luau/Analysis/include/Luau/ConstraintSolver.h
rblanckaert 55a026811a
Sync to upstream/release/530 (#517)
* Run clang-format
* Contains a preliminary implementation of deferred constraint resolution
* Reduce stack usage by some recursive functions
* Fix a bug when smartCloning a BoundTypeVar
* Remove some GC related flags from VM
2022-06-03 15:15:45 -07:00

107 lines
3.8 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#pragma once
#include "Luau/Error.h"
#include "Luau/Variant.h"
#include "Luau/ConstraintGraphBuilder.h"
#include "Luau/TypeVar.h"
#include <vector>
namespace Luau
{
// TypeId, TypePackId, or Constraint*. It is impossible to know which, but we
// never dereference this pointer.
using BlockedConstraintId = const void*;
struct ConstraintSolver
{
TypeArena* arena;
InternalErrorReporter iceReporter;
// The entire set of constraints that the solver is trying to resolve.
std::vector<const Constraint*> constraints;
Scope2* rootScope;
std::vector<TypeError> errors;
// This includes every constraint that has not been fully solved.
// A constraint can be both blocked and unsolved, for instance.
std::unordered_set<const Constraint*> unsolvedConstraints;
// A mapping of constraint pointer to how many things the constraint is
// blocked on. Can be empty or 0 for constraints that are not blocked on
// anything.
std::unordered_map<const Constraint*, size_t> blockedConstraints;
// A mapping of type/pack pointers to the constraints they block.
std::unordered_map<BlockedConstraintId, std::vector<const Constraint*>> blocked;
explicit ConstraintSolver(TypeArena* arena, Scope2* rootScope);
/**
* Attempts to dispatch all pending constraints and reach a type solution
* that satisfies all of the constraints, recording any errors that are
* encountered.
**/
void run();
bool done();
bool tryDispatch(const Constraint* c);
bool tryDispatch(const SubtypeConstraint& c);
bool tryDispatch(const PackSubtypeConstraint& c);
bool tryDispatch(const GeneralizationConstraint& c);
bool tryDispatch(const InstantiationConstraint& c, const Constraint* constraint);
/**
* Marks a constraint as being blocked on a type or type pack. The constraint
* solver will not attempt to dispatch blocked constraints until their
* dependencies have made progress.
* @param target the type or type pack pointer that the constraint is blocked on.
* @param constraint the constraint to block.
**/
void block_(BlockedConstraintId target, const Constraint* constraint);
void block(const Constraint* target, const Constraint* constraint);
void block(TypeId target, const Constraint* constraint);
void block(TypePackId target, const Constraint* constraint);
/**
* Informs the solver that progress has been made on a type or type pack. The
* solver will wake up all constraints that are blocked on the type or type pack,
* and will resume attempting to dispatch them.
* @param progressed the type or type pack pointer that has progressed.
**/
void unblock_(BlockedConstraintId progressed);
void unblock(const Constraint* progressed);
void unblock(TypeId progressed);
void unblock(TypePackId progressed);
/**
* Returns whether the constraint is blocked on anything.
* @param constraint the constraint to check.
*/
bool isBlocked(const Constraint* constraint);
void reportErrors(const std::vector<TypeError>& errors);
/**
* Creates a new Unifier and performs a single unification operation. Commits
* the result and reports errors if necessary.
* @param subType the sub-type to unify.
* @param superType the super-type to unify.
*/
void unify(TypeId subType, TypeId superType);
/**
* Creates a new Unifier and performs a single unification operation. Commits
* the result and reports errors if necessary.
* @param subPack the sub-type pack to unify.
* @param superPack the super-type pack to unify.
*/
void unify(TypePackId subPack, TypePackId superPack);
};
void dump(Scope2* rootScope, struct ToStringOptions& opts);
} // namespace Luau