Changeset - 4fcb5d4646a6
[Not reviewed]
0 2 0
MH - 3 years ago 2022-02-21 13:36:02
contact@maxhenger.nl
WIP: Refactoring to use TypeIDs and InferIndices
2 files changed with 235 insertions and 72 deletions:
0 comments (0 inline, 0 general)
src/collections/scoped_buffer.rs
Show inline comments
 
@@ -28,144 +28,170 @@ impl<T: Sized> ScopedBuffer<T> {
 
    pub(crate) fn with_capacity(capacity: usize) -> Self {
 
        Self {
 
            inner: Vec::with_capacity(capacity),
 
        }
 
    }
 

	
 
    pub(crate) fn start_section(&mut self) -> ScopedSection<T> {
 
        let start_size = self.inner.len() as u32;
 
        ScopedSection {
 
            inner: &mut self.inner,
 
            start_size,
 
            #[cfg(debug_assertions)] cur_size: start_size,
 
        }
 
    }
 
}
 

	
 
impl<T: Clone> ScopedBuffer<T> {
 
    pub(crate) fn start_section_initialized(&mut self, initialize_with: &[T]) -> ScopedSection<T> {
 
        let start_size = self.inner.len() as u32;
 
        let _data_size = initialize_with.len() as u32;
 
        self.inner.extend_from_slice(initialize_with);
 
        ScopedSection{
 
            inner: &mut self.inner,
 
            start_size,
 
            #[cfg(debug_assertions)] cur_size: start_size + _data_size,
 
        }
 
    }
 
}
 

	
 
#[cfg(debug_assertions)]
 
impl<T: Sized> Drop for ScopedBuffer<T> {
 
    fn drop(&mut self) {
 
        // Make sure that everyone cleaned up the buffer neatly
 
        debug_assert!(self.inner.is_empty(), "dropped non-empty scoped buffer");
 
    }
 
}
 

	
 
/// A section of the buffer. Keeps track of where we started the section. When
 
/// done with the section one must call `into_vec` or `forget` to remove the
 
/// section from the underlying buffer. This will also be done upon dropping the
 
/// ScopedSection in case errors are being handled.
 
pub(crate) struct ScopedSection<T: Sized> {
 
    inner: *mut Vec<T>,
 
    start_size: u32,
 
    #[cfg(debug_assertions)] cur_size: u32,
 
}
 

	
 
impl<T: Sized> ScopedSection<T> {
 
    /// Pushes value into section
 
    #[inline]
 
    pub(crate) fn push(&mut self, value: T) {
 
        self.check_length();
 
        let vec = unsafe{&mut *self.inner};
 
        hide!(debug_assert_eq!(
 
            vec.len(), self.cur_size as usize,
 
            "trying to push onto section, but size is larger than expected"
 
        ));
 
        vec.push(value);
 
        hide!(self.cur_size += 1);
 
    }
 

	
 
    #[inline]
 
    pub(crate) fn len(&self) -> usize {
 
        self.check_length();
 
        let vec = unsafe{&mut *self.inner};
 
        hide!(debug_assert_eq!(
 
            vec.len(), self.cur_size as usize,
 
            "trying to get section length, but size is larger than expected"
 
        ));
 
        return vec.len() - self.start_size as usize;
 
    }
 

	
 
    #[inline]
 
    #[allow(unused_mut)] // used in debug mode
 
    pub(crate) fn forget(mut self) {
 
        self.check_length();
 
        let vec = unsafe{&mut *self.inner};
 
        hide!({
 
            debug_assert_eq!(
 
                vec.len(), self.cur_size as usize,
 
                "trying to forget section, but size is larger than expected"
 
            );
 
            self.cur_size = self.start_size;
 
        });
 
        hide!(self.cur_size = self.start_size);
 
        vec.truncate(self.start_size as usize);
 
    }
 

	
 
    #[inline]
 
    #[allow(unused_mut)] // used in debug mode
 
    pub(crate) fn into_vec(mut self) -> Vec<T> {
 
        self.check_length();
 
        let vec = unsafe{&mut *self.inner};
 
        hide!(self.cur_size = self.start_size);
 
        let section = Vec::from_iter(vec.drain(self.start_size as usize..));
 
        section
 
    }
 

	
 
    #[inline]
 
    pub(crate) fn check_length(&self) {
 
        hide!({
 
            let vec = unsafe{&*self.inner};
 
            debug_assert_eq!(
 
                vec.len(), self.cur_size as usize,
 
                "trying to turn section into vec, but size is larger than expected"
 
            );
 
            self.cur_size = self.start_size;
 
        });
 
        let section = Vec::from_iter(vec.drain(self.start_size as usize..));
 
        section
 
                "incorrect use of ScopedSection: underlying storage vector has changed size"
 
            )
 
        })
 
    }
 
}
 

	
 
impl<T: Sized + PartialEq> ScopedSection<T> {
 
    #[inline]
 
    pub(crate) fn push_unique(&mut self, value: T) {
 
        self.check_length();
 
        let vec = unsafe{&mut *self.inner};
 
        for item in &vec[self.start_size as usize..] {
 
            if *item == value {
 
                // item already exists
 
                return;
 
            }
 
        }
 

	
 
        vec.push(value);
 
        hide!(self.cur_size += 1);
 
    }
 

	
 
    #[inline]
 
    pub(crate) fn contains(&self, value: &T) -> bool {
 
        self.check_length();
 
        let vec = unsafe{&*self.inner};
 
        for index in self.start_size..vec.len() {
 
            if vec[index] == value {
 
                return true;
 
            }
 
        }
 

	
 
        return false;
 
    }
 
}
 

	
 
impl<T: Copy> ScopedSection<T> {
 
    pub(crate) fn iter_copied(&self) -> ScopedIter<T> {
 
        return ScopedIter{
 
            inner: self.inner,
 
            cur_index: self.start_size,
 
            last_index: unsafe{ (*self.inner).len() as u32 },
 
        }
 
    }
 
}
 

	
 
impl<T> std::ops::Index<usize> for ScopedSection<T> {
 
    type Output = T;
 

	
 
    fn index(&self, index: usize) -> &Self::Output {
 
        let vec = unsafe{&*self.inner};
 
        return &vec[self.start_size as usize + index]
 
    }
 
}
 

	
 
impl<T> std::ops::IndexMut<usize> for ScopedSection<T> {
 
    fn index_mut(&mut self, index: usize) -> &mut Self::Output {
 
        let vec = unsafe{&mut *self.inner};
 
        return &mut vec[self.start_size as usize + index]
 
    }
 
}
 

	
 
#[cfg(debug_assertions)]
 
impl<T: Sized> Drop for ScopedSection<T> {
 
    fn drop(&mut self) {
 
        let vec = unsafe{&mut *self.inner};
 
        hide!(debug_assert_eq!(vec.len(), self.cur_size as usize));
 
        vec.truncate(self.start_size as usize);
 
    }
 
}
 

	
 
/// Small utility for iterating over a section of the buffer. Same conditions as
 
/// the buffer apply: each time we retrieve an element the buffer must have the
 
/// same size as the moment of creation.
 
pub(crate) struct ScopedIter<T: Copy> {
 
    inner: *mut Vec<T>,
 
    cur_index: u32,
 
    last_index: u32,
 
}
 

	
 
impl<T: Copy> Iterator for ScopedIter<T> {
src/protocol/parser/pass_typing.rs
Show inline comments
 
@@ -835,97 +835,97 @@ pub(crate) struct ResolveQueueElement {
 
}
 

	
 
pub(crate) type ResolveQueue = Vec<ResolveQueueElement>;
 

	
 
#[derive(Clone)]
 
struct InferenceNode {
 
    expr_type: InferenceType,       // result type from expression
 
    expr_id: ExpressionId,          // expression that is evaluated
 
    inference_rule: InferenceRule,
 
    parent_index: Option<InferNodeIndex>,
 
    field_or_monomorph_index: i32,    // index of field
 
    poly_data_index: PolyDataIndex,            // index of extra data needed for inference
 
    type_id: TypeId,                // when applicable indexes into type table
 
}
 

	
 
/// Inferencing rule to apply. Some of these are reasonably generic. Other ones
 
/// require so much custom logic that we'll not try to come up with an
 
/// abstraction.
 
enum InferenceRule {
 
    Noop,
 
    MonoTemplate(InferenceRuleTemplate),
 
    BiEqual(InferenceRuleBiEqual),
 
    TriEqualArgs(InferenceRuleTriEqualArgs),
 
    TriEqualAll(InferenceRuleTriEqualAll),
 
    Concatenate(InferenceRuleTwoArgs),
 
    IndexingExpr(InferenceRuleIndexingExpr),
 
    SlicingExpr(InferenceRuleSlicingExpr),
 
    SelectStructField(InferenceRuleSelectStructField),
 
    SelectTupleMember(InferenceRuleSelectTupleMember),
 
    LiteralStruct(InferenceRuleLiteralStruct),
 
    LiteralEnum(InferenceRuleLiteralEnum),
 
    LiteralUnion(InferenceRuleLiteralUnion),
 
    LiteralArray(InferenceRuleLiteralArray),
 
    LiteralTuple(InferenceRuleLiteralTuple),
 
    CastExpr(InferenceRuleCastExpr),
 
    CallExpr(InferenceRuleCallExpr),
 
    VariableExpr(InferenceRuleVariableExpr),
 
}
 

	
 
impl InferenceRule {
 
    union_cast_method_impl!(as_mono_template, InferenceRuleTemplate, InferenceRule::MonoTemplate);
 
    union_cast_method_impl!(as_bi_equal, InferenceRuleBiEqual, InferenceRule::BiEqual);
 
    union_cast_method_impl!(as_tri_equal_args, InferenceRuleTriEqualArgs, InferenceRule::TriEqualArgs);
 
    union_cast_method_impl!(as_tri_equal_all, InferenceRuleTriEqualAll, InferenceRule::TriEqualAll);
 
    union_cast_method_impl!(as_concatenate, InferenceRuleTwoArgs, InferenceRule::Concatenate);
 
    union_cast_method_impl!(as_indexing_expr, InferenceRuleIndexingExpr, InferenceRule::IndexingExpr);
 
    union_cast_method_impl!(as_slicing_expr, InferenceRuleSlicingExpr, InferenceRule::SlicingExpr);
 
    union_cast_method_impl!(as_select_struct_field, InferenceRuleSelectStructField, InferenceRule::SelectStructField);
 
    union_cast_method_impl!(as_select_union_member, InferenceRuleSelectTupleMember, InferenceRule::SelectTupleMember);
 
    union_cast_method_impl!(as_select_tuple_member, InferenceRuleSelectTupleMember, InferenceRule::SelectTupleMember);
 
}
 

	
 
struct InferenceRuleTemplate {
 
    template: &'static [InferenceTypePart],
 
    application: InferenceRuleTemplateApplication,
 
}
 

	
 
impl InferenceRuleTemplate {
 
    fn new_none() -> Self {
 
        return Self{
 
            template: &[],
 
            application: InferenceRuleTemplateApplication::None,
 
        };
 
    }
 

	
 
    fn new_forced(template: &'static [InferenceTypePart]) -> Self {
 
        return Self{
 
            template,
 
            application: InferenceRuleTemplateApplication::Forced,
 
        };
 
    }
 

	
 
    fn new_template(template: &'static [InferenceTypePart]) -> Self {
 
        return Self{
 
            template,
 
            application: InferenceRuleTemplateApplication::Template,
 
        }
 
    }
 
}
 

	
 
#[derive(Clone, Copy)]
 
enum InferenceRuleTemplateApplication {
 
    None, // do not apply template, silly, but saves some bytes
 
    Forced,
 
    Template,
 
}
 

	
 
/// Type equality applied to 'self' and the argument. An optional template will
 
/// be applied to 'self' first. Example: "bitwise not"
 
struct InferenceRuleBiEqual {
 
    template: InferenceRuleTemplate,
 
    argument_index: InferNodeIndex,
 
}
 

	
 
/// Type equality applied to two arguments. Template can be applied to 'self'
 
/// (generally forced, since this rule does not apply a type equality constraint
 
/// to 'self') and the two arguments. Example: "equality operator"
 
struct InferenceRuleTriEqualArgs {
 
@@ -981,185 +981,188 @@ struct InferenceRuleLiteralEnum {
 

	
 
struct InferenceRuleLiteralUnion {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleLiteralArray {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleLiteralTuple {
 
    element_indices: Vec<InferNodeIndex>
 
}
 

	
 
struct InferenceRuleCastExpr {
 
    subject_index: InferNodeIndex,
 
}
 

	
 
struct InferenceRuleCallExpr {
 
    argument_indices: Vec<InferNodeIndex>
 
}
 

	
 
/// Data associated with a variable expression: an expression that reads the
 
/// value from a variable.
 
struct InferenceRuleVariableExpr {
 
    variable_index: InferNodeIndex,
 
}
 

	
 
/// Data associated with a variable: keeping track of all the variable
 
/// expressions in which it is used.
 
struct InferenceRuleVariable {
 
    used_at_indices: Vec<InferNodeIndex>,
 
}
 

	
 
/// This particular visitor will recurse depth-first into the AST and ensures
 
/// that all expressions have the appropriate types.
 
pub(crate) struct PassTyping {
 
    // Current definition we're typechecking.
 
    reserved_type_id: TypeId,
 
    definition_type: DefinitionType,
 
    poly_vars: Vec<ConcreteType>,
 
    // Temporary variables during construction of inference rulesr
 
    parent_index: Option<InferNodeIndex>,
 
    // Buffers for iteration over various types
 
    var_buffer: ScopedBuffer<VariableId>,
 
    expr_buffer: ScopedBuffer<ExpressionId>,
 
    stmt_buffer: ScopedBuffer<StatementId>,
 
    bool_buffer: ScopedBuffer<bool>,
 
    index_buffer: ScopedBuffer<usize>,
 
    poly_progress_buffer: ScopedBuffer<u32>,
 
    // Mapping from parser type to inferred type. We attempt to continue to
 
    // specify these types until we're stuck or we've fully determined the type.
 
    var_types: HashMap<VariableId, VarData>,            // types of variables
 
    infer_nodes: Vec<InferenceNode>,                     // will be transferred to type table at end
 
    poly_data: Vec<PolyData>,       // data for polymorph inference
 
    // Keeping track of which expressions need to be reinferred because the
 
    // expressions they're linked to made progression on an associated type
 
    expr_queued: DequeSet<i32>,
 
}
 

	
 
/// Generic struct that is used to store inferred types associated with
 
/// polymorphic types.
 
struct PolyData {
 
    definition_id: DefinitionId, // the definition, only used for user feedback
 
    /// Inferred types of the polymorphic variables as they are written down
 
    /// at the type's definition.
 
    poly_vars: Vec<InferenceType>,
 
    /// Inferred types of associated types (e.g. struct fields, tuple members,
 
    /// function arguments). These types may depend on the polymorphic variables
 
    /// defined above.
 
    associated: Vec<InferenceType>,
 
    /// Inferred "returned" type (e.g. if a struct field is selected, then this
 
    /// contains the type of the selected field, for a function call it contains
 
    /// the return type). May depend on the polymorphic variables defined above.
 
    returned: InferenceType,
 
}
 

	
 
impl Default for PolyData {
 
    fn default() -> Self {
 
        Self {
 
            definition_id: DefinitionId::new_invalid(),
 
            poly_vars: Vec::new(),
 
            associated: Vec::new(),
 
            returned: InferenceType::default(),
 
        }
 
    }
 
}
 

	
 
#[derive(Clone, Copy)]
 
enum PolyDataTypeIndex {
 
    Associated(usize), // indexes into `PolyData.associated`
 
    Returned,
 
}
 

	
 
impl PolyData {
 
    fn get_type(&self, index: PolyDataTypeIndex) -> &InferenceType {
 
        match index {
 
            PolyDataTypeIndex::Associated(index) => return &self.associated[index],
 
            PolyDataTypeIndex::Returned => return &self.returned,
 
        }
 
    }
 

	
 
    fn get_type_mut(&mut self, index: PolyDataTypeIndex) -> &mut InferenceType {
 
        match index {
 
            PolyDataTypeIndex::Associated(index) => return &mut self.associated[index],
 
            PolyDataTypeIndex::Returned => return &mut self.returned,
 
        }
 
    }
 
}
 

	
 
struct VarData {
 
    /// Type of the variable
 
    var_type: InferenceType,
 
    /// VariableExpressions that use the variable
 
    used_at: Vec<ExpressionId>,
 
    /// For channel statements we link to the other variable such that when one
 
    /// channel's interior type is resolved, we can also resolve the other one.
 
    linked_var: Option<VariableId>,
 
}
 

	
 
impl VarData {
 
    fn new_channel(var_type: InferenceType, other_port: VariableId) -> Self {
 
        Self{ var_type, used_at: Vec::new(), linked_var: Some(other_port) }
 
    }
 
    fn new_local(var_type: InferenceType) -> Self {
 
        Self{ var_type, used_at: Vec::new(), linked_var: None }
 
    }
 
}
 

	
 
impl PassTyping {
 
    pub(crate) fn new() -> Self {
 
        PassTyping {
 
            reserved_type_id: TypeId::new_invalid(),
 
            definition_type: DefinitionType::Function(FunctionDefinitionId::new_invalid()),
 
            poly_vars: Vec::new(),
 
            parent_index: None,
 
            var_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            expr_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            stmt_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_LARGE),
 
            bool_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            poly_progress_buffer: ScopedBuffer::with_capacity(BUFFER_INIT_CAP_SMALL),
 
            var_types: HashMap::new(),
 
            infer_nodes: Vec::new(),
 
            poly_data: Vec::new(),
 
            expr_queued: DequeSet::new(),
 
        }
 
    }
 

	
 
    pub(crate) fn queue_module_definitions(ctx: &mut Ctx, queue: &mut ResolveQueue) {
 
        debug_assert_eq!(ctx.module().phase, ModuleCompilationPhase::ValidatedAndLinked);
 
        let root_id = ctx.module().root_id;
 
        let root = &ctx.heap.protocol_descriptions[root_id];
 
        for definition_id in &root.definitions {
 
            let definition = &ctx.heap[*definition_id];
 

	
 
            let first_concrete_part = match definition {
 
                Definition::Function(definition) => {
 
                    if definition.poly_vars.is_empty() {
 
                        Some(ConcreteTypePart::Function(*definition_id, 0))
 
                    } else {
 
                        None
 
                    }
 
                }
 
                Definition::Component(definition) => {
 
                    if definition.poly_vars.is_empty() {
 
                        Some(ConcreteTypePart::Component(*definition_id, 0))
 
                    } else {
 
                        None
 
                    }
 
                },
 
                Definition::Enum(_) | Definition::Struct(_) | Definition::Union(_) => None,
 
            };
 

	
 
            if let Some(first_concrete_part) = first_concrete_part {
 
                let concrete_type = ConcreteType{ parts: vec![first_concrete_part] };
 
                let type_id = ctx.types.reserve_procedure_monomorph_type_id(definition_id, concrete_type);
 
                queue.push(ResolveQueueElement{
 
                    root_id,
 
                    definition_id: *definition_id,
 
                    reserved_type_id: type_id,
 
                })
 
            }
 
        }
 
    }
 

	
 
    pub(crate) fn handle_module_definition(
 
        &mut self, ctx: &mut Ctx, queue: &mut ResolveQueue, element: ResolveQueueElement
 
    ) -> VisitorResult {
 
        self.reset();
 
@@ -2310,151 +2313,170 @@ impl PassTyping {
 

	
 
                    // Seek the field that is referenced by the select
 
                    // expression
 
                    let mut field_found = false;
 
                    for (field_index, field) in struct_definition.fields.iter().enumerate() {
 
                        if field.identifier.value == rule.selected_field.value {
 
                            // Found the field of interest
 
                            field_found = true;
 
                            let node = &mut self.infer_nodes[node_index];
 
                            node.field_or_monomorph_index = field_index as i32;
 
                            break;
 
                        }
 
                    }
 

	
 
                    if !field_found {
 
                        let struct_definition = ctx.heap[definition_id].as_struct();
 
                        return Err(ParseError::new_error_at_span(
 
                            &ctx.module().source, rule.selected_field.span, format!(
 
                                "this field does not exist on the struct '{}'",
 
                                ast_struct_def.identifier.value.as_str()
 
                            )
 
                        ));
 
                    }
 

	
 
                    // Insert the initial data needed to infer polymorphic
 
                    // fields
 
                    let extra_index = self.insert_initial_select_polymorph_data(ctx, node_index, definition_id);
 
                    let node = &mut self.infer_nodes[node_index];
 
                    node.poly_data_index = extra_index;
 
                },
 
                Ok(None) => {
 
                    // We don't know what to do yet, because we don't know the
 
                    // subject type yet.
 
                    return Ok(())
 
                },
 
                Err(()) => {
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, rule.selected_field.span, format!(
 
                            "Can only apply field access to structs, got a subject of type '{}'",
 
                            subject_type.display_name(&ctx.heap)
 
                        )
 
                    ));
 
                },
 
            }
 
        }
 

	
 
        // If here then the field index is known, hence we can start inferring
 
        // the type of the selected field
 
        let node = &self.infer_nodes[node_index];
 
        let poly_data = &mut self.poly_data[node.poly_data_index as usize];
 
        let mut poly_progress = HashSet::new(); // TODO: @Performance
 

	
 
        // Apply to struct's type
 
        let signature_type: *mut _ = &mut poly_data.associated[0];
 
        let subject_type: *mut _ = &mut self.infer_nodes[subject_expr_idx as usize].expr_type;
 
        let field_expr_id = self.infer_nodes[node_index].expr_id;
 
        let subject_expr_id = self.infer_nodes[subject_index].expr_id;
 
        let mut poly_progress_section = self.poly_progress_buffer.start_section();
 

	
 
        let (_, progress_subject) = Self::apply_equal2_signature_constraint(
 
            ctx, upcast_id, Some(subject_id), poly_data, &mut poly_progress,
 
            signature_type, 0, subject_type, 0
 
        let (_, progress_subject_1) = self.apply_polydata_equal2_constraint(
 
            ctx, node_index, subject_expr_id, "selected struct's",
 
            PolyDataTypeIndex::Associated(0), 0, subject_index, 0, &mut poly_progress_section
 
        )?;
 
        let (_, progress_field_1) = self.apply_polydata_equal2_constraint(
 
            ctx, node_index, field_expr_id, "selected field's",
 
            PolyDataTypeIndex::Returned, 0, node_index, 0, &mut poly_progress_section
 
        )?;
 

	
 
        if progress_subject {
 
            self.expr_queued.push_back(subject_expr_idx);
 
        }
 

	
 
        // Apply to field's type
 
        let signature_type: *mut _ = &mut poly_data.returned;
 
        let expr_type: *mut _ = &mut self.infer_nodes[expr_idx as usize].expr_type;
 
        // Maybe make progress on types due to inferred polymorphic variables
 
        let progress_subject_2 = self.apply_polydata_polyvar_constraint(
 
            ctx, node_index, PolyDataTypeIndex::Associated(0), subject_index, &poly_progress_section
 
        );
 
        let progress_field_2 = self.apply_polydata_polyvar_constraint(
 
            ctx, node_index, PolyDataTypeIndex::Returned, node_index, &poly_progress_section
 
        );
 

	
 
        let (_, progress_expr) = Self::apply_equal2_signature_constraint(
 
            ctx, upcast_id, None, poly_data, &mut poly_progress,
 
            signature_type, 0, expr_type, 0
 
         )?;
 
        if progress_subject_1 || progress_subject_2 { self.queue_node(subject_index); }
 
        if progress_field_1 || progress_field_2 { self.queue_node_parent(node_index); }
 

	
 
        if progress_expr {
 
            if let Some(parent_id) = ctx.heap[upcast_id].parent_expr_id() {
 
                let parent_idx = ctx.heap[parent_id].get_unique_id_in_definition();
 
                self.expr_queued.push_back(parent_idx);
 
            }
 
        }
 
        return Ok(())
 
    }
 

	
 
        // Reapply progress in polymorphic variables to struct's type
 
        let signature_type: *mut _ = &mut poly_data.associated[0];
 
        let subject_type: *mut _ = &mut self.infer_nodes[subject_expr_idx as usize].expr_type;
 
    fn progress_inference_rule_select_tuple_member(&mut self, ctx: &mut Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
 
        let node = &self.infer_nodes[node_index];
 
        let rule = node.inference_rule.as_select_tuple_member();
 
        let subject_index = rule.subject_index;
 
        let tuple_member_index = rule.selected_index;
 

	
 
        let progress_subject = Self::apply_equal2_polyvar_constraint(
 
            poly_data, &poly_progress, signature_type, subject_type
 
        );
 
        fn get_tuple_size_from_inference_type(inference_type: &InferenceType) -> Result<Option<u32>, ()> {
 
            for part in &inference_type.parts {
 
                if part.is_marker() { continue; }
 
                if !part.is_concrete() { break; }
 

	
 
        let signature_type: *mut _ = &mut poly_data.returned;
 
        let expr_type: *mut _ = &mut self.infer_nodes[expr_idx as usize].expr_type;
 
                if let InferenceTypePart::Tuple(size) = part {
 
                    return Ok(Some(*size));
 
                } else {
 
                    return Err(()); // not a tuple!
 
                }
 
            }
 

	
 
        let progress_expr = Self::apply_equal2_polyvar_constraint(
 
            poly_data, &poly_progress, signature_type, expr_type
 
        );
 
            return Ok(None);
 
        }
 

	
 
        (progress_subject, progress_expr)
 
        if node.field_or_monomorph_index < 0 {
 
            let subject_type = &self.infer_nodes[subject_index].expr_type;
 
            let tuple_size = get_tuple_size_from_inference_type(subject_type);
 
            let tuple_size = match tuple_size {
 
                Ok(Some(tuple_size)) => {
 
                    tuple_size
 
                },
 
                Ok(None) => {
 
                    // We can't infer anything yet
 
                    return Ok(())
 
                },
 
                Err(()) => {
 
                    let select_expr_span = ctx.heap[node.expr_id].full_span();
 
                    return Err(ParseError::new_error_at_span(
 
                        &ctx.module().source, select_expr_span, format!(
 
                            "tuple element select cannot be applied to a subject of type '{}'",
 
                            subject_type.display_name(&ctx.heap)
 
                        )
 
                    ));
 
                }
 
            };
 

	
 
        return Ok(())
 
    }
 

	
 
    fn progress_inference_rule_select_tuple_member(&mut self, ctx: &mut Ctx, node_index: InferNodeIndex) -> Result<(), ParseError> {
 
        }
 

	
 
        return Ok(())
 
    }
 

	
 
    fn progress_template(&mut self, ctx: &Ctx, node_index: InferNodeIndex, application: InferenceRuleTemplateApplication, template: &[InferenceTypePart]) -> Result<bool, ParseError> {
 
        use InferenceRuleTemplateApplication as TA;
 

	
 
        match application {
 
            TA::None => Ok(false),
 
            TA::Template => self.apply_template_constraint(ctx, node_index, template),
 
            TA::Forced => self.apply_forced_constraint(ctx, node_index, template),
 
        }
 
    }
 

	
 
    fn progress_expr(&mut self, ctx: &mut Ctx, idx: i32) -> Result<(), ParseError> {
 
        let id = self.infer_nodes[idx as usize].expr_id;
 
        match &ctx.heap[id] {
 
            Expression::Assignment(expr) => {
 
                let id = expr.this;
 
                self.progress_assignment_expr(ctx, id)
 
            },
 
            Expression::Binding(expr) => {
 
                let id = expr.this;
 
                self.progress_binding_expr(ctx, id)
 
            },
 
            Expression::Conditional(expr) => {
 
                let id = expr.this;
 
                self.progress_conditional_expr(ctx, id)
 
            },
 
            Expression::Binary(expr) => {
 
                let id = expr.this;
 
                self.progress_binary_expr(ctx, id)
 
            },
 
            Expression::Unary(expr) => {
 
                let id = expr.this;
 
                self.progress_unary_expr(ctx, id)
 
            },
 
            Expression::Indexing(expr) => {
 
                let id = expr.this;
 
                self.progress_indexing_expr(ctx, id)
 
            },
 
            Expression::Slicing(expr) => {
 
                let id = expr.this;
 
                self.progress_slicing_expr(ctx, id)
 
            },
 
            Expression::Select(expr) => {
 
                let id = expr.this;
 
                self.progress_select_expr(ctx, id)
 
            },
 
            Expression::Literal(expr) => {
 
@@ -3758,127 +3780,242 @@ impl PassTyping {
 
        let expr_type = &mut self.infer_nodes[node_index].expr_type;
 

	
 
        match InferenceType::infer_subtree_for_single_type(expr_type, 0, template, 0, true) {
 
            SingleInferenceResult::Modified => Ok(true),
 
            SingleInferenceResult::Unmodified => Ok(false),
 
            SingleInferenceResult::Incompatible => Err(
 
                self.construct_template_type_error(ctx, node_index, template)
 
            )
 
        }
 
    }
 

	
 
    /// Applies a type constraint that expects the two provided types to be
 
    /// equal. We attempt to make progress in inferring the types. If the call
 
    /// is successful then the composition of all types are made equal.
 
    /// The "parent" `expr_id` is provided to construct errors.
 
    fn apply_equal2_constraint(
 
        &mut self, ctx: &Ctx, node_index: InferNodeIndex,
 
        arg1_index: InferNodeIndex, arg1_start_idx: usize,
 
        arg2_index: InferNodeIndex, arg2_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        let arg1_type: *mut _ = &mut self.infer_nodes[arg1_index].expr_type;
 
        let arg2_type: *mut _ = &mut self.infer_nodes[arg2_index].expr_type;
 

	
 
        let infer_res = unsafe{ InferenceType::infer_subtrees_for_both_types(
 
            arg1_type, arg1_start_idx,
 
            arg2_type, arg2_start_idx
 
        ) };
 
        if infer_res == DualInferenceResult::Incompatible {
 
            return Err(self.construct_arg_type_error(ctx, node_index, arg1_index, arg2_index));
 
        }
 

	
 
        Ok((infer_res.modified_lhs(), infer_res.modified_rhs()))
 
    }
 

	
 
    /// Applies an equal2 constraint between a member of the `PolyData` struct,
 
    /// and another inferred type. If any progress is made in the `PolyData`
 
    /// struct then the affected polymorphic variables are updated as well.
 
    ///
 
    /// Because a lot of types/expressions are involved in polymorphic type
 
    /// inference, some explanation: "outer_node" refers to the main expression
 
    /// that is the root cause of type inference (e.g. a struct literal
 
    /// expression, or a tuple member select expression). Associated with that
 
    /// outer node is `PolyData`, so that is what the "poly_data" variables
 
    /// are referring to. We are applying equality between a "poly_data" type
 
    /// and an associated expression (not necessarily the "outer_node", e.g.
 
    /// the expression that constructs the value of a struct field). Hence the
 
    /// "associated" variables.
 
    ///
 
    /// Again a special case: the `associated_expr_id` is only used
 
    /// Finally, when an error occurs we'll first show the outer node's
 
    /// location. As info, the `error_location_expr_id` span is shown,
 
    /// indicating that the "`error_type_name` type has been resolved to
 
    /// `outer_node_type`, but this expression has been resolved to
 
    /// `associated_node_type`".
 
    fn apply_polydata_equal2_constraint(
 
        &mut self, ctx: &Ctx,
 
        outer_node_index: InferNodeIndex, error_location_expr_id: ExpressionId, error_location_name: &str
 
        poly_data_type: PolyDataTypeIndex, poly_data_start_index: usize,
 
        associated_node_index: InferNodeIndex, associated_node_start_index: usize
 
        outer_node_index: InferNodeIndex, error_location_expr_id: ExpressionId, error_type_name: &str,
 
        poly_data_type_index: PolyDataTypeIndex, poly_data_start_index: usize,
 
        associated_node_index: InferNodeIndex, associated_node_start_index: usize,
 
        poly_progress_section: &mut ScopedSection<u32>,
 
    ) -> Result<(bool, bool), ParseError> {
 
        let poly_index = self.infer_nodes[outer_node_index].poly_data_index;
 
        let poly_data_type: *mut _ = self.poly_data[poly_index].get_type_mut(poly_data_type);
 
        let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
 
        let poly_data_type = self.poly_data[poly_data_index].get_type_mut(poly_data_type_index);
 
        let associated_type: *mut _ = &mut self.infer_nodes[associated_node_index].expr_type;
 

	
 
        let inference_result = unsafe{
 
            // Safety: pointers originate from different vectors, so cannot
 
            // alias.
 
            let poly_data_type: *mut _ = poly_data_type;
 
            InferenceType::infer_subtrees_for_both_types(
 
                poly_data_type, poly_data_start_index,
 
                associated_type, associated_node_start_index
 
            )
 
        };
 

	
 
        let modified_poly_data = inference_result.modified_lhs();
 
        let modified_associated = inference_result.modified_rhs();
 
        if inference_result == DualInferenceResult::Incompatible {
 
            let outer_node_expr_id = self.infer_nodes[outer_node_index].expr_id;
 
            let outer_node_span = ctx.heap[outer_node_expr_id].full_span();
 
            let detailed_span = ctx.heap[error_location_expr_id].
 
            let detailed_span = ctx.heap[error_location_expr_id].full_span();
 

	
 
            let outer_node_type = poly_data_type.display_name(&ctx.heap);
 
            let associated_type = self.infer_nodes[associated_node_index].expr_type.display_name(&ctx.heap);
 

	
 
            let source = &ctx.module().source;
 
            return Err(ParseError::new_error_str_at_span(
 
                source, outer_node_span, "failed to resolve the types of this expression"
 
            ).with_info_str_at_span(
 
                source, detailed_span, &format!(
 
                    "because the {} type has been resolved to '{}', but this expression has been resolved to '{}'",
 
                    error_type_name, outer_node_type, associated_type
 
                )
 
            ));
 
        }
 

	
 
        if modified_poly_data {
 
            debug_assert!(poly_data_type.has_marker);
 

	
 
            // Go through markers for polymorphic variables and use the
 
            // (hopefully) more specific types to update their representation
 
            // in the PolyData struct
 
            for (poly_var_index, poly_var_section) in poly_data_type.marker_iter() {
 
                let poly_var_type = &mut self.poly_data[poly_data_index].poly_vars[poly_var_index as usize];
 
                match InferenceType::infer_subtree_for_single_type(poly_var_type, 0, poly_var_section, 0, false) {
 
                    SingleInferenceResult::Modified => {
 
                        poly_progress_section.push_unique(poly_var_index);
 
                    },
 
                    SingleInferenceResult::Unmodified => {
 
                        // nothing to do
 
                    },
 
                    SingleInferenceResult::Incompatible => {
 
                        return Err(Self::construct_poly_arg_error(
 
                            ctx, &self.poly_data[poly_data_index],
 
                            self.infer_nodes[outer_node_index].expr_id
 
                        ));
 
                    }
 
                }
 
            }
 
        }
 

	
 
        return Ok((modified_poly_data, modified_associated));
 
    }
 

	
 
    fn apply_polydata_polyvar_constraint() -> bool {
 
    /// After calling `apply_polydata_equal2_constraint` on several expressions
 
    /// that are associated with some kind of polymorphic expression, several of
 
    /// the polymorphic variables might have been inferred to more specific
 
    /// types than before.
 
    ///
 
    /// At this point one should call this function to apply the progress in
 
    /// these polymorphic variables back onto the types that are functions of
 
    /// these polymorphic variables.
 
    ///
 
    /// An example: a struct literal with a polymorphic variable `T` may have
 
    /// two fields `foo` and `bar` each with different types that are a function
 
    /// of the polymorhic variable `T`. If the expressions constructing the
 
    /// value for the field `foo` causes the type `T` to progress, then we can
 
    /// also progress the type of the expression that constructs `bar`.
 
    ///
 
    /// And so we have `outer_node_index` + `poly_data_type_index` pointing to
 
    /// the appropriate type in the `PolyData` struct. Which will be updated
 
    /// first using the polymorphic variables. If we happen to have updated that
 
    /// type, then we should also progress the associated expression, hence the
 
    /// `associated_node_index`.
 
    fn apply_polydata_polyvar_constraint(
 
        &mut self, ctx: &Ctx,
 
        outer_node_index: InferNodeIndex, poly_data_type_index: PolyDataTypeIndex,
 
        associated_node_index: InferNodeIndex, poly_progress_section: &ScopedSection<u32>
 
    ) -> bool {
 
        let poly_data_index = self.infer_nodes[outer_node_index].poly_data_index;
 
        let poly_data = &mut self.poly_data[poly_data_index];
 

	
 
        // safety: we're borrowing from two distinct fields, so should be fine
 
        let poly_data_type = poly_data.get_type_mut(poly_data_type_index);
 
        let mut last_start_index = 0;
 
        let mut modified_poly_type = false;
 

	
 
        while let Some((poly_var_index, poly_var_start_index)) = poly_data_type.find_marker(last_start_index) {
 
            let poly_var_end_index = InferenceType::find_subtree_end_idx(&poly_data_type.parts, poly_var_start_index);
 
            if poly_progress_section.contains(&poly_var_index) {
 
                // We have updated this polymorphic variable, so try updating it
 
                // in the PolyData type
 
                let modified_in_poly_data = match InferenceType::infer_subtree_for_single_type(
 
                    poly_data_type, poly_var_start_index, &poly_data.poly_vars[poly_var_index as usize].parts, 0, false
 
                ) {
 
                    SingleInferenceResult::Modified => true,
 
                    SingleInferenceResult::Unmodified => false,
 
                    SingleInferenceResult::Incompatible => {
 
                        // practically impossible: before calling this function we gather all the
 
                        // data on the polymorphic variables from the associated expressions. So if
 
                        // the polymorphic variables in those expressions were not mutually
 
                        // compatible, we must have encountered that error already.
 
                        unreachable!()
 
                    },
 
                };
 

	
 
                modified_poly_type = modified_poly_type || modified_in_poly_data;
 
            }
 

	
 
            last_start_index = poly_var_end_index;
 
        }
 

	
 
        if modified_poly_type {
 
            let associated_type = &mut self.infer_nodes[associated_node_index].expr_type;
 
            match InferenceType::infer_subtree_for_single_type(
 
                associated_type, 0, &poly_data_type.parts, 0, true
 
            ) {
 
                SingleInferenceResult::Modified => return true,
 
                SingleInferenceResult::Unmodified => return false,
 
                SingleInferenceResult::Incompatible => unreachable!(), // same as above
 
            }
 
        } else {
 
            // Did not update associated type
 
            return false;
 
        }
 
    }
 

	
 
    /// Applies an equal2 constraint between a signature type (e.g. a function
 
    /// argument or struct field) and an expression whose type should match that
 
    /// expression. If we make progress on the signature, then we try to see if
 
    /// any of the embedded polymorphic types can be progressed.
 
    ///
 
    /// `outer_expr_id` is the main expression we're progressing (e.g. a 
 
    /// function call), while `expr_id` is the embedded expression we're 
 
    /// matching against the signature. `expression_type` and 
 
    /// `expression_start_idx` belong to `expr_id`.
 
    fn apply_equal2_signature_constraint(
 
        ctx: &Ctx, outer_expr_id: ExpressionId, expr_id: Option<ExpressionId>,
 
        polymorph_data: &mut PolyData, polymorph_progress: &mut HashSet<u32>,
 
        signature_type: *mut InferenceType, signature_start_idx: usize,
 
        expression_type: *mut InferenceType, expression_start_idx: usize
 
    ) -> Result<(bool, bool), ParseError> {
 
        // Safety: all pointers distinct
 

	
 
        // Infer the signature and expression type
 
        let infer_res = unsafe { 
 
            InferenceType::infer_subtrees_for_both_types(
 
                signature_type, signature_start_idx,
 
                expression_type, expression_start_idx
 
            )
 
        };
 

	
 
        if infer_res == DualInferenceResult::Incompatible {
 
            // TODO: Check if I still need to use this
 
            let outer_span = ctx.heap[outer_expr_id].full_span();
 
            let (span_name, span) = match expr_id {
 
                Some(expr_id) => ("argument's", ctx.heap[expr_id].full_span()),
 
                None => ("type's", outer_span)
 
            };
 
            let (signature_display_type, expression_display_type) = unsafe { (
 
                (&*signature_type).display_name(&ctx.heap),
 
                (&*expression_type).display_name(&ctx.heap)
 
            ) };
 

	
 
            return Err(ParseError::new_error_str_at_span(
 
                &ctx.module().source, outer_span,
 
                "failed to fully resolve the types of this expression"
 
            ).with_info_at_span(
 
                &ctx.module().source, span, format!(
 
                    "because the {} signature has been resolved to '{}', but the expression has been resolved to '{}'",
 
                    span_name, signature_display_type, expression_display_type
 
                )
 
            ));
0 comments (0 inline, 0 general)