression(values, scope))

        .map(|values| values.expect("invalid subexpression")) // Ensure valid expressions

        .collect::<Vec<Expression>>(); // Collect all expressions

    Some(Expression::AbstractLiteral(

        Metadata::new(),

        AbstractLiteral::Set(expressions),

    ))

}

fn parse_abs_tuple(abs_tuple: &Value, scope: &Rc<RefCell<SymbolTable>>) -> Option<Expression> {

    let values = abs_tuple.as_array()?; // Ensure it's an array

    let expressions = values

        .iter()

        .map(|values| parse_expression(values, scope))

        .map(|values| values.expect("invalid subexpression")) // Ensure valid expressions

        .collect::<Vec<Expression>>(); // Collect all expressions

    Some(Expression::AbstractLiteral(

        Metadata::new(),

        AbstractLiteral::Tuple(expressions),

    ))

}

fn parse_abs_record(abs_record: &Value, scope: &Rc<RefCell<SymbolTable>>) -> Option<Expression> {

    let entries = abs_record.as_array()?; // Ensure it's an array

    let mut rec = vec![];

    for entry in entries {

        let entry = entry.as_array()?;

        let name = entry[0].as_object()?["Name"].as_str()?;

        let value = parse_expression(&entry[1], scope)?;

        let name = Name::User(Ustr::from(name));

        let rec_entry = RecordValue {

            name: name.clone(),

            value,

        };

        rec.push(rec_entry);

    Some(Expression::AbstractLiteral(

        Metadata::new(),

        AbstractLiteral::Record(rec),

    ))

}

fn parse_abs_function(

    abs_function: &Value,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    let entries = abs_function.as_array()?;

    let mut assignments = vec![];

    for entry in entries {

        let entry = entry.as_array()?;

        let expression = entry

            .iter()

            .map(|values| parse_expression(values, scope))

            .map(|values| values.expect("invalid subexpression")) // Ensure valid expressions

            .collect::<Vec<Expression>>(); // Collect all expressions

        let domain_value = expression.first().expect("Invalid function domain");

        let codomain_value = expression.get(1).expect("Invalid function codomain");

        let tuple = (domain_value.clone(), codomain_value.clone());

        assignments.push(tuple);

    Some(Expression::AbstractLiteral(

        Metadata::new(),

        AbstractLiteral::Function(assignments),

    ))

}

fn parse_comprehension(

    comprehension: &serde_json::Map<String, Value>,

    scope: Rc<RefCell<SymbolTable>>,

    comprehension_kind: Option<ACOperatorKind>,

) -> Option<Expression> {

    let value = &comprehension["Comprehension"];

    let mut comprehension = ComprehensionBuilder::new(Rc::clone(&scope));

    let generator_symboltable = comprehension.generator_symboltable();

    let return_expr_symboltable = comprehension.return_expr_symboltable();

    let generators_and_guards = value.pointer("/1")?.as_array()?.iter();

    for value in generators_and_guards {

        let value = value.as_object()?;

        let (name, value) = value.iter().next()?;

        comprehension = match name.as_str() {

            "Generator" => {

                let name = value.pointer("/GenDomainNoRepr/0/Single/Name")?.as_str()?;

                let (domain_name, domain_value) = value

                    .pointer("/GenDomainNoRepr/1")?

                    .as_object()?

                    .iter()

                    .next()?;

                let domain = parse_domain(

                    domain_name,

                    domain_value,

                    &mut generator_symboltable.borrow_mut(),

                .ok()?;

                comprehension.generator(DeclarationPtr::new_var(

                    Name::User(Ustr::from(name)),

                    domain,

            "Condition" => comprehension.guard(parse_expression(value, &generator_symboltable)?),

            x => {

    let expr = parse_expression(value.pointer("/0")?, &return_expr_symboltable)?;

    Some(Expression::Comprehension(

        Metadata::new(),

        Moo::new(comprehension.with_return_value(expr, comprehension_kind)),

    ))

}

fn parse_bin_op(

    bin_op: &serde_json::Map<String, Value>,

    binary_operators: HashMap<&str, BinOp>,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    let (key, value) = bin_op.into_iter().next()?;

    let constructor = binary_operators.get(key.as_str())?;

    match &value {

        Value::Array(bin_op_args) if bin_op_args.len() == 2 => {

            let arg1 = parse_expression(&bin_op_args[0], scope)?;

            let arg2 = parse_expression(&bin_op_args[1], scope)?;

            Some(constructor(Metadata::new(), Moo::new(arg1), Moo::new(arg2)))

}

fn parse_indexing_slicing_op(

    op: &serde_json::Map<String, Value>,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    let (key, value) = op.into_iter().next()?;

    let mut indices: Vec<Option<Expression>> = vec![];

    let mut all_known = true;

    match key.as_str() {

        "MkOpIndexing" => {

            match &value {

                Value::Array(op_args) if op_args.len() == 2 => {

                    target = parse_expression(&op_args[0], scope).expect("expected an expression");

                    indices.push(Some(

                        parse_expression(&op_args[1], scope).expect("expected an expression"),

                    ));

                }

        "MkOpSlicing" => {

            all_known = false;

            match &value {

                Value::Array(op_args) if op_args.len() == 3 => {

                    target = parse_expression(&op_args[0], scope).expect("expected an expression");

                    indices.push(None);

                }

            return None;

        match &mut target {

            Expression::UnsafeIndex(_, new_target, new_indices) => {

                indices.extend(new_indices.iter().cloned().rev().map(Some));

                target = Moo::unwrap_or_clone(new_target.clone());

            }

            Expression::UnsafeSlice(_, new_target, new_indices) => {

                all_known = false;

                indices.extend(new_indices.iter().cloned().rev());

                target = Moo::unwrap_or_clone(new_target.clone());

            }

                break;

    indices.reverse();

    if all_known {

            Metadata::new(),

            Moo::new(target),

            indices.into_iter().map(|x| x.unwrap()).collect(),

        Some(Expression::UnsafeSlice(

            Metadata::new(),

            Moo::new(target),

            indices,

        ))

}

fn parse_flatten_op(

    op: &serde_json::Map<String, Value>,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    let args = op.get("MkOpFlatten")?.as_array()?;

    let n = parse_expression(&args[0], scope);

    let matrix = parse_expression(&args[1], scope)?;

    if let Some(n) = n {

        Some(Expression::Flatten(

            Metadata::new(),

            Some(Moo::new(n)),

            Moo::new(matrix),

        ))

        Some(Expression::Flatten(Metadata::new(), None, Moo::new(matrix)))

}

fn parse_unary_op(

    un_op: &serde_json::Map<String, Value>,

    unary_operators: HashMap<&str, UnaryOp>,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    let (key, value) = un_op.into_iter().next()?;

    let constructor = unary_operators.get(key.as_str())?;

    let arg = match value {

        Value::Object(comprehension) if comprehension.contains_key("Comprehension") => {

            let comprehension_kind = match key.as_str() {

                "MkOpOr" => Some(ACOperatorKind::Or),

                "MkOpAnd" => Some(ACOperatorKind::And),

                "MkOpSum" => Some(ACOperatorKind::Sum),

                "MkOpProduct" => Some(ACOperatorKind::Product),

                _ => None,

            Some(parse_comprehension(comprehension, Rc::clone(scope), comprehension_kind).unwrap())

        _ => parse_expression(value, scope),

    }?;

    Some(constructor(Metadata::new(), Moo::new(arg)))

}

fn parse_abstract_matrix_as_expr(

    value: &serde_json::Value,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    parser_trace!("trying to parse an abstract literal matrix");

    let (values, domain_name, domain_value) =

        if let Some(abs_lit_matrix) = value.pointer("/AbstractLiteral/AbsLitMatrix") {

            parser_trace!(".. found JSON pointer /AbstractLiteral/AbstractLitMatrix");

            let (domain_name, domain_value) =

                abs_lit_matrix.pointer("/0")?.as_object()?.iter().next()?;

            let values = abs_lit_matrix.pointer("/1")?;

            Some((values, domain_name, domain_value))

        else if let Some(const_abs_lit_matrix) =

            value.pointer("/Constant/ConstantAbstract/AbsLitMatrix")

            parser_trace!(".. found JSON pointer /Constant/ConstantAbstract/AbsLitMatrix");

            let (domain_name, domain_value) = const_abs_lit_matrix

                .pointer("/0")?

                .as_object()?

                .iter()

                .next()?;

            let values = const_abs_lit_matrix.pointer("/1")?;

            Some((values, domain_name, domain_value))

        } else if let Some(const_abs_lit_matrix) = value.pointer("/ConstantAbstract/AbsLitMatrix") {

            parser_trace!(".. found JSON pointer /ConstantAbstract/AbsLitMatrix");

            let (domain_name, domain_value) = const_abs_lit_matrix

                .pointer("/0")?

                .as_object()?

                .iter()

                .next()?;

            let values = const_abs_lit_matrix.pointer("/1")?;

            Some((values, domain_name, domain_value))

            None

        }?;

    parser_trace!(".. found in domain and values in JSON:");

    parser_trace!(".. .. index domain name {domain_name}");

    parser_trace!(".. .. values {value}");

    let args_parsed = values.as_array().map(|x| {

        x.iter()

            .map(|x| parse_expression(x, scope))

            .map(|x| x.expect("invalid subexpression"))

            .collect::<Vec<Expression>>()

    })?;

    if !args_parsed.is_empty() {

        parser_trace!(

            args_parsed[0]

        parser_trace!(".. successfully parsed empty values ",);

    let mut symbols = scope.borrow_mut();

    match parse_domain(domain_name, domain_value, &mut symbols) {

        Ok(domain) => {

            parser_trace!("... sucessfully parsed domain as {domain}");

            Some(into_matrix_expr![args_parsed;domain])

            parser_trace!("... failed to parse domain, creating a matrix without one.");

            Some(into_matrix_expr![args_parsed])

}

fn parse_constant(

    constant: &serde_json::Map<String, Value>,

    scope: &Rc<RefCell<SymbolTable>>,

) -> Option<Expression> {

    match &constant.get("Constant") {

        Some(Value::Object(int)) if int.contains_key("ConstantInt") => {

            let int_32: i32 = match int["ConstantInt"].as_array()?[1].as_i64()?.try_into() {

                Ok(x) => x,

                    println!(

                        int["ConstantInt"]

                    return None;

            Some(Expression::Atomic(

                Metadata::new(),

                Atom::Literal(Literal::Int(int_32)),

            ))

        Some(Value::Object(b)) if b.contains_key("ConstantBool") => {

            let b: bool = b["ConstantBool"].as_bool()?;

            Some(Expression::Atomic(

                Metadata::new(),

                Atom::Literal(Literal::Bool(b)),

            ))

        Some(Value::Object(int)) if int.contains_key("ConstantAbstract") => {

            if let Some(Value::Object(obj)) = int.get("ConstantAbstract") {

                if let Some(arr) = obj.get("AbsLitSet") {

                    return parse_abs_lit(arr, scope);

                } else if let Some(arr) = obj.get("AbsLitMatrix") {

                    return parse_abstract_matrix_as_expr(arr, scope);

                } else if let Some(arr) = obj.get("AbsLitTuple") {

                    return parse_abs_tuple(arr, scope);

                } else if let Some(arr) = obj.get("AbsLitRecord") {

                    return parse_abs_record(arr, scope);

                } else if let Some(arr) = obj.get("AbsLitFunction") {

                    return parse_abs_function(arr, scope);

                }

            }

            None

            let int_expr = constant

                .get("ConstantInt")

                .and_then(|x| x.as_array())

                .and_then(|x| x[1].as_i64())

                .and_then(|x| x.try_into().ok())

                .map(|x| Expression::Atomic(Metadata::new(), Atom::Literal(Literal::Int(x))));

            if let e @ Some(_) = int_expr {

                return e;

            }

            let bool_expr = constant

                .get("ConstantBool")

                .and_then(|x| x.as_bool())

                .map(|x| Expression::Atomic(Metadata::new(), Atom::Literal(Literal::Bool(x))));

            if let e @ Some(_) = bool_expr {

                return e;

            }

}