luau/Analysis/src/Autocomplete.cpp
aaron 0d2688844a
Sync to upstream/release/632 (#1307)
# What's Changed?

- Fix #1137 by appropriately retaining additional metadata from
definition files throughout the type system.
- Improve Frontend for LSPs by appropriately allowing the cancellation
of typechecking while running its destructor.

## New Solver

- Added support for the `rawget` type function.
- Reduced overall static memory usage of builtin type functions.
- Fixed a crash where visitors could mutate a union or intersection type
and fail to invalidate iteration over them in doing so.
- Revised autocomplete functionality to not rely on a separate run of
the type solver when using the new solver.
- Implemented a more relaxed semantic rule for casting.
- Fixed some smaller crashes in the new solver.

## Native Code Generation

- Add additional codegen specialization for `math.sign`
- Cleaned up a large number of outstanding fflags in the code.

### Internal Contributors

Co-authored-by: Aaron Weiss <aaronweiss@roblox.com>
Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: James McNellis <jmcnellis@roblox.com>
Co-authored-by: Jeremy Yoo <jyoo@roblox.com>
Co-authored-by: Vighnesh Vijay <vvijay@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>

---------

Co-authored-by: Alexander McCord <amccord@roblox.com>
Co-authored-by: Andy Friesen <afriesen@roblox.com>
Co-authored-by: Vighnesh <vvijay@roblox.com>
Co-authored-by: Aviral Goel <agoel@roblox.com>
Co-authored-by: David Cope <dcope@roblox.com>
Co-authored-by: Lily Brown <lbrown@roblox.com>
Co-authored-by: Vyacheslav Egorov <vegorov@roblox.com>
2024-06-28 17:34:49 -07:00

1854 lines
65 KiB
C++

// This file is part of the Luau programming language and is licensed under MIT License; see LICENSE.txt for details
#include "Luau/Autocomplete.h"
#include "Luau/AstQuery.h"
#include "Luau/BuiltinDefinitions.h"
#include "Luau/Frontend.h"
#include "Luau/ToString.h"
#include "Luau/Subtyping.h"
#include "Luau/TypeInfer.h"
#include "Luau/TypePack.h"
#include <algorithm>
#include <unordered_set>
#include <utility>
LUAU_FASTFLAG(DebugLuauDeferredConstraintResolution);
static const std::unordered_set<std::string> kStatementStartingKeywords = {
"while", "if", "local", "repeat", "function", "do", "for", "return", "break", "continue", "type", "export"};
namespace Luau
{
static bool alreadyHasParens(const std::vector<AstNode*>& nodes)
{
auto iter = nodes.rbegin();
while (iter != nodes.rend() &&
((*iter)->is<AstExprLocal>() || (*iter)->is<AstExprGlobal>() || (*iter)->is<AstExprIndexName>() || (*iter)->is<AstExprIndexExpr>()))
{
iter++;
}
if (iter == nodes.rend() || iter == nodes.rbegin())
{
return false;
}
if (AstExprCall* call = (*iter)->as<AstExprCall>())
{
return call->func == *(iter - 1);
}
return false;
}
static ParenthesesRecommendation getParenRecommendationForFunc(const FunctionType* func, const std::vector<AstNode*>& nodes)
{
if (alreadyHasParens(nodes))
{
return ParenthesesRecommendation::None;
}
auto idxExpr = nodes.back()->as<AstExprIndexName>();
bool hasImplicitSelf = idxExpr && idxExpr->op == ':';
auto [argTypes, argVariadicPack] = Luau::flatten(func->argTypes);
if (argVariadicPack.has_value() && isVariadic(*argVariadicPack))
return ParenthesesRecommendation::CursorInside;
bool noArgFunction = argTypes.empty() || (hasImplicitSelf && argTypes.size() == 1);
return noArgFunction ? ParenthesesRecommendation::CursorAfter : ParenthesesRecommendation::CursorInside;
}
static ParenthesesRecommendation getParenRecommendationForIntersect(const IntersectionType* intersect, const std::vector<AstNode*>& nodes)
{
ParenthesesRecommendation rec = ParenthesesRecommendation::None;
for (Luau::TypeId partId : intersect->parts)
{
if (auto partFunc = Luau::get<FunctionType>(partId))
{
rec = std::max(rec, getParenRecommendationForFunc(partFunc, nodes));
}
else
{
return ParenthesesRecommendation::None;
}
}
return rec;
}
static ParenthesesRecommendation getParenRecommendation(TypeId id, const std::vector<AstNode*>& nodes, TypeCorrectKind typeCorrect)
{
// If element is already type-correct, even a function should be inserted without parenthesis
if (typeCorrect == TypeCorrectKind::Correct)
return ParenthesesRecommendation::None;
id = Luau::follow(id);
if (auto func = get<FunctionType>(id))
{
return getParenRecommendationForFunc(func, nodes);
}
else if (auto intersect = get<IntersectionType>(id))
{
return getParenRecommendationForIntersect(intersect, nodes);
}
return ParenthesesRecommendation::None;
}
static std::optional<TypeId> findExpectedTypeAt(const Module& module, AstNode* node, Position position)
{
auto expr = node->asExpr();
if (!expr)
return std::nullopt;
// Extra care for first function call argument location
// When we don't have anything inside () yet, we also don't have an AST node to base our lookup
if (AstExprCall* exprCall = expr->as<AstExprCall>())
{
if (exprCall->args.size == 0 && exprCall->argLocation.contains(position))
{
auto it = module.astTypes.find(exprCall->func);
if (!it)
return std::nullopt;
const FunctionType* ftv = get<FunctionType>(follow(*it));
if (!ftv)
return std::nullopt;
auto [head, tail] = flatten(ftv->argTypes);
unsigned index = exprCall->self ? 1 : 0;
if (index < head.size())
return head[index];
return std::nullopt;
}
}
auto it = module.astExpectedTypes.find(expr);
if (!it)
return std::nullopt;
return *it;
}
static bool checkTypeMatch(TypeId subTy, TypeId superTy, NotNull<Scope> scope, TypeArena* typeArena, NotNull<BuiltinTypes> builtinTypes)
{
InternalErrorReporter iceReporter;
UnifierSharedState unifierState(&iceReporter);
Normalizer normalizer{typeArena, builtinTypes, NotNull{&unifierState}};
if (FFlag::DebugLuauDeferredConstraintResolution)
{
Subtyping subtyping{builtinTypes, NotNull{typeArena}, NotNull{&normalizer}, NotNull{&iceReporter}, scope};
return subtyping.isSubtype(subTy, superTy).isSubtype;
}
else
{
Unifier unifier(NotNull<Normalizer>{&normalizer}, scope, Location(), Variance::Covariant);
// Cost of normalization can be too high for autocomplete response time requirements
unifier.normalize = false;
unifier.checkInhabited = false;
return unifier.canUnify(subTy, superTy).empty();
}
}
static TypeCorrectKind checkTypeCorrectKind(
const Module& module, TypeArena* typeArena, NotNull<BuiltinTypes> builtinTypes, AstNode* node, Position position, TypeId ty)
{
ty = follow(ty);
LUAU_ASSERT(module.hasModuleScope());
NotNull<Scope> moduleScope{module.getModuleScope().get()};
auto typeAtPosition = findExpectedTypeAt(module, node, position);
if (!typeAtPosition)
return TypeCorrectKind::None;
TypeId expectedType = follow(*typeAtPosition);
auto checkFunctionType = [typeArena, builtinTypes, moduleScope, &expectedType](const FunctionType* ftv) {
if (std::optional<TypeId> firstRetTy = first(ftv->retTypes))
return checkTypeMatch(*firstRetTy, expectedType, moduleScope, typeArena, builtinTypes);
return false;
};
// We also want to suggest functions that return compatible result
if (const FunctionType* ftv = get<FunctionType>(ty); ftv && checkFunctionType(ftv))
{
return TypeCorrectKind::CorrectFunctionResult;
}
else if (const IntersectionType* itv = get<IntersectionType>(ty))
{
for (TypeId id : itv->parts)
{
if (const FunctionType* ftv = get<FunctionType>(id); ftv && checkFunctionType(ftv))
{
return TypeCorrectKind::CorrectFunctionResult;
}
}
}
return checkTypeMatch(ty, expectedType, moduleScope, typeArena, builtinTypes) ? TypeCorrectKind::Correct : TypeCorrectKind::None;
}
enum class PropIndexType
{
Point,
Colon,
Key,
};
static void autocompleteProps(const Module& module, TypeArena* typeArena, NotNull<BuiltinTypes> builtinTypes, TypeId rootTy, TypeId ty,
PropIndexType indexType, const std::vector<AstNode*>& nodes, AutocompleteEntryMap& result, std::unordered_set<TypeId>& seen,
std::optional<const ClassType*> containingClass = std::nullopt)
{
rootTy = follow(rootTy);
ty = follow(ty);
if (seen.count(ty))
return;
seen.insert(ty);
auto isWrongIndexer = [typeArena, builtinTypes, &module, rootTy, indexType](Luau::TypeId type) {
if (indexType == PropIndexType::Key)
return false;
bool calledWithSelf = indexType == PropIndexType::Colon;
auto isCompatibleCall = [typeArena, builtinTypes, &module, rootTy, calledWithSelf](const FunctionType* ftv) {
// Strong match with definition is a success
if (calledWithSelf == ftv->hasSelf)
return true;
// Calls on classes require strict match between how function is declared and how it's called
if (get<ClassType>(rootTy))
return false;
// When called with ':', but declared without 'self', it is invalid if a function has incompatible first argument or no arguments at all
// When called with '.', but declared with 'self', it is considered invalid if first argument is compatible
if (std::optional<TypeId> firstArgTy = first(ftv->argTypes))
{
if (checkTypeMatch(rootTy, *firstArgTy, NotNull{module.getModuleScope().get()}, typeArena, builtinTypes))
return calledWithSelf;
}
return !calledWithSelf;
};
if (const FunctionType* ftv = get<FunctionType>(type))
return !isCompatibleCall(ftv);
// For intersections, any part that is successful makes the whole call successful
if (const IntersectionType* itv = get<IntersectionType>(type))
{
for (auto subType : itv->parts)
{
if (const FunctionType* ftv = get<FunctionType>(Luau::follow(subType)))
{
if (isCompatibleCall(ftv))
return false;
}
}
}
return calledWithSelf;
};
auto fillProps = [&](const ClassType::Props& props) {
for (const auto& [name, prop] : props)
{
// We are walking up the class hierarchy, so if we encounter a property that we have
// already populated, it takes precedence over the property we found just now.
if (result.count(name) == 0 && name != kParseNameError)
{
Luau::TypeId type;
if (FFlag::DebugLuauDeferredConstraintResolution)
{
if (auto ty = prop.readTy)
type = follow(*ty);
else
continue;
}
else
type = follow(prop.type());
TypeCorrectKind typeCorrect = indexType == PropIndexType::Key
? TypeCorrectKind::Correct
: checkTypeCorrectKind(module, typeArena, builtinTypes, nodes.back(), {{}, {}}, type);
ParenthesesRecommendation parens =
indexType == PropIndexType::Key ? ParenthesesRecommendation::None : getParenRecommendation(type, nodes, typeCorrect);
result[name] = AutocompleteEntry{AutocompleteEntryKind::Property, type, prop.deprecated, isWrongIndexer(type), typeCorrect,
containingClass, &prop, prop.documentationSymbol, {}, parens, {}, indexType == PropIndexType::Colon};
}
}
};
auto fillMetatableProps = [&](const TableType* mtable) {
auto indexIt = mtable->props.find("__index");
if (indexIt != mtable->props.end())
{
TypeId followed = follow(indexIt->second.type());
if (get<TableType>(followed) || get<MetatableType>(followed))
{
autocompleteProps(module, typeArena, builtinTypes, rootTy, followed, indexType, nodes, result, seen);
}
else if (auto indexFunction = get<FunctionType>(followed))
{
std::optional<TypeId> indexFunctionResult = first(indexFunction->retTypes);
if (indexFunctionResult)
autocompleteProps(module, typeArena, builtinTypes, rootTy, *indexFunctionResult, indexType, nodes, result, seen);
}
}
};
if (auto cls = get<ClassType>(ty))
{
containingClass = containingClass.value_or(cls);
fillProps(cls->props);
if (cls->parent)
autocompleteProps(module, typeArena, builtinTypes, rootTy, *cls->parent, indexType, nodes, result, seen, containingClass);
}
else if (auto tbl = get<TableType>(ty))
fillProps(tbl->props);
else if (auto mt = get<MetatableType>(ty))
{
autocompleteProps(module, typeArena, builtinTypes, rootTy, mt->table, indexType, nodes, result, seen);
if (auto mtable = get<TableType>(follow(mt->metatable)))
fillMetatableProps(mtable);
}
else if (auto i = get<IntersectionType>(ty))
{
// Complete all properties in every variant
for (TypeId ty : i->parts)
{
AutocompleteEntryMap inner;
std::unordered_set<TypeId> innerSeen = seen;
autocompleteProps(module, typeArena, builtinTypes, rootTy, ty, indexType, nodes, inner, innerSeen);
for (auto& pair : inner)
result.insert(pair);
}
}
else if (auto u = get<UnionType>(ty))
{
// Complete all properties common to all variants
auto iter = begin(u);
auto endIter = end(u);
while (iter != endIter)
{
if (isNil(*iter))
++iter;
else
break;
}
if (iter == endIter)
return;
autocompleteProps(module, typeArena, builtinTypes, rootTy, *iter, indexType, nodes, result, seen);
++iter;
while (iter != endIter)
{
AutocompleteEntryMap inner;
std::unordered_set<TypeId> innerSeen;
if (isNil(*iter))
{
++iter;
continue;
}
autocompleteProps(module, typeArena, builtinTypes, rootTy, *iter, indexType, nodes, inner, innerSeen);
std::unordered_set<std::string> toRemove;
for (const auto& [k, v] : result)
{
(void)v;
if (!inner.count(k))
toRemove.insert(k);
}
for (const std::string& k : toRemove)
result.erase(k);
++iter;
}
}
else if (auto pt = get<PrimitiveType>(ty))
{
if (pt->metatable)
{
if (auto mtable = get<TableType>(*pt->metatable))
fillMetatableProps(mtable);
}
}
else if (get<StringSingleton>(get<SingletonType>(ty)))
{
autocompleteProps(module, typeArena, builtinTypes, rootTy, builtinTypes->stringType, indexType, nodes, result, seen);
}
}
static void autocompleteKeywords(
const SourceModule& sourceModule, const std::vector<AstNode*>& ancestry, Position position, AutocompleteEntryMap& result)
{
LUAU_ASSERT(!ancestry.empty());
AstNode* node = ancestry.back();
if (!node->is<AstExprFunction>() && node->asExpr())
{
// This is not strictly correct. We should recommend `and` and `or` only after
// another expression, not at the start of a new one. We should only recommend
// `not` at the start of an expression. Detecting either case reliably is quite
// complex, however; this is good enough for now.
// These are not context-sensitive keywords, so we can unconditionally assign.
result["and"] = {AutocompleteEntryKind::Keyword};
result["or"] = {AutocompleteEntryKind::Keyword};
result["not"] = {AutocompleteEntryKind::Keyword};
}
}
static void autocompleteProps(const Module& module, TypeArena* typeArena, NotNull<BuiltinTypes> builtinTypes, TypeId ty, PropIndexType indexType,
const std::vector<AstNode*>& nodes, AutocompleteEntryMap& result)
{
std::unordered_set<TypeId> seen;
autocompleteProps(module, typeArena, builtinTypes, ty, ty, indexType, nodes, result, seen);
}
AutocompleteEntryMap autocompleteProps(const Module& module, TypeArena* typeArena, NotNull<BuiltinTypes> builtinTypes, TypeId ty,
PropIndexType indexType, const std::vector<AstNode*>& nodes)
{
AutocompleteEntryMap result;
autocompleteProps(module, typeArena, builtinTypes, ty, indexType, nodes, result);
return result;
}
AutocompleteEntryMap autocompleteModuleTypes(const Module& module, Position position, std::string_view moduleName)
{
AutocompleteEntryMap result;
for (ScopePtr scope = findScopeAtPosition(module, position); scope; scope = scope->parent)
{
if (auto it = scope->importedTypeBindings.find(std::string(moduleName)); it != scope->importedTypeBindings.end())
{
for (const auto& [name, ty] : it->second)
result[name] = AutocompleteEntry{AutocompleteEntryKind::Type, ty.type};
break;
}
}
return result;
}
static void autocompleteStringSingleton(TypeId ty, bool addQuotes, AstNode* node, Position position, AutocompleteEntryMap& result)
{
if (position == node->location.begin || position == node->location.end)
{
if (auto str = node->as<AstExprConstantString>(); str && str->quoteStyle == AstExprConstantString::Quoted)
return;
else if (node->is<AstExprInterpString>())
return;
}
auto formatKey = [addQuotes](const std::string& key) {
if (addQuotes)
return "\"" + escape(key) + "\"";
return escape(key);
};
ty = follow(ty);
if (auto ss = get<StringSingleton>(get<SingletonType>(ty)))
{
result[formatKey(ss->value)] = AutocompleteEntry{AutocompleteEntryKind::String, ty, false, false, TypeCorrectKind::Correct};
}
else if (auto uty = get<UnionType>(ty))
{
for (auto el : uty)
{
if (auto ss = get<StringSingleton>(get<SingletonType>(el)))
result[formatKey(ss->value)] = AutocompleteEntry{AutocompleteEntryKind::String, ty, false, false, TypeCorrectKind::Correct};
}
}
};
static bool canSuggestInferredType(ScopePtr scope, TypeId ty)
{
ty = follow(ty);
// No point in suggesting 'any', invalid to suggest others
if (get<AnyType>(ty) || get<ErrorType>(ty) || get<GenericType>(ty) || get<FreeType>(ty))
return false;
// No syntax for unnamed tables with a metatable
if (get<MetatableType>(ty))
return false;
if (const TableType* ttv = get<TableType>(ty))
{
if (ttv->name)
return true;
if (ttv->syntheticName)
return false;
}
// We might still have a type with cycles or one that is too long, we'll check that later
return true;
}
// Walk complex type trees to find the element that is being edited
static std::optional<TypeId> findTypeElementAt(AstType* astType, TypeId ty, Position position);
static std::optional<TypeId> findTypeElementAt(const AstTypeList& astTypeList, TypePackId tp, Position position)
{
for (size_t i = 0; i < astTypeList.types.size; i++)
{
AstType* type = astTypeList.types.data[i];
if (type->location.containsClosed(position))
{
auto [head, _] = flatten(tp);
if (i < head.size())
return findTypeElementAt(type, head[i], position);
}
}
if (AstTypePack* argTp = astTypeList.tailType)
{
if (auto variadic = argTp->as<AstTypePackVariadic>())
{
if (variadic->location.containsClosed(position))
{
auto [_, tail] = flatten(tp);
if (tail)
{
if (const VariadicTypePack* vtp = get<VariadicTypePack>(follow(*tail)))
return findTypeElementAt(variadic->variadicType, vtp->ty, position);
}
}
}
}
return {};
}
static std::optional<TypeId> findTypeElementAt(AstType* astType, TypeId ty, Position position)
{
ty = follow(ty);
if (astType->is<AstTypeReference>())
return ty;
if (astType->is<AstTypeError>())
return ty;
if (AstTypeFunction* type = astType->as<AstTypeFunction>())
{
const FunctionType* ftv = get<FunctionType>(ty);
if (!ftv)
return {};
if (auto element = findTypeElementAt(type->argTypes, ftv->argTypes, position))
return element;
if (auto element = findTypeElementAt(type->returnTypes, ftv->retTypes, position))
return element;
}
// It's possible to walk through other types like intrsection and unions if we find value in doing that
return {};
}
std::optional<TypeId> getLocalTypeInScopeAt(const Module& module, Position position, AstLocal* local)
{
if (ScopePtr scope = findScopeAtPosition(module, position))
{
for (const auto& [name, binding] : scope->bindings)
{
if (name == local)
return binding.typeId;
}
}
return {};
}
template<typename T>
static std::optional<std::string> tryToStringDetailed(const ScopePtr& scope, T ty, bool functionTypeArguments)
{
ToStringOptions opts;
opts.useLineBreaks = false;
opts.hideTableKind = true;
opts.functionTypeArguments = functionTypeArguments;
opts.scope = scope;
ToStringResult name = toStringDetailed(ty, opts);
if (name.error || name.invalid || name.cycle || name.truncated)
return std::nullopt;
return name.name;
}
static std::optional<Name> tryGetTypeNameInScope(ScopePtr scope, TypeId ty, bool functionTypeArguments = false)
{
if (!canSuggestInferredType(scope, ty))
return std::nullopt;
return tryToStringDetailed(scope, ty, functionTypeArguments);
}
static bool tryAddTypeCorrectSuggestion(AutocompleteEntryMap& result, ScopePtr scope, AstType* topType, TypeId inferredType, Position position)
{
std::optional<TypeId> ty;
if (topType)
ty = findTypeElementAt(topType, inferredType, position);
else
ty = inferredType;
if (!ty)
return false;
if (auto name = tryGetTypeNameInScope(scope, *ty))
{
if (auto it = result.find(*name); it != result.end())
it->second.typeCorrect = TypeCorrectKind::Correct;
else
result[*name] = AutocompleteEntry{AutocompleteEntryKind::Type, *ty, false, false, TypeCorrectKind::Correct};
return true;
}
return false;
}
static std::optional<TypeId> tryGetTypePackTypeAt(TypePackId tp, size_t index)
{
auto [tpHead, tpTail] = flatten(tp);
if (index < tpHead.size())
return tpHead[index];
// Infinite tail
if (tpTail)
{
if (const VariadicTypePack* vtp = get<VariadicTypePack>(follow(*tpTail)))
return vtp->ty;
}
return {};
}
template<typename T>
std::optional<const T*> returnFirstNonnullOptionOfType(const UnionType* utv)
{
std::optional<const T*> ret;
for (TypeId subTy : utv)
{
if (isNil(subTy))
continue;
if (const T* ftv = get<T>(follow(subTy)))
{
if (ret.has_value())
{
return std::nullopt;
}
ret = ftv;
}
else
{
return std::nullopt;
}
}
return ret;
}
static std::optional<bool> functionIsExpectedAt(const Module& module, AstNode* node, Position position)
{
auto typeAtPosition = findExpectedTypeAt(module, node, position);
if (!typeAtPosition)
return std::nullopt;
TypeId expectedType = follow(*typeAtPosition);
if (get<FunctionType>(expectedType))
return true;
if (const IntersectionType* itv = get<IntersectionType>(expectedType))
{
return std::all_of(begin(itv->parts), end(itv->parts), [](auto&& ty) {
return get<FunctionType>(Luau::follow(ty)) != nullptr;
});
}
if (const UnionType* utv = get<UnionType>(expectedType))
return returnFirstNonnullOptionOfType<FunctionType>(utv).has_value();
return false;
}
AutocompleteEntryMap autocompleteTypeNames(const Module& module, Position position, const std::vector<AstNode*>& ancestry)
{
AutocompleteEntryMap result;
ScopePtr startScope = findScopeAtPosition(module, position);
for (ScopePtr scope = startScope; scope; scope = scope->parent)
{
for (const auto& [name, ty] : scope->exportedTypeBindings)
{
if (!result.count(name))
result[name] = AutocompleteEntry{AutocompleteEntryKind::Type, ty.type, false, false, TypeCorrectKind::None, std::nullopt,
std::nullopt, ty.type->documentationSymbol};
}
for (const auto& [name, ty] : scope->privateTypeBindings)
{
if (!result.count(name))
result[name] = AutocompleteEntry{AutocompleteEntryKind::Type, ty.type, false, false, TypeCorrectKind::None, std::nullopt,
std::nullopt, ty.type->documentationSymbol};
}
for (const auto& [name, _] : scope->importedTypeBindings)
{
if (auto binding = scope->linearSearchForBinding(name, true))
{
if (!result.count(name))
result[name] = AutocompleteEntry{AutocompleteEntryKind::Module, binding->typeId};
}
}
}
AstNode* parent = nullptr;
AstType* topType = nullptr; // TODO: rename?
for (auto it = ancestry.rbegin(), e = ancestry.rend(); it != e; ++it)
{
if (AstType* asType = (*it)->asType())
{
topType = asType;
}
else
{
parent = *it;
break;
}
}
if (!parent)
return result;
if (AstStatLocal* node = parent->as<AstStatLocal>()) // Try to provide inferred type of the local
{
// Look at which of the variable types we are defining
for (size_t i = 0; i < node->vars.size; i++)
{
AstLocal* var = node->vars.data[i];
if (var->annotation && var->annotation->location.containsClosed(position))
{
if (node->values.size == 0)
break;
unsigned tailPos = 0;
// For multiple return values we will try to unpack last function call return type pack
if (i >= node->values.size)
{
tailPos = int(i) - int(node->values.size) + 1;
i = int(node->values.size) - 1;
}
AstExpr* expr = node->values.data[i]->asExpr();
if (!expr)
break;
TypeId inferredType = nullptr;
if (AstExprCall* exprCall = expr->as<AstExprCall>())
{
if (auto it = module.astTypes.find(exprCall->func))
{
if (const FunctionType* ftv = get<FunctionType>(follow(*it)))
{
if (auto ty = tryGetTypePackTypeAt(ftv->retTypes, tailPos))
inferredType = *ty;
}
}
}
else
{
if (tailPos != 0)
break;
if (auto it = module.astTypes.find(expr))
inferredType = *it;
}
if (inferredType)
tryAddTypeCorrectSuggestion(result, startScope, topType, inferredType, position);
break;
}
}
}
else if (AstExprFunction* node = parent->as<AstExprFunction>())
{
// For lookup inside expected function type if that's available
auto tryGetExpectedFunctionType = [](const Module& module, AstExpr* expr) -> const FunctionType* {
auto it = module.astExpectedTypes.find(expr);
if (!it)
return nullptr;
TypeId ty = follow(*it);
if (const FunctionType* ftv = get<FunctionType>(ty))
return ftv;
// Handle optional function type
if (const UnionType* utv = get<UnionType>(ty))
{
return returnFirstNonnullOptionOfType<FunctionType>(utv).value_or(nullptr);
}
return nullptr;
};
// Find which argument type we are defining
for (size_t i = 0; i < node->args.size; i++)
{
AstLocal* arg = node->args.data[i];
if (arg->annotation && arg->annotation->location.containsClosed(position))
{
if (const FunctionType* ftv = tryGetExpectedFunctionType(module, node))
{
if (auto ty = tryGetTypePackTypeAt(ftv->argTypes, i))
tryAddTypeCorrectSuggestion(result, startScope, topType, *ty, position);
}
// Otherwise, try to use the type inferred by typechecker
else if (auto inferredType = getLocalTypeInScopeAt(module, position, arg))
{
tryAddTypeCorrectSuggestion(result, startScope, topType, *inferredType, position);
}
break;
}
}
if (AstTypePack* argTp = node->varargAnnotation)
{
if (auto variadic = argTp->as<AstTypePackVariadic>())
{
if (variadic->location.containsClosed(position))
{
if (const FunctionType* ftv = tryGetExpectedFunctionType(module, node))
{
if (auto ty = tryGetTypePackTypeAt(ftv->argTypes, ~0u))
tryAddTypeCorrectSuggestion(result, startScope, topType, *ty, position);
}
}
}
}
if (!node->returnAnnotation)
return result;
for (size_t i = 0; i < node->returnAnnotation->types.size; i++)
{
AstType* ret = node->returnAnnotation->types.data[i];
if (ret->location.containsClosed(position))
{
if (const FunctionType* ftv = tryGetExpectedFunctionType(module, node))
{
if (auto ty = tryGetTypePackTypeAt(ftv->retTypes, i))
tryAddTypeCorrectSuggestion(result, startScope, topType, *ty, position);
}
// TODO: with additional type information, we could suggest inferred return type here
break;
}
}
if (AstTypePack* retTp = node->returnAnnotation->tailType)
{
if (auto variadic = retTp->as<AstTypePackVariadic>())
{
if (variadic->location.containsClosed(position))
{
if (const FunctionType* ftv = tryGetExpectedFunctionType(module, node))
{
if (auto ty = tryGetTypePackTypeAt(ftv->retTypes, ~0u))
tryAddTypeCorrectSuggestion(result, startScope, topType, *ty, position);
}
}
}
}
}
return result;
}
static bool isInLocalNames(const std::vector<AstNode*>& ancestry, Position position)
{
for (auto iter = ancestry.rbegin(); iter != ancestry.rend(); iter++)
{
if (auto statLocal = (*iter)->as<AstStatLocal>())
{
for (auto var : statLocal->vars)
{
if (var->location.containsClosed(position))
{
return true;
}
}
}
else if (auto funcExpr = (*iter)->as<AstExprFunction>())
{
if (funcExpr->argLocation && funcExpr->argLocation->contains(position))
{
return true;
}
}
else if (auto localFunc = (*iter)->as<AstStatLocalFunction>())
{
return localFunc->name->location.containsClosed(position);
}
else if (auto block = (*iter)->as<AstStatBlock>())
{
if (block->body.size > 0)
{
return false;
}
}
else if ((*iter)->asStat())
{
return false;
}
}
return false;
}
static bool isIdentifier(AstNode* node)
{
return node->is<AstExprGlobal>() || node->is<AstExprLocal>();
}
static bool isBeingDefined(const std::vector<AstNode*>& ancestry, const Symbol& symbol)
{
// Current set of rules only check for local binding match
if (!symbol.local)
return false;
for (auto iter = ancestry.rbegin(); iter != ancestry.rend(); iter++)
{
if (auto statLocal = (*iter)->as<AstStatLocal>())
{
for (auto var : statLocal->vars)
{
if (symbol.local == var)
return true;
}
}
}
return false;
}
template<typename T>
T* extractStat(const std::vector<AstNode*>& ancestry)
{
AstNode* node = ancestry.size() >= 1 ? ancestry.rbegin()[0] : nullptr;
if (!node)
return nullptr;
if (T* t = node->as<T>())
return t;
AstNode* parent = ancestry.size() >= 2 ? ancestry.rbegin()[1] : nullptr;
if (!parent)
return nullptr;
AstNode* grandParent = ancestry.size() >= 3 ? ancestry.rbegin()[2] : nullptr;
AstNode* greatGrandParent = ancestry.size() >= 4 ? ancestry.rbegin()[3] : nullptr;
if (!grandParent)
return nullptr;
if (T* t = parent->as<T>(); t && grandParent->is<AstStatBlock>())
return t;
if (!greatGrandParent)
return nullptr;
if (T* t = greatGrandParent->as<T>(); t && grandParent->is<AstStatBlock>() && parent->is<AstStatError>() && isIdentifier(node))
return t;
return nullptr;
}
static bool isBindingLegalAtCurrentPosition(const Symbol& symbol, const Binding& binding, Position pos)
{
if (symbol.local)
return binding.location.end < pos;
// Builtin globals have an empty location; for defined globals, we want pos to be outside of the definition range to suggest it
return binding.location == Location() || !binding.location.containsClosed(pos);
}
static AutocompleteEntryMap autocompleteStatement(
const SourceModule& sourceModule, const Module& module, const std::vector<AstNode*>& ancestry, Position position)
{
// This is inefficient. :(
ScopePtr scope = findScopeAtPosition(module, position);
AutocompleteEntryMap result;
if (isInLocalNames(ancestry, position))
{
autocompleteKeywords(sourceModule, ancestry, position, result);
return result;
}
while (scope)
{
for (const auto& [name, binding] : scope->bindings)
{
if (!isBindingLegalAtCurrentPosition(name, binding, position))
continue;
std::string n = toString(name);
if (!result.count(n))
result[n] = {AutocompleteEntryKind::Binding, binding.typeId, binding.deprecated, false, TypeCorrectKind::None, std::nullopt,
std::nullopt, binding.documentationSymbol, {}, getParenRecommendation(binding.typeId, ancestry, TypeCorrectKind::None)};
}
scope = scope->parent;
}
for (const auto& kw : kStatementStartingKeywords)
result.emplace(kw, AutocompleteEntry{AutocompleteEntryKind::Keyword});
for (auto it = ancestry.rbegin(); it != ancestry.rend(); ++it)
{
if (AstStatForIn* statForIn = (*it)->as<AstStatForIn>(); statForIn && !statForIn->body->hasEnd)
result.emplace("end", AutocompleteEntry{AutocompleteEntryKind::Keyword});
else if (AstStatFor* statFor = (*it)->as<AstStatFor>(); statFor && !statFor->body->hasEnd)
result.emplace("end", AutocompleteEntry{AutocompleteEntryKind::Keyword});
else if (AstStatIf* statIf = (*it)->as<AstStatIf>())
{
bool hasEnd = statIf->thenbody->hasEnd;
if (statIf->elsebody)
{
if (AstStatBlock* elseBlock = statIf->elsebody->as<AstStatBlock>())
hasEnd = elseBlock->hasEnd;
}
if (!hasEnd)
result.emplace("end", AutocompleteEntry{AutocompleteEntryKind::Keyword});
}
else if (AstStatWhile* statWhile = (*it)->as<AstStatWhile>(); statWhile && !statWhile->body->hasEnd)
result.emplace("end", AutocompleteEntry{AutocompleteEntryKind::Keyword});
else if (AstExprFunction* exprFunction = (*it)->as<AstExprFunction>(); exprFunction && !exprFunction->body->hasEnd)
result.emplace("end", AutocompleteEntry{AutocompleteEntryKind::Keyword});
if (AstStatBlock* exprBlock = (*it)->as<AstStatBlock>(); exprBlock && !exprBlock->hasEnd)
result.emplace("end", AutocompleteEntry{AutocompleteEntryKind::Keyword});
}
if (ancestry.size() >= 2)
{
AstNode* parent = ancestry.rbegin()[1];
if (AstStatIf* statIf = parent->as<AstStatIf>())
{
if (!statIf->elsebody || (statIf->elseLocation && statIf->elseLocation->containsClosed(position)))
{
result.emplace("else", AutocompleteEntry{AutocompleteEntryKind::Keyword});
result.emplace("elseif", AutocompleteEntry{AutocompleteEntryKind::Keyword});
}
}
if (AstStatRepeat* statRepeat = parent->as<AstStatRepeat>(); statRepeat && !statRepeat->body->hasEnd)
result.emplace("until", AutocompleteEntry{AutocompleteEntryKind::Keyword});
}
if (ancestry.size() >= 4)
{
auto iter = ancestry.rbegin();
if (AstStatIf* statIf = iter[3]->as<AstStatIf>();
statIf != nullptr && !statIf->elsebody && iter[2]->is<AstStatBlock>() && iter[1]->is<AstStatError>() && isIdentifier(iter[0]))
{
result.emplace("else", AutocompleteEntry{AutocompleteEntryKind::Keyword});
result.emplace("elseif", AutocompleteEntry{AutocompleteEntryKind::Keyword});
}
}
if (AstStatRepeat* statRepeat = extractStat<AstStatRepeat>(ancestry); statRepeat && !statRepeat->body->hasEnd)
result.emplace("until", AutocompleteEntry{AutocompleteEntryKind::Keyword});
return result;
}
// Returns true iff `node` was handled by this function (completions, if any, are returned in `outResult`)
static bool autocompleteIfElseExpression(
const AstNode* node, const std::vector<AstNode*>& ancestry, const Position& position, AutocompleteEntryMap& outResult)
{
AstNode* parent = ancestry.size() >= 2 ? ancestry.rbegin()[1] : nullptr;
if (!parent)
return false;
if (node->is<AstExprIfElse>())
{
// Don't try to complete when the current node is an if-else expression (i.e. only try to complete when the node is a child of an if-else
// expression.
return true;
}
AstExprIfElse* ifElseExpr = parent->as<AstExprIfElse>();
if (!ifElseExpr || ifElseExpr->condition->location.containsClosed(position))
{
return false;
}
else if (!ifElseExpr->hasThen)
{
outResult["then"] = {AutocompleteEntryKind::Keyword};
return true;
}
else if (ifElseExpr->trueExpr->location.containsClosed(position))
{
return false;
}
else if (!ifElseExpr->hasElse)
{
outResult["else"] = {AutocompleteEntryKind::Keyword};
outResult["elseif"] = {AutocompleteEntryKind::Keyword};
return true;
}
else
{
return false;
}
}
static AutocompleteContext autocompleteExpression(const SourceModule& sourceModule, const Module& module, NotNull<BuiltinTypes> builtinTypes,
TypeArena* typeArena, const std::vector<AstNode*>& ancestry, Position position, AutocompleteEntryMap& result)
{
LUAU_ASSERT(!ancestry.empty());
AstNode* node = ancestry.rbegin()[0];
if (node->is<AstExprIndexName>())
{
if (auto it = module.astTypes.find(node->asExpr()))
autocompleteProps(module, typeArena, builtinTypes, *it, PropIndexType::Point, ancestry, result);
}
else if (autocompleteIfElseExpression(node, ancestry, position, result))
return AutocompleteContext::Keyword;
else if (node->is<AstExprFunction>())
return AutocompleteContext::Unknown;
else
{
// This is inefficient. :(
ScopePtr scope = findScopeAtPosition(module, position);
while (scope)
{
for (const auto& [name, binding] : scope->bindings)
{
if (!isBindingLegalAtCurrentPosition(name, binding, position))
continue;
if (isBeingDefined(ancestry, name))
continue;
std::string n = toString(name);
if (!result.count(n))
{
TypeCorrectKind typeCorrect = checkTypeCorrectKind(module, typeArena, builtinTypes, node, position, binding.typeId);
result[n] = {AutocompleteEntryKind::Binding, binding.typeId, binding.deprecated, false, typeCorrect, std::nullopt, std::nullopt,
binding.documentationSymbol, {}, getParenRecommendation(binding.typeId, ancestry, typeCorrect)};
}
}
scope = scope->parent;
}
TypeCorrectKind correctForNil = checkTypeCorrectKind(module, typeArena, builtinTypes, node, position, builtinTypes->nilType);
TypeCorrectKind correctForTrue = checkTypeCorrectKind(module, typeArena, builtinTypes, node, position, builtinTypes->trueType);
TypeCorrectKind correctForFalse = checkTypeCorrectKind(module, typeArena, builtinTypes, node, position, builtinTypes->falseType);
TypeCorrectKind correctForFunction =
functionIsExpectedAt(module, node, position).value_or(false) ? TypeCorrectKind::Correct : TypeCorrectKind::None;
result["if"] = {AutocompleteEntryKind::Keyword, std::nullopt, false, false};
result["true"] = {AutocompleteEntryKind::Keyword, builtinTypes->booleanType, false, false, correctForTrue};
result["false"] = {AutocompleteEntryKind::Keyword, builtinTypes->booleanType, false, false, correctForFalse};
result["nil"] = {AutocompleteEntryKind::Keyword, builtinTypes->nilType, false, false, correctForNil};
result["not"] = {AutocompleteEntryKind::Keyword};
result["function"] = {AutocompleteEntryKind::Keyword, std::nullopt, false, false, correctForFunction};
if (auto ty = findExpectedTypeAt(module, node, position))
autocompleteStringSingleton(*ty, true, node, position, result);
}
return AutocompleteContext::Expression;
}
static AutocompleteResult autocompleteExpression(const SourceModule& sourceModule, const Module& module, NotNull<BuiltinTypes> builtinTypes,
TypeArena* typeArena, const std::vector<AstNode*>& ancestry, Position position)
{
AutocompleteEntryMap result;
AutocompleteContext context = autocompleteExpression(sourceModule, module, builtinTypes, typeArena, ancestry, position, result);
return {result, ancestry, context};
}
static std::optional<const ClassType*> getMethodContainingClass(const ModulePtr& module, AstExpr* funcExpr)
{
AstExpr* parentExpr = nullptr;
if (auto indexName = funcExpr->as<AstExprIndexName>())
{
parentExpr = indexName->expr;
}
else if (auto indexExpr = funcExpr->as<AstExprIndexExpr>())
{
parentExpr = indexExpr->expr;
}
else
{
return std::nullopt;
}
auto parentIt = module->astTypes.find(parentExpr);
if (!parentIt)
{
return std::nullopt;
}
Luau::TypeId parentType = Luau::follow(*parentIt);
if (auto parentClass = Luau::get<ClassType>(parentType))
{
return parentClass;
}
if (auto parentUnion = Luau::get<UnionType>(parentType))
{
return returnFirstNonnullOptionOfType<ClassType>(parentUnion);
}
return std::nullopt;
}
static bool stringPartOfInterpString(const AstNode* node, Position position)
{
const AstExprInterpString* interpString = node->as<AstExprInterpString>();
if (!interpString)
{
return false;
}
for (const AstExpr* expression : interpString->expressions)
{
if (expression->location.containsClosed(position))
{
return false;
}
}
return true;
}
static bool isSimpleInterpolatedString(const AstNode* node)
{
const AstExprInterpString* interpString = node->as<AstExprInterpString>();
return interpString != nullptr && interpString->expressions.size == 0;
}
static std::optional<std::string> getStringContents(const AstNode* node)
{
if (const AstExprConstantString* string = node->as<AstExprConstantString>())
{
return std::string(string->value.data, string->value.size);
}
else if (const AstExprInterpString* interpString = node->as<AstExprInterpString>(); interpString && interpString->expressions.size == 0)
{
LUAU_ASSERT(interpString->strings.size == 1);
return std::string(interpString->strings.data->data, interpString->strings.data->size);
}
else
{
return std::nullopt;
}
}
static std::optional<AutocompleteEntryMap> autocompleteStringParams(const SourceModule& sourceModule, const ModulePtr& module,
const std::vector<AstNode*>& nodes, Position position, StringCompletionCallback callback)
{
if (nodes.size() < 2)
{
return std::nullopt;
}
if (!nodes.back()->is<AstExprConstantString>() && !isSimpleInterpolatedString(nodes.back()) && !nodes.back()->is<AstExprError>())
{
return std::nullopt;
}
if (!nodes.back()->is<AstExprError>())
{
if (nodes.back()->location.end == position || nodes.back()->location.begin == position)
{
return std::nullopt;
}
}
AstExprCall* candidate = nodes.at(nodes.size() - 2)->as<AstExprCall>();
if (!candidate)
{
return std::nullopt;
}
// HACK: All current instances of 'magic string' params are the first parameter of their functions,
// so we encode that here rather than putting a useless member on the FunctionType struct.
if (candidate->args.size > 1 && !candidate->args.data[0]->location.contains(position))
{
return std::nullopt;
}
auto it = module->astTypes.find(candidate->func);
if (!it)
{
return std::nullopt;
}
std::optional<std::string> candidateString = getStringContents(nodes.back());
auto performCallback = [&](const FunctionType* funcType) -> std::optional<AutocompleteEntryMap> {
for (const std::string& tag : funcType->tags)
{
if (std::optional<AutocompleteEntryMap> ret = callback(tag, getMethodContainingClass(module, candidate->func), candidateString))
{
return ret;
}
}
return std::nullopt;
};
auto followedId = Luau::follow(*it);
if (auto functionType = Luau::get<FunctionType>(followedId))
{
return performCallback(functionType);
}
if (auto intersect = Luau::get<IntersectionType>(followedId))
{
for (TypeId part : intersect->parts)
{
if (auto candidateFunctionType = Luau::get<FunctionType>(part))
{
if (std::optional<AutocompleteEntryMap> ret = performCallback(candidateFunctionType))
{
return ret;
}
}
}
}
return std::nullopt;
}
static AutocompleteResult autocompleteWhileLoopKeywords(std::vector<AstNode*> ancestry)
{
AutocompleteEntryMap ret;
ret["do"] = {AutocompleteEntryKind::Keyword};
ret["and"] = {AutocompleteEntryKind::Keyword};
ret["or"] = {AutocompleteEntryKind::Keyword};
return {std::move(ret), std::move(ancestry), AutocompleteContext::Keyword};
}
static std::string makeAnonymous(const ScopePtr& scope, const FunctionType& funcTy)
{
std::string result = "function(";
auto [args, tail] = Luau::flatten(funcTy.argTypes);
bool first = true;
// Skip the implicit 'self' argument if call is indexed with ':'
for (size_t argIdx = 0; argIdx < args.size(); ++argIdx)
{
if (!first)
result += ", ";
else
first = false;
std::string name;
if (argIdx < funcTy.argNames.size() && funcTy.argNames[argIdx])
name = funcTy.argNames[argIdx]->name;
else
name = "a" + std::to_string(argIdx);
if (std::optional<Name> type = tryGetTypeNameInScope(scope, args[argIdx], true))
result += name + ": " + *type;
else
result += name;
}
if (tail && (Luau::isVariadic(*tail) || Luau::get<Luau::FreeTypePack>(Luau::follow(*tail))))
{
if (!first)
result += ", ";
std::optional<std::string> varArgType;
if (const VariadicTypePack* pack = get<VariadicTypePack>(follow(*tail)))
{
if (std::optional<std::string> res = tryToStringDetailed(scope, pack->ty, true))
varArgType = std::move(res);
}
if (varArgType)
result += "...: " + *varArgType;
else
result += "...";
}
result += ")";
auto [rets, retTail] = Luau::flatten(funcTy.retTypes);
if (const size_t totalRetSize = rets.size() + (retTail ? 1 : 0); totalRetSize > 0)
{
if (std::optional<std::string> returnTypes = tryToStringDetailed(scope, funcTy.retTypes, true))
{
result += ": ";
bool wrap = totalRetSize != 1;
if (wrap)
result += "(";
result += *returnTypes;
if (wrap)
result += ")";
}
}
result += " end";
return result;
}
static std::optional<AutocompleteEntry> makeAnonymousAutofilled(
const ModulePtr& module, Position position, const AstNode* node, const std::vector<AstNode*>& ancestry)
{
const AstExprCall* call = node->as<AstExprCall>();
if (!call && ancestry.size() > 1)
call = ancestry[ancestry.size() - 2]->as<AstExprCall>();
if (!call)
return std::nullopt;
if (!call->location.containsClosed(position) || call->func->location.containsClosed(position))
return std::nullopt;
TypeId* typeIter = module->astTypes.find(call->func);
if (!typeIter)
return std::nullopt;
const FunctionType* outerFunction = get<FunctionType>(follow(*typeIter));
if (!outerFunction)
return std::nullopt;
size_t argument = 0;
for (size_t i = 0; i < call->args.size; ++i)
{
if (call->args.data[i]->location.containsClosed(position))
{
argument = i;
break;
}
}
if (call->self)
argument++;
std::optional<TypeId> argType;
auto [args, tail] = flatten(outerFunction->argTypes);
if (argument < args.size())
argType = args[argument];
if (!argType)
return std::nullopt;
TypeId followed = follow(*argType);
const FunctionType* type = get<FunctionType>(followed);
if (!type)
{
if (const UnionType* unionType = get<UnionType>(followed))
{
if (std::optional<const FunctionType*> nonnullFunction = returnFirstNonnullOptionOfType<FunctionType>(unionType))
type = *nonnullFunction;
}
}
if (!type)
return std::nullopt;
const ScopePtr scope = findScopeAtPosition(*module, position);
if (!scope)
return std::nullopt;
AutocompleteEntry entry;
entry.kind = AutocompleteEntryKind::GeneratedFunction;
entry.typeCorrect = TypeCorrectKind::Correct;
entry.type = argType;
entry.insertText = makeAnonymous(scope, *type);
return std::make_optional(std::move(entry));
}
static AutocompleteResult autocomplete(const SourceModule& sourceModule, const ModulePtr& module, NotNull<BuiltinTypes> builtinTypes,
TypeArena* typeArena, Scope* globalScope, Position position, StringCompletionCallback callback)
{
if (isWithinComment(sourceModule, position))
return {};
std::vector<AstNode*> ancestry = findAncestryAtPositionForAutocomplete(sourceModule, position);
LUAU_ASSERT(!ancestry.empty());
AstNode* node = ancestry.back();
AstExprConstantNil dummy{Location{}};
AstNode* parent = ancestry.size() >= 2 ? ancestry.rbegin()[1] : &dummy;
// If we are inside a body of a function that doesn't have a completed argument list, ignore the body node
if (auto exprFunction = parent->as<AstExprFunction>(); exprFunction && !exprFunction->argLocation && node == exprFunction->body)
{
ancestry.pop_back();
node = ancestry.back();
parent = ancestry.size() >= 2 ? ancestry.rbegin()[1] : &dummy;
}
if (auto indexName = node->as<AstExprIndexName>())
{
auto it = module->astTypes.find(indexName->expr);
if (!it)
return {};
TypeId ty = follow(*it);
PropIndexType indexType = indexName->op == ':' ? PropIndexType::Colon : PropIndexType::Point;
return {autocompleteProps(*module, typeArena, builtinTypes, ty, indexType, ancestry), ancestry, AutocompleteContext::Property};
}
else if (auto typeReference = node->as<AstTypeReference>())
{
if (typeReference->prefix)
return {autocompleteModuleTypes(*module, position, typeReference->prefix->value), ancestry, AutocompleteContext::Type};
else
return {autocompleteTypeNames(*module, position, ancestry), ancestry, AutocompleteContext::Type};
}
else if (node->is<AstTypeError>())
{
return {autocompleteTypeNames(*module, position, ancestry), ancestry, AutocompleteContext::Type};
}
else if (AstStatLocal* statLocal = node->as<AstStatLocal>())
{
if (statLocal->vars.size == 1 && (!statLocal->equalsSignLocation || position < statLocal->equalsSignLocation->begin))
return {{{"function", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, ancestry, AutocompleteContext::Unknown};
else if (statLocal->equalsSignLocation && position >= statLocal->equalsSignLocation->end)
return autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
else
return {};
}
else if (AstStatFor* statFor = extractStat<AstStatFor>(ancestry))
{
if (!statFor->hasDo || position < statFor->doLocation.begin)
{
if (statFor->from->location.containsClosed(position) || statFor->to->location.containsClosed(position) ||
(statFor->step && statFor->step->location.containsClosed(position)))
return autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
if (!statFor->from->is<AstExprError>() && !statFor->to->is<AstExprError>() && (!statFor->step || !statFor->step->is<AstExprError>()))
return {{{"do", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, ancestry, AutocompleteContext::Keyword};
return {};
}
return {autocompleteStatement(sourceModule, *module, ancestry, position), ancestry, AutocompleteContext::Statement};
}
else if (AstStatForIn* statForIn = parent->as<AstStatForIn>(); statForIn && (node->is<AstStatBlock>() || isIdentifier(node)))
{
if (!statForIn->hasIn || position <= statForIn->inLocation.begin)
{
AstLocal* lastName = statForIn->vars.data[statForIn->vars.size - 1];
if (lastName->name == kParseNameError || lastName->location.containsClosed(position))
{
// Here we are either working with a missing binding (as would be the case in a bare "for" keyword) or
// the cursor is still touching a binding name. The user is still typing a new name, so we should not offer
// any suggestions.
return {};
}
return {{{"in", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, ancestry, AutocompleteContext::Keyword};
}
if (!statForIn->hasDo || position <= statForIn->doLocation.begin)
{
LUAU_ASSERT(statForIn->values.size > 0);
AstExpr* lastExpr = statForIn->values.data[statForIn->values.size - 1];
if (lastExpr->location.containsClosed(position))
return autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
if (position > lastExpr->location.end)
return {{{"do", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, ancestry, AutocompleteContext::Keyword};
return {}; // Not sure what this means
}
}
else if (AstStatForIn* statForIn = extractStat<AstStatForIn>(ancestry))
{
// The AST looks a bit differently if the cursor is at a position where only the "do" keyword is allowed.
// ex "for f in f do"
if (!statForIn->hasDo)
return {{{"do", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, ancestry, AutocompleteContext::Keyword};
return {autocompleteStatement(sourceModule, *module, ancestry, position), ancestry, AutocompleteContext::Statement};
}
else if (AstStatWhile* statWhile = parent->as<AstStatWhile>(); node->is<AstStatBlock>() && statWhile)
{
if (!statWhile->hasDo && !statWhile->condition->is<AstStatError>() && position > statWhile->condition->location.end)
{
return autocompleteWhileLoopKeywords(ancestry);
}
if (!statWhile->hasDo || position < statWhile->doLocation.begin)
return autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
if (statWhile->hasDo && position > statWhile->doLocation.end)
return {autocompleteStatement(sourceModule, *module, ancestry, position), ancestry, AutocompleteContext::Statement};
}
else if (AstStatWhile* statWhile = extractStat<AstStatWhile>(ancestry);
(statWhile && (!statWhile->hasDo || statWhile->doLocation.containsClosed(position)) && statWhile->condition &&
!statWhile->condition->location.containsClosed(position)))
{
return autocompleteWhileLoopKeywords(ancestry);
}
else if (AstStatIf* statIf = node->as<AstStatIf>(); statIf && !statIf->elseLocation.has_value())
{
return {{{"else", AutocompleteEntry{AutocompleteEntryKind::Keyword}}, {"elseif", AutocompleteEntry{AutocompleteEntryKind::Keyword}}},
ancestry, AutocompleteContext::Keyword};
}
else if (AstStatIf* statIf = parent->as<AstStatIf>(); statIf && node->is<AstStatBlock>())
{
if (statIf->condition->is<AstExprError>())
return autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
else if (!statIf->thenLocation || statIf->thenLocation->containsClosed(position))
return {{{"then", AutocompleteEntry{AutocompleteEntryKind::Keyword}}}, ancestry, AutocompleteContext::Keyword};
}
else if (AstStatIf* statIf = extractStat<AstStatIf>(ancestry); statIf &&
(!statIf->thenLocation || statIf->thenLocation->containsClosed(position)) &&
(statIf->condition && !statIf->condition->location.containsClosed(position)))
{
AutocompleteEntryMap ret;
ret["then"] = {AutocompleteEntryKind::Keyword};
ret["and"] = {AutocompleteEntryKind::Keyword};
ret["or"] = {AutocompleteEntryKind::Keyword};
return {std::move(ret), ancestry, AutocompleteContext::Keyword};
}
else if (AstStatRepeat* statRepeat = node->as<AstStatRepeat>(); statRepeat && statRepeat->condition->is<AstExprError>())
return autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
else if (AstStatRepeat* statRepeat = extractStat<AstStatRepeat>(ancestry); statRepeat)
return {autocompleteStatement(sourceModule, *module, ancestry, position), ancestry, AutocompleteContext::Statement};
else if (AstExprTable* exprTable = parent->as<AstExprTable>();
exprTable && (node->is<AstExprGlobal>() || node->is<AstExprConstantString>() || node->is<AstExprInterpString>()))
{
for (const auto& [kind, key, value] : exprTable->items)
{
// If item doesn't have a key, maybe the value is actually the key
if (key ? key == node : node->is<AstExprGlobal>() && value == node)
{
if (auto it = module->astExpectedTypes.find(exprTable))
{
auto result = autocompleteProps(*module, typeArena, builtinTypes, *it, PropIndexType::Key, ancestry);
if (auto nodeIt = module->astExpectedTypes.find(node->asExpr()))
autocompleteStringSingleton(*nodeIt, !node->is<AstExprConstantString>(), node, position, result);
if (!key)
{
// If there is "no key," it may be that the user
// intends for the current token to be the key, but
// has yet to type the `=` sign.
//
// If the key type is a union of singleton strings,
// suggest those too.
if (auto ttv = get<TableType>(follow(*it)); ttv && ttv->indexer)
{
autocompleteStringSingleton(ttv->indexer->indexType, false, node, position, result);
}
}
// Remove keys that are already completed
for (const auto& item : exprTable->items)
{
if (!item.key)
continue;
if (auto stringKey = item.key->as<AstExprConstantString>())
result.erase(std::string(stringKey->value.data, stringKey->value.size));
}
// If we know for sure that a key is being written, do not offer general expression suggestions
if (!key)
autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position, result);
return {result, ancestry, AutocompleteContext::Property};
}
break;
}
}
}
else if (AstExprTable* exprTable = node->as<AstExprTable>())
{
AutocompleteEntryMap result;
if (auto it = module->astExpectedTypes.find(exprTable))
{
result = autocompleteProps(*module, typeArena, builtinTypes, *it, PropIndexType::Key, ancestry);
// If the key type is a union of singleton strings,
// suggest those too.
if (auto ttv = get<TableType>(follow(*it)); ttv && ttv->indexer)
{
autocompleteStringSingleton(ttv->indexer->indexType, false, node, position, result);
}
// Remove keys that are already completed
for (const auto& item : exprTable->items)
{
if (!item.key)
continue;
if (auto stringKey = item.key->as<AstExprConstantString>())
result.erase(std::string(stringKey->value.data, stringKey->value.size));
}
}
// Also offer general expression suggestions
autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position, result);
return {result, ancestry, AutocompleteContext::Property};
}
else if (isIdentifier(node) && (parent->is<AstStatExpr>() || parent->is<AstStatError>()))
return {autocompleteStatement(sourceModule, *module, ancestry, position), ancestry, AutocompleteContext::Statement};
if (std::optional<AutocompleteEntryMap> ret = autocompleteStringParams(sourceModule, module, ancestry, position, callback))
{
return {*ret, ancestry, AutocompleteContext::String};
}
else if (node->is<AstExprConstantString>() || isSimpleInterpolatedString(node))
{
AutocompleteEntryMap result;
if (auto it = module->astExpectedTypes.find(node->asExpr()))
autocompleteStringSingleton(*it, false, node, position, result);
if (ancestry.size() >= 2)
{
if (auto idxExpr = ancestry.at(ancestry.size() - 2)->as<AstExprIndexExpr>())
{
if (auto it = module->astTypes.find(idxExpr->expr))
autocompleteProps(*module, typeArena, builtinTypes, follow(*it), PropIndexType::Point, ancestry, result);
}
else if (auto binExpr = ancestry.at(ancestry.size() - 2)->as<AstExprBinary>())
{
if (binExpr->op == AstExprBinary::CompareEq || binExpr->op == AstExprBinary::CompareNe)
{
if (auto it = module->astTypes.find(node == binExpr->left ? binExpr->right : binExpr->left))
autocompleteStringSingleton(*it, false, node, position, result);
}
}
}
return {result, ancestry, AutocompleteContext::String};
}
else if (stringPartOfInterpString(node, position))
{
// We're not a simple interpolated string, we're something like `a{"b"}@1`, and we
// can't know what to format to
AutocompleteEntryMap map;
return {map, ancestry, AutocompleteContext::String};
}
if (node->is<AstExprConstantNumber>())
return {};
if (node->asExpr())
{
AutocompleteResult ret = autocompleteExpression(sourceModule, *module, builtinTypes, typeArena, ancestry, position);
if (std::optional<AutocompleteEntry> generated = makeAnonymousAutofilled(module, position, node, ancestry))
ret.entryMap[kGeneratedAnonymousFunctionEntryName] = std::move(*generated);
return ret;
}
else if (node->asStat())
return {autocompleteStatement(sourceModule, *module, ancestry, position), ancestry, AutocompleteContext::Statement};
return {};
}
AutocompleteResult autocomplete(Frontend& frontend, const ModuleName& moduleName, Position position, StringCompletionCallback callback)
{
const SourceModule* sourceModule = frontend.getSourceModule(moduleName);
if (!sourceModule)
return {};
ModulePtr module;
if (FFlag::DebugLuauDeferredConstraintResolution)
module = frontend.moduleResolver.getModule(moduleName);
else
module = frontend.moduleResolverForAutocomplete.getModule(moduleName);
if (!module)
return {};
NotNull<BuiltinTypes> builtinTypes = frontend.builtinTypes;
Scope* globalScope;
if (FFlag::DebugLuauDeferredConstraintResolution)
globalScope = frontend.globals.globalScope.get();
else
globalScope = frontend.globalsForAutocomplete.globalScope.get();
TypeArena typeArena;
return autocomplete(*sourceModule, module, builtinTypes, &typeArena, globalScope, position, callback);
}
} // namespace Luau