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move over constraint
This commit is contained in:
Folkert
parent
8d2e0a738c
commit
0eb98a4c59
11 changed files with 429 additions and 1417 deletions
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@ -1,175 +1,398 @@
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use crate::expected::{Expected, PExpected};
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use roc_collections::all::{MutSet, SendMap};
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use roc_module::{ident::TagName, symbol::Symbol};
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use roc_collections::soa::{Index, Slice};
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use roc_module::ident::TagName;
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use roc_module::symbol::Symbol;
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use roc_region::all::{Loc, Region};
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use roc_types::subs::Variable;
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use roc_types::types::{Category, PatternCategory, Type};
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use roc_types::{subs::Variable, types::VariableDetail};
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/// A presence constraint is an additive constraint that defines the lower bound
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/// of a type. For example, `Present(t1, IncludesTag(A, []))` means that the
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/// type `t1` must contain at least the tag `A`. The additive nature of these
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/// constraints makes them behaviorally different from unification-based constraints.
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#[derive(Debug, Clone, PartialEq)]
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pub enum PresenceConstraint {
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IncludesTag(TagName, Vec<Type>, Region, PatternCategory),
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IsOpen,
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Pattern(Region, PatternCategory, PExpected<Type>),
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#[derive(Debug)]
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pub struct Constraints {
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pub constraints: Vec<Constraint>,
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pub types: Vec<Type>,
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pub variables: Vec<Variable>,
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pub def_types: Vec<(Symbol, Loc<Index<Type>>)>,
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pub let_constraints: Vec<LetConstraint>,
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pub categories: Vec<Category>,
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pub pattern_categories: Vec<PatternCategory>,
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pub expectations: Vec<Expected<Type>>,
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pub pattern_expectations: Vec<PExpected<Type>>,
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pub includes_tags: Vec<IncludesTag>,
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}
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impl Default for Constraints {
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fn default() -> Self {
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Self::new()
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}
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}
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impl Constraints {
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pub fn new() -> Self {
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let constraints = Vec::new();
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let mut types = Vec::new();
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let variables = Vec::new();
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let def_types = Vec::new();
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let let_constraints = Vec::new();
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let mut categories = Vec::new();
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let pattern_categories = Vec::new();
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let expectations = Vec::new();
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let pattern_expectations = Vec::new();
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let includes_tags = Vec::new();
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types.push(Type::EmptyRec);
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types.push(Type::EmptyTagUnion);
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categories.push(Category::Record);
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Self {
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constraints,
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types,
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variables,
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def_types,
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let_constraints,
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categories,
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pattern_categories,
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expectations,
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pattern_expectations,
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includes_tags,
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}
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}
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pub const EMPTY_RECORD: Index<Type> = Index::new(0);
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pub const EMPTY_TAG_UNION: Index<Type> = Index::new(1);
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pub const CATEGORY_RECORD: Index<Category> = Index::new(0);
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#[inline(always)]
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pub fn push_type(&mut self, typ: Type) -> Index<Type> {
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match typ {
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Type::EmptyRec => Self::EMPTY_RECORD,
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Type::EmptyTagUnion => Self::EMPTY_TAG_UNION,
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other => Index::push_new(&mut self.types, other),
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}
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}
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#[inline(always)]
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pub fn push_expected_type(&mut self, expected: Expected<Type>) -> Index<Expected<Type>> {
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Index::push_new(&mut self.expectations, expected)
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}
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#[inline(always)]
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pub fn push_category(&mut self, category: Category) -> Index<Category> {
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match category {
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Category::Record => Self::CATEGORY_RECORD,
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other => Index::push_new(&mut self.categories, other),
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}
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}
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pub fn equal_types(
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&mut self,
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typ: Type,
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expected: Expected<Type>,
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category: Category,
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region: Region,
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) -> Constraint {
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let type_index = Index::push_new(&mut self.types, typ);
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let expected_index = Index::push_new(&mut self.expectations, expected);
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let category_index = Index::push_new(&mut self.categories, category);
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Constraint::Eq(type_index, expected_index, category_index, region)
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}
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pub fn equal_pattern_types(
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&mut self,
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typ: Type,
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expected: PExpected<Type>,
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category: PatternCategory,
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region: Region,
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) -> Constraint {
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let type_index = Index::push_new(&mut self.types, typ);
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let expected_index = Index::push_new(&mut self.pattern_expectations, expected);
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let category_index = Index::push_new(&mut self.pattern_categories, category);
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Constraint::Pattern(type_index, expected_index, category_index, region)
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}
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pub fn pattern_presence(
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&mut self,
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typ: Type,
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expected: PExpected<Type>,
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category: PatternCategory,
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region: Region,
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) -> Constraint {
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let type_index = Index::push_new(&mut self.types, typ);
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let expected_index = Index::push_new(&mut self.pattern_expectations, expected);
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let category_index = Index::push_new(&mut self.pattern_categories, category);
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Constraint::PatternPresence(type_index, expected_index, category_index, region)
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}
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pub fn is_open_type(&mut self, typ: Type) -> Constraint {
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let type_index = Index::push_new(&mut self.types, typ);
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Constraint::IsOpenType(type_index)
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}
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pub fn includes_tag<I>(
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&mut self,
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typ: Type,
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tag_name: TagName,
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types: I,
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category: PatternCategory,
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region: Region,
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) -> Constraint
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where
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I: IntoIterator<Item = Type>,
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{
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let type_index = Index::push_new(&mut self.types, typ);
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let category_index = Index::push_new(&mut self.pattern_categories, category);
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let types_slice = Slice::extend_new(&mut self.types, types);
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let includes_tag = IncludesTag {
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type_index,
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tag_name,
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types: types_slice,
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pattern_category: category_index,
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region,
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};
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let includes_tag_index = Index::push_new(&mut self.includes_tags, includes_tag);
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Constraint::IncludesTag(includes_tag_index)
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}
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fn variable_slice<I>(&mut self, it: I) -> Slice<Variable>
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where
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I: IntoIterator<Item = Variable>,
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{
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let start = self.variables.len();
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self.variables.extend(it);
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let length = self.variables.len() - start;
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Slice::new(start as _, length as _)
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}
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fn def_types_slice<I>(&mut self, it: I) -> Slice<(Symbol, Loc<Type>)>
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where
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I: IntoIterator<Item = (Symbol, Loc<Type>)>,
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{
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let start = self.def_types.len();
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for (symbol, loc_type) in it {
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let type_index = Index::new(self.types.len() as _);
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let Loc { region, value } = loc_type;
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self.types.push(value);
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self.def_types.push((symbol, Loc::at(region, type_index)));
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}
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let length = self.def_types.len() - start;
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Slice::new(start as _, length as _)
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}
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pub fn exists<I>(&mut self, flex_vars: I, defs_constraint: Constraint) -> Constraint
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where
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I: IntoIterator<Item = Variable>,
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{
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let defs_and_ret_constraint = Index::new(self.constraints.len() as _);
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self.constraints.push(defs_constraint);
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self.constraints.push(Constraint::True);
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let let_contraint = LetConstraint {
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rigid_vars: Slice::default(),
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flex_vars: self.variable_slice(flex_vars),
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def_types: Slice::default(),
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defs_and_ret_constraint,
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};
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let let_index = Index::new(self.let_constraints.len() as _);
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self.let_constraints.push(let_contraint);
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Constraint::Let(let_index)
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}
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pub fn exists_many<I, C>(&mut self, flex_vars: I, defs_constraint: C) -> Constraint
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where
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I: IntoIterator<Item = Variable>,
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C: IntoIterator<Item = Constraint>,
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C::IntoIter: ExactSizeIterator,
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{
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let defs_constraint = self.and_constraint(defs_constraint);
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let defs_and_ret_constraint = Index::new(self.constraints.len() as _);
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self.constraints.push(defs_constraint);
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self.constraints.push(Constraint::True);
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let let_contraint = LetConstraint {
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rigid_vars: Slice::default(),
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flex_vars: self.variable_slice(flex_vars),
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def_types: Slice::default(),
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defs_and_ret_constraint,
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};
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let let_index = Index::new(self.let_constraints.len() as _);
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self.let_constraints.push(let_contraint);
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Constraint::Let(let_index)
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}
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pub fn let_constraint<I1, I2, I3>(
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&mut self,
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rigid_vars: I1,
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flex_vars: I2,
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def_types: I3,
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defs_constraint: Constraint,
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ret_constraint: Constraint,
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) -> Constraint
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where
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I1: IntoIterator<Item = Variable>,
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I2: IntoIterator<Item = Variable>,
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I3: IntoIterator<Item = (Symbol, Loc<Type>)>,
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{
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let defs_and_ret_constraint = Index::new(self.constraints.len() as _);
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self.constraints.push(defs_constraint);
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self.constraints.push(ret_constraint);
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let let_contraint = LetConstraint {
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rigid_vars: self.variable_slice(rigid_vars),
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flex_vars: self.variable_slice(flex_vars),
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def_types: self.def_types_slice(def_types),
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defs_and_ret_constraint,
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};
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let let_index = Index::new(self.let_constraints.len() as _);
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self.let_constraints.push(let_contraint);
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Constraint::Let(let_index)
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}
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pub fn and_constraint<I>(&mut self, constraints: I) -> Constraint
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where
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I: IntoIterator<Item = Constraint>,
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I::IntoIter: ExactSizeIterator,
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{
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let mut it = constraints.into_iter();
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match it.len() {
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0 => Constraint::True,
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1 => it.next().unwrap(),
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_ => {
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let start = self.constraints.len() as u32;
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self.constraints.extend(it);
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let end = self.constraints.len() as u32;
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let slice = Slice::new(start, (end - start) as u16);
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Constraint::And(slice)
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}
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}
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}
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pub fn lookup(
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&mut self,
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symbol: Symbol,
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expected: Expected<Type>,
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region: Region,
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) -> Constraint {
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Constraint::Lookup(
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symbol,
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Index::push_new(&mut self.expectations, expected),
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region,
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)
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}
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pub fn contains_save_the_environment(&self, constraint: &Constraint) -> bool {
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match constraint {
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Constraint::Eq(..) => false,
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Constraint::Store(..) => false,
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Constraint::Lookup(..) => false,
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Constraint::Pattern(..) => false,
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Constraint::True => false,
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Constraint::SaveTheEnvironment => true,
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Constraint::Let(index) => {
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let let_constraint = &self.let_constraints[index.index()];
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let offset = let_constraint.defs_and_ret_constraint.index();
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let defs_constraint = &self.constraints[offset];
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let ret_constraint = &self.constraints[offset + 1];
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self.contains_save_the_environment(defs_constraint)
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|| self.contains_save_the_environment(ret_constraint)
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}
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Constraint::And(slice) => {
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let constraints = &self.constraints[slice.indices()];
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constraints
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.iter()
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.any(|c| self.contains_save_the_environment(c))
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}
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Constraint::IsOpenType(_) => false,
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Constraint::IncludesTag(_) => false,
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Constraint::PatternPresence(_, _, _, _) => false,
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}
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}
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pub fn store(
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&mut self,
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typ: Type,
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variable: Variable,
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filename: &'static str,
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line_number: u32,
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) -> Constraint {
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let type_index = Index::new(self.types.len() as _);
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self.types.push(typ);
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Constraint::Store(type_index, variable, filename, line_number)
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}
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}
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static_assertions::assert_eq_size!([u8; 4 * 8], Constraint);
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static_assertions::assert_eq_size!([u8; 3 * 8 + 4], LetConstraint);
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#[derive(Debug, Clone, PartialEq)]
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pub enum Constraint {
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Eq(Type, Expected<Type>, Category, Region),
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Store(Type, Variable, &'static str, u32),
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Lookup(Symbol, Expected<Type>, Region),
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Pattern(Region, PatternCategory, Type, PExpected<Type>),
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Eq(Index<Type>, Index<Expected<Type>>, Index<Category>, Region),
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Store(Index<Type>, Variable, &'static str, u32),
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Lookup(Symbol, Index<Expected<Type>>, Region),
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Pattern(
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Index<Type>,
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Index<PExpected<Type>>,
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Index<PatternCategory>,
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Region,
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),
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True, // Used for things that always unify, e.g. blanks and runtime errors
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SaveTheEnvironment,
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Let(Box<LetConstraint>),
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And(Vec<Constraint>),
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Present(Type, PresenceConstraint),
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Let(Index<LetConstraint>),
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And(Slice<Constraint>),
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/// Presence constraints
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IsOpenType(Index<Type>), // Theory; always applied to a variable? if yes the use that
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IncludesTag(Index<IncludesTag>),
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PatternPresence(
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Index<Type>,
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Index<PExpected<Type>>,
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Index<PatternCategory>,
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Region,
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),
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}
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#[derive(Debug, Clone, PartialEq)]
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pub struct LetConstraint {
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pub rigid_vars: Vec<Variable>,
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pub flex_vars: Vec<Variable>,
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pub def_types: SendMap<Symbol, Loc<Type>>,
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pub defs_constraint: Constraint,
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pub ret_constraint: Constraint,
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pub rigid_vars: Slice<Variable>,
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pub flex_vars: Slice<Variable>,
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pub def_types: Slice<(Symbol, Loc<Type>)>,
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pub defs_and_ret_constraint: Index<(Constraint, Constraint)>,
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}
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// VALIDATE
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#[derive(Default, Clone)]
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struct Declared {
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pub rigid_vars: MutSet<Variable>,
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pub flex_vars: MutSet<Variable>,
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}
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impl Constraint {
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pub fn validate(&self) -> bool {
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let mut unbound = Default::default();
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validate_help(self, &Declared::default(), &mut unbound);
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if !unbound.type_variables.is_empty() {
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panic!("found unbound type variables {:?}", &unbound.type_variables);
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}
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if !unbound.lambda_set_variables.is_empty() {
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panic!(
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"found unbound lambda set variables {:?}",
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&unbound.lambda_set_variables
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);
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}
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if !unbound.recursion_variables.is_empty() {
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panic!(
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"found unbound recursion variables {:?}",
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&unbound.recursion_variables
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);
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}
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true
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}
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pub fn contains_save_the_environment(&self) -> bool {
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match self {
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Constraint::Eq(_, _, _, _) => false,
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Constraint::Store(_, _, _, _) => false,
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Constraint::Lookup(_, _, _) => false,
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Constraint::Pattern(_, _, _, _) => false,
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Constraint::True => false,
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Constraint::SaveTheEnvironment => true,
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Constraint::Let(boxed) => {
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boxed.ret_constraint.contains_save_the_environment()
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|| boxed.defs_constraint.contains_save_the_environment()
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}
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Constraint::And(cs) => cs.iter().any(|c| c.contains_save_the_environment()),
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Constraint::Present(_, _) => false,
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}
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}
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}
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fn subtract(declared: &Declared, detail: &VariableDetail, accum: &mut VariableDetail) {
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for var in &detail.type_variables {
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if !(declared.rigid_vars.contains(var) || declared.flex_vars.contains(var)) {
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accum.type_variables.insert(*var);
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}
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}
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// lambda set variables are always flex
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for var in &detail.lambda_set_variables {
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if declared.rigid_vars.contains(var) {
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panic!("lambda set variable {:?} is declared as rigid", var);
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}
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if !declared.flex_vars.contains(var) {
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accum.lambda_set_variables.push(*var);
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}
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}
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// recursion vars should be always rigid
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for var in &detail.recursion_variables {
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if declared.flex_vars.contains(var) {
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panic!("recursion variable {:?} is declared as flex", var);
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}
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if !declared.rigid_vars.contains(var) {
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accum.recursion_variables.insert(*var);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn validate_help(constraint: &Constraint, declared: &Declared, accum: &mut VariableDetail) {
|
||||
use Constraint::*;
|
||||
|
||||
match constraint {
|
||||
True | SaveTheEnvironment | Lookup(_, _, _) => { /* nothing */ }
|
||||
Store(typ, var, _, _) => {
|
||||
subtract(declared, &typ.variables_detail(), accum);
|
||||
|
||||
if !declared.flex_vars.contains(var) {
|
||||
accum.type_variables.insert(*var);
|
||||
}
|
||||
}
|
||||
Constraint::Eq(typ, expected, _, _) => {
|
||||
subtract(declared, &typ.variables_detail(), accum);
|
||||
subtract(declared, &expected.get_type_ref().variables_detail(), accum);
|
||||
}
|
||||
Constraint::Pattern(_, _, typ, expected) => {
|
||||
subtract(declared, &typ.variables_detail(), accum);
|
||||
subtract(declared, &expected.get_type_ref().variables_detail(), accum);
|
||||
}
|
||||
Constraint::Let(letcon) => {
|
||||
let mut declared = declared.clone();
|
||||
declared
|
||||
.rigid_vars
|
||||
.extend(letcon.rigid_vars.iter().copied());
|
||||
declared.flex_vars.extend(letcon.flex_vars.iter().copied());
|
||||
|
||||
validate_help(&letcon.defs_constraint, &declared, accum);
|
||||
validate_help(&letcon.ret_constraint, &declared, accum);
|
||||
}
|
||||
Constraint::And(inner) => {
|
||||
for c in inner {
|
||||
validate_help(c, declared, accum);
|
||||
}
|
||||
}
|
||||
Constraint::Present(typ, constr) => {
|
||||
subtract(declared, &typ.variables_detail(), accum);
|
||||
match constr {
|
||||
PresenceConstraint::IncludesTag(_, tys, _, _) => {
|
||||
for ty in tys {
|
||||
subtract(declared, &ty.variables_detail(), accum);
|
||||
}
|
||||
}
|
||||
PresenceConstraint::IsOpen => {}
|
||||
PresenceConstraint::Pattern(_, _, expected) => {
|
||||
subtract(declared, &typ.variables_detail(), accum);
|
||||
subtract(declared, &expected.get_type_ref().variables_detail(), accum);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
#[derive(Debug, Clone, PartialEq)]
|
||||
pub struct IncludesTag {
|
||||
pub type_index: Index<Type>,
|
||||
pub tag_name: TagName,
|
||||
pub types: Slice<Type>,
|
||||
pub pattern_category: Index<PatternCategory>,
|
||||
pub region: Region,
|
||||
}
|
||||
|
|
|
|||
Loading…
Add table
Add a link
Reference in a new issue