Files
Fig/src/evaluator.cpp
2025-12-22 17:38:52 +08:00

782 lines
41 KiB
C++

#include <evaluator.hpp>
#include <builtins.hpp>
#include <utils.hpp>
namespace Fig
{
Value Evaluator::__evalOp(Ast::Operator op, const Value &lhs, const Value &rhs)
{
using Fig::Ast::Operator;
switch (op)
{
case Operator::Add: return lhs + rhs;
case Operator::Subtract: return lhs - rhs;
case Operator::Multiply: return lhs * rhs;
case Operator::Divide: return lhs / rhs;
case Operator::Modulo: return lhs % rhs;
case Operator::Power: return power(lhs, rhs);
case Operator::And: return lhs && rhs;
case Operator::Or: return lhs || rhs;
case Operator::Not: return !lhs;
case Operator::Equal: return Value(lhs == rhs);
case Operator::NotEqual: return Value(lhs != rhs);
case Operator::Less: return lhs < rhs;
case Operator::LessEqual: return lhs <= rhs;
case Operator::Greater: return lhs > rhs;
case Operator::GreaterEqual: return lhs >= rhs;
case Operator::BitAnd: return bit_and(lhs, rhs);
case Operator::BitOr: return bit_or(lhs, rhs);
case Operator::BitXor: return bit_xor(lhs, rhs);
case Operator::BitNot: return bit_not(lhs);
case Operator::ShiftLeft: return shift_left(lhs, rhs);
case Operator::ShiftRight: return shift_right(lhs, rhs);
// case Operator::Walrus: {
// static constexpr char WalrusErrorName[] = "WalrusError";
// throw EvaluatorError<WalrusErrorName>(FStringView(u8"Walrus operator is not supported"), currentAddressInfo); // using parent address info for now
// }
default:
throw RuntimeError(FStringView(u8"Unsupported operator"));
}
}
Value Evaluator::evalBinary(const Ast::BinaryExpr &binExp)
{
if (binExp->op == Ast::Operator::Dot)
{
const Value &lhs = eval(binExp->lexp);
if (!lhs.is<StructInstance>())
{
static constexpr char AccessOpObjectNotStructError[] = "AccessOpObjectNotStructError";
throw EvaluatorError<AccessOpObjectNotStructError>(FStringView(
std::format("Object not a struct")),
binExp->lexp->getAAI());
}
const StructInstanceT &st = lhs.as<StructInstance>().getValue();
Ast::VarExpr varExp;
if (!(varExp = std::dynamic_pointer_cast<Ast::VarExprAst>(binExp->rexp)))
{
static constexpr char AccessOpNotAFieldNameError[] = "AccessOpNotAFieldNameError";
throw EvaluatorError<AccessOpNotAFieldNameError>(FStringView(
std::format("{} is not a field name", binExp->rexp->toString().toBasicString())),
binExp->rexp->getAAI());
}
FString member = varExp->name;
auto structTypeNameOpt = currentContext->getStructName(st.parentId);
if (!structTypeNameOpt) throw RuntimeError(FStringView("Can't get struct type name"));
FString structTypeName = *structTypeNameOpt;
if (!st.localContext->containsInThisScope(member))
{
static constexpr char NoAttributeError[] = "NoAttributeError";
throw EvaluatorError<NoAttributeError>(FStringView(
std::format("Struct `{}` has no attribute '{}'", structTypeName.toBasicString(), member.toBasicString())),
binExp->rexp->getAAI());
}
return *st.localContext->get(member); // safe
}
if (binExp->op == Ast::Operator::Assign)
{
Ast::VarExpr varExp;
if (!(varExp = std::dynamic_pointer_cast<Ast::VarExprAst>(binExp->rexp)))
{
static constexpr char AssignToRightValueError[] = "AssignToRightValueError";
throw EvaluatorError<AssignToRightValueError>(FStringView(
std::format("Can't assign to right value {}", binExp->lexp->toString().toBasicString())),
binExp->lexp->getAAI());
}
const FString& varName = varExp->name;
if (!currentContext->contains(varName))
{
static constexpr char VariableNotFoundErrorName[] = "VariableNotFoundError";
throw EvaluatorError<VariableNotFoundErrorName>(FStringView(std::format("Variable '{}' not defined", varName.toBasicString())), currentAddressInfo);
}
}
return __evalOp(binExp->op, eval(binExp->lexp), eval(binExp->rexp));
}
Value Evaluator::evalUnary(const Ast::UnaryExpr &unExp)
{
using Fig::Ast::Operator;
switch (unExp->op)
{
case Operator::Not:
return !eval(unExp->exp);
case Operator::Subtract:
return -eval(unExp->exp);
case Operator::BitNot:
return bit_not(eval(unExp->exp));
default:
throw RuntimeError(FStringView(std::format("Unsupported unary operator: {}", magic_enum::enum_name(unExp->op))));
}
}
Value Evaluator::evalFunctionCall(const Function &fn, const Ast::FunctionArguments &fnArgs, FString fnName)
{
FunctionStruct fnStruct = fn.getValue();
Ast::FunctionCallArgs evaluatedArgs;
if (fnStruct.isBuiltin)
{
for (const auto &argExpr : fnArgs.argv)
{
evaluatedArgs.argv.push_back(eval(argExpr));
}
if (fnStruct.builtinParamCount != -1 && fnStruct.builtinParamCount != evaluatedArgs.getLength())
{
static constexpr char BuiltinArgumentMismatchErrorName[] = "BuiltinArgumentMismatchError";
throw EvaluatorError<BuiltinArgumentMismatchErrorName>(FStringView(std::format("Builtin function '{}' expects {} arguments, but {} were provided", fnName.toBasicString(), fnStruct.builtinParamCount, evaluatedArgs.getLength())), currentAddressInfo);
}
return fnStruct.builtin(evaluatedArgs.argv);
}
// check argument, all types of parameters
Ast::FunctionParameters fnParas = fnStruct.paras;
if (fnArgs.getLength() < fnParas.posParas.size() || fnArgs.getLength() > fnParas.size())
{
static constexpr char ArgumentMismatchErrorName[] = "ArgumentMismatchError";
throw EvaluatorError<ArgumentMismatchErrorName>(FStringView(std::format("Function '{}' expects {} to {} arguments, but {} were provided", fnName.toBasicString(), fnParas.posParas.size(), fnParas.size(), fnArgs.getLength())), currentAddressInfo);
}
// positional parameters type check
size_t i;
for (i = 0; i < fnParas.posParas.size(); i++)
{
TypeInfo expectedType(fnParas.posParas[i].second); // look up type info, if exists a type with the name, use it, else throw
Value argVal = eval(fnArgs.argv[i]);
TypeInfo actualType = argVal.getTypeInfo();
if (expectedType != actualType and expectedType != ValueType::Any)
{
static constexpr char ArgumentTypeMismatchErrorName[] = "ArgumentTypeMismatchError";
throw EvaluatorError<ArgumentTypeMismatchErrorName>(FStringView(std::format("In function '{}', argument '{}' expects type '{}', but got type '{}'", fnName.toBasicString(), fnParas.posParas[i].first.toBasicString(), expectedType.toString().toBasicString(), actualType.toString().toBasicString())), currentAddressInfo);
}
evaluatedArgs.argv.push_back(argVal);
}
// default parameters type check
for (; i < fnArgs.getLength(); i++)
{
size_t defParamIndex = i - fnParas.posParas.size();
TypeInfo expectedType = fnParas.defParas[defParamIndex].second.first;
Value defaultVal = eval(fnParas.defParas[defParamIndex].second.second);
if (expectedType != defaultVal.getTypeInfo() and expectedType != ValueType::Any)
{
static constexpr char DefaultParameterTypeErrorName[] = "DefaultParameterTypeError";
throw EvaluatorError<DefaultParameterTypeErrorName>(FStringView(std::format("In function '{}', default parameter '{}' has type '{}', which does not match the expected type '{}'", fnName.toBasicString(), fnParas.defParas[defParamIndex].first.toBasicString(), defaultVal.getTypeInfo().toString().toBasicString(), expectedType.toString().toBasicString())), currentAddressInfo);
}
Value argVal = eval(fnArgs.argv[i]);
TypeInfo actualType = argVal.getTypeInfo();
if (expectedType != actualType and expectedType != ValueType::Any)
{
static constexpr char ArgumentTypeMismatchErrorName[] = "ArgumentTypeMismatchError";
throw EvaluatorError<ArgumentTypeMismatchErrorName>(FStringView(std::format("In function '{}', argument '{}' expects type '{}', but got type '{}'", fnName.toBasicString(), fnParas.defParas[defParamIndex].first.toBasicString(), expectedType.toString().toBasicString(), actualType.toString().toBasicString())), currentAddressInfo);
}
evaluatedArgs.argv.push_back(argVal);
}
// default parameters filling
for (; i < fnParas.size(); i++)
{
size_t defParamIndex = i - fnParas.posParas.size();
Value defaultVal = eval(fnParas.defParas[defParamIndex].second.second);
evaluatedArgs.argv.push_back(defaultVal);
}
// create new context for function call
auto newContext = std::make_shared<Context>(FString(std::format("<Function {}()>", fnName.toBasicString())),
fnStruct.closureContext);
auto previousContext = currentContext;
currentContext = newContext;
// define parameters in new context
for (size_t j = 0; j < fnParas.size(); j++)
{
FString paramName;
TypeInfo paramType;
if (j < fnParas.posParas.size())
{
paramName = fnParas.posParas[j].first;
paramType = fnParas.posParas[j].second;
}
else
{
size_t defParamIndex = j - fnParas.posParas.size();
paramName = fnParas.defParas[defParamIndex].first;
paramType = fnParas.defParas[defParamIndex].second.first;
}
AccessModifier argAm = AccessModifier::Const;
currentContext->def(paramName, paramType, argAm, evaluatedArgs.argv[j]);
}
// execute function body
Value retVal = Value::getNullInstance();
for (const auto &stmt : fnStruct.body->stmts)
{
StatementResult sr = evalStatement(stmt);
if (sr.shouldReturn())
{
retVal = sr.result;
break;
}
}
currentContext = previousContext;
if (fnStruct.retType != retVal.getTypeInfo() and fnStruct.retType != ValueType::Any)
{
static constexpr char ReturnTypeMismatchErrorName[] = "ReturnTypeMismatchError";
throw EvaluatorError<ReturnTypeMismatchErrorName>(FStringView(std::format("Function '{}' expects return type '{}', but got type '{}'", fnName.toBasicString(), fnStruct.retType.toString().toBasicString(), retVal.getTypeInfo().toString().toBasicString())), currentAddressInfo);
}
return retVal;
}
Value Evaluator::eval(Ast::Expression exp)
{
using Fig::Ast::AstType;
switch (exp->getType())
{
case AstType::ValueExpr: {
auto valExp = std::dynamic_pointer_cast<Ast::ValueExprAst>(exp);
return valExp->val;
}
case AstType::VarExpr: {
auto varExp = std::dynamic_pointer_cast<Ast::VarExprAst>(exp);
auto val = currentContext->get(varExp->name);
if (val.has_value())
{
return val.value();
}
static constexpr char UndefinedVariableErrorName[] = "UndefinedVariableError";
throw EvaluatorError<UndefinedVariableErrorName>(FStringView(std::format("Variable '{}' is not defined in the current scope", varExp->name.toBasicString())), varExp->getAAI());
}
case AstType::BinaryExpr: {
auto binExp = std::dynamic_pointer_cast<Ast::BinaryExprAst>(exp);
return evalBinary(binExp);
}
case AstType::UnaryExpr: {
auto unExp = std::dynamic_pointer_cast<Ast::UnaryExprAst>(exp);
return evalUnary(unExp);
}
case AstType::FunctionCall: {
auto fnCall = std::dynamic_pointer_cast<Ast::FunctionCallExpr>(exp);
Value calleeVal = eval(fnCall->callee);
if (!calleeVal.is<Function>())
{
static constexpr char NotAFunctionErrorName[] = "NotAFunctionError";
throw EvaluatorError<NotAFunctionErrorName>(
FStringView(std::format(
"'{}' is not a function or callable",
calleeVal.toString().toBasicString())),
currentAddressInfo);
}
Function fn = calleeVal.as<Function>();
FString fnName = u8"<anonymous>";
if (auto var = std::dynamic_pointer_cast<Ast::VarExprAst>(fnCall->callee))
fnName = var->name; // try to get function name
return evalFunctionCall(fn, fnCall->arg, fnName);
}
case AstType::FunctionLiteralExpr: {
auto fn = std::dynamic_pointer_cast<Ast::FunctionLiteralExprAst>(exp);
if (fn->isExprMode())
{
Ast::BlockStatement body = std::make_shared<Ast::BlockStatementAst>();
body->setAAI(fn->getExprBody()->getAAI());
Ast::Statement retSt = std::make_shared<Ast::ReturnSt>(fn->getExprBody());
retSt->setAAI(fn->getExprBody()->getAAI());
body->stmts.push_back(retSt);
return Function(
fn->paras,
ValueType::Any,
body,
currentContext);
}
else
{
Ast::BlockStatement body = fn->getBlockBody();
return Function(
fn->paras,
ValueType::Any,
body,
currentContext);
}
}
case AstType::InitExpr: {
auto initExpr = std::dynamic_pointer_cast<Ast::InitExprAst>(exp);
if (!currentContext->contains(initExpr->structName))
{
static constexpr char StructNotFoundErrorName[] = "StructNotFoundError";
throw EvaluatorError<StructNotFoundErrorName>(FStringView(std::format("Structure type '{}' not found", initExpr->structName.toBasicString())), initExpr->getAAI());
}
Value structTypeVal = currentContext->get(initExpr->structName).value();
if (!structTypeVal.is<StructType>())
{
static constexpr char NotAStructTypeErrorName[] = "NotAStructTypeError";
throw EvaluatorError<NotAStructTypeErrorName>(FStringView(std::format("'{}' is not a structure type", initExpr->structName.toBasicString())), initExpr->getAAI());
}
const StructT &structT = structTypeVal.as<StructType>().getValue();
ContextPtr defContext = structT.defContext; // definition context
// check init args
size_t minArgs = 0;
size_t maxArgs = structT.fields.size();
for (auto &f : structT.fields)
{
if (f.defaultValue == nullptr) minArgs++;
}
size_t got = initExpr->args.size();
if (got > maxArgs || got < minArgs)
{
static constexpr char StructInitArgumentMismatchErrorName[] = "StructInitArgumentMismatchError";
throw EvaluatorError<StructInitArgumentMismatchErrorName>(FStringView(std::format("Structure '{}' expects {} to {} fields, but {} were provided", initExpr->structName.toBasicString(), minArgs, maxArgs, initExpr->args.size())), initExpr->getAAI());
}
std::vector<std::pair<FString, Value>> evaluatedArgs;
for (const auto &[argName, argExpr] : initExpr->args)
{
evaluatedArgs.push_back({argName, eval(argExpr)});
}
ContextPtr instanceCtx = std::make_shared<Context>(
FString(std::format("<StructInstance {}>", initExpr->structName.toBasicString())),
currentContext);
/*
3 ways of calling constructor
.1 Person {"Fig", 1, "IDK"};
.2 Person {name: "Fig", age: 1, sex: "IDK"}; // can be unordered
.3 Person {name, age, sex};
*/
{
using enum Ast::InitExprAst::InitMode;
if (initExpr->initMode == Positional)
{
for (size_t i = 0; i < maxArgs; ++i)
{
const Field &field = structT.fields[i];
const FString &fieldName = field.name;
const TypeInfo &expectedType = field.type;
if (i >= evaluatedArgs.size())
{
// we've checked argument count before, so here must be a default value
ContextPtr previousContext = currentContext;
currentContext = defContext; // evaluate default value in definition context
Value defaultVal = eval(field.defaultValue); // it can't be null here
currentContext = previousContext;
// type check
if (expectedType != defaultVal.getTypeInfo() && expectedType != ValueType::Any)
{
static constexpr char StructFieldTypeMismatchErrorName[] = "StructFieldTypeMismatchError";
throw EvaluatorError<StructFieldTypeMismatchErrorName>(FStringView(std::format("In structure '{}', field '{}' expects type '{}', but got type '{}'", initExpr->structName.toBasicString(), fieldName.toBasicString(), expectedType.toString().toBasicString(), defaultVal.getTypeInfo().toString().toBasicString())), initExpr->getAAI());
}
instanceCtx->def(fieldName, expectedType, field.am, defaultVal);
continue;
}
const Value &argVal = evaluatedArgs[i].second;
if (expectedType != argVal.getTypeInfo() && expectedType != ValueType::Any)
{
static constexpr char StructFieldTypeMismatchErrorName[] = "StructFieldTypeMismatchError";
throw EvaluatorError<StructFieldTypeMismatchErrorName>(FStringView(std::format("In structure '{}', field '{}' expects type '{}', but got type '{}'", initExpr->structName.toBasicString(), fieldName.toBasicString(), expectedType.toString().toBasicString(), argVal.getTypeInfo().toString().toBasicString())), initExpr->getAAI());
}
instanceCtx->def(fieldName, expectedType, field.am, argVal);
}
}
else
{
// named / shorthand init
for (size_t i = 0; i < maxArgs; ++i)
{
const Field &field = structT.fields[i];
const FString &fieldName = (field.name.empty() ? evaluatedArgs[i].first : field.name);
if (instanceCtx->containsInThisScope(fieldName))
{
static constexpr char StructFieldRedeclarationErrorName[] = "StructFieldRedeclarationError";
throw EvaluatorError<StructFieldRedeclarationErrorName>(FStringView(std::format("Field '{}' already initialized in structure '{}'", fieldName.toBasicString(), initExpr->structName.toBasicString())), initExpr->getAAI());
}
if (i + 1 > got)
{
// use default value
ContextPtr previousContext = currentContext;
currentContext = defContext; // evaluate default value in definition context
Value defaultVal = eval(field.defaultValue); // it can't be null here
currentContext = previousContext;
// type check
const TypeInfo &expectedType = field.type;
if (expectedType != defaultVal.getTypeInfo() && expectedType != ValueType::Any)
{
static constexpr char StructFieldTypeMismatchErrorName[] = "StructFieldTypeMismatchError";
throw EvaluatorError<StructFieldTypeMismatchErrorName>(FStringView(std::format("In structure '{}', field '{}' expects type '{}', but got type '{}'", initExpr->structName.toBasicString(), fieldName.toBasicString(), expectedType.toString().toBasicString(), defaultVal.getTypeInfo().toString().toBasicString())), initExpr->getAAI());
}
instanceCtx->def(fieldName, field.type, field.am, defaultVal);
continue;
}
const Value &argVal = evaluatedArgs[i].second;
if (field.type != argVal.getTypeInfo() && field.type != ValueType::Any)
{
static constexpr char StructFieldTypeMismatchErrorName[] = "StructFieldTypeMismatchError";
throw EvaluatorError<StructFieldTypeMismatchErrorName>(FStringView(std::format("In structure '{}', field '{}' expects type '{}', but got type '{}'", initExpr->structName.toBasicString(), fieldName.toBasicString(), field.type.toString().toBasicString(), argVal.getTypeInfo().toString().toBasicString())), initExpr->getAAI());
}
instanceCtx->def(fieldName, field.type, field.am, argVal);
}
}
}
return StructInstance(structT.id, instanceCtx);
}
default:
throw RuntimeError(FStringView("Unknown expression type:" + std::to_string(static_cast<int>(exp->getType()))));
return Value::getNullInstance();
}
}
StatementResult Evaluator::evalBlockStatement(const Ast::BlockStatement &blockSt, ContextPtr context)
{
auto previousContext = currentContext;
if (context)
{
currentContext = context;
}
else
{
currentContext = std::make_shared<Context>(FString(std::format("<Block {}:{}>", blockSt->getAAI().line, blockSt->getAAI().column)), currentContext);
}
StatementResult lstResult = StatementResult::normal();
for (const auto &s : blockSt->stmts)
{
StatementResult sr = evalStatement(s);
if (!sr.isNormal())
{
lstResult = sr;
break;
}
}
currentContext = previousContext;
return lstResult;
}
StatementResult Evaluator::evalStatement(const Ast::Statement &stmt)
{
using Fig::Ast::AstType;
currentAddressInfo = stmt->getAAI();
switch (stmt->getType())
{
case AstType::VarDefSt: {
auto varDef = std::dynamic_pointer_cast<Ast::VarDefAst>(stmt);
if (currentContext->contains(varDef->name))
{
static constexpr char RedeclarationErrorName[] = "RedeclarationError";
throw EvaluatorError<RedeclarationErrorName>(FStringView(std::format("Variable '{}' already defined in this scope", varDef->name.toBasicString())), currentAddressInfo);
}
Value val;
TypeInfo varTypeInfo;
if (varDef->typeName == Parser::varDefTypeFollowed)
{
// has expr
val = eval(varDef->expr);
varTypeInfo = val.getTypeInfo();
}
else if (varDef->expr)
{
val = eval(varDef->expr);
if (varDef->typeName != ValueType::Any.name)
{
TypeInfo expectedType(varDef->typeName);
TypeInfo actualType = val.getTypeInfo();
if (expectedType != actualType and expectedType != ValueType::Any)
{
static constexpr char VariableTypeMismatchErrorName[] = "VariableTypeMismatchError";
throw EvaluatorError<VariableTypeMismatchErrorName>(FStringView(std::format("Variable '{}' expects type '{}', but got type '{}'", varDef->name.toBasicString(), expectedType.toString().toBasicString(), actualType.toString().toBasicString())), varDef->getAAI());
}
}
}
else if (!varDef->typeName.empty())
{
varTypeInfo = TypeInfo(varDef->typeName); // may throw
val = Value::defaultValue(varTypeInfo);
}
AccessModifier am = (varDef->isPublic ? (varDef->isConst ? AccessModifier::PublicConst : AccessModifier::Public) : (varDef->isConst ? AccessModifier::Const : AccessModifier::Normal));
currentContext->def(varDef->name, varTypeInfo, am, val);
return StatementResult::normal();
}
case AstType::ExpressionStmt: {
auto exprSt = std::dynamic_pointer_cast<Ast::ExpressionStmtAst>(stmt);
eval(exprSt->exp);
return StatementResult::normal();
};
case AstType::BlockStatement: {
auto blockSt = std::dynamic_pointer_cast<Ast::BlockStatementAst>(stmt);
return evalBlockStatement(blockSt); // auto create new context in block statement
};
case AstType::FunctionDefSt: {
auto fnDef = std::dynamic_pointer_cast<Ast::FunctionDefSt>(stmt);
if (currentContext->contains(fnDef->name))
{
static constexpr char RedeclarationErrorName[] = "RedeclarationError";
throw EvaluatorError<RedeclarationErrorName>(FStringView(std::format("Function '{}' already defined in this scope", fnDef->name.toBasicString())), currentAddressInfo);
}
AccessModifier am = (fnDef->isPublic ? AccessModifier::PublicConst : AccessModifier::Const);
currentContext->def(
fnDef->name,
ValueType::Function,
am,
Value(Function(
fnDef->paras,
TypeInfo(fnDef->retType),
fnDef->body,
currentContext)));
return StatementResult::normal();
};
case AstType::StructSt: {
auto stDef = std::dynamic_pointer_cast<Ast::StructDefSt>(stmt);
if (currentContext->containsInThisScope(stDef->name))
{
static constexpr char RedeclarationErrorName[] = "RedeclarationError";
throw EvaluatorError<RedeclarationErrorName>(FStringView(std::format("Structure '{}' already defined in this scope", stDef->name.toBasicString())), currentAddressInfo);
}
std::vector<Field> fields;
std::vector<FString> _fieldNames;
for (Ast::StructDefField field : stDef->fields)
{
if (Utils::vectorContains(field.fieldName, _fieldNames))
{
static constexpr char RedeclarationErrorName[] = "RedeclarationError";
throw EvaluatorError<RedeclarationErrorName>(FStringView(std::format("Field '{}' already defined in structure '{}'", field.fieldName.toBasicString(), stDef->name.toBasicString())), currentAddressInfo);
}
fields.push_back(Field(field.am, field.fieldName, TypeInfo(field.tiName), field.defaultValueExpr));
}
ContextPtr defContext(currentContext);
AccessModifier am = (stDef->isPublic ? AccessModifier::PublicConst : AccessModifier::Const);
TypeInfo _(stDef->name, true); // register type name
currentContext->def(
stDef->name,
ValueType::StructType,
am,
Value(StructType(
defContext,
fields)));
return StatementResult::normal();
}
// case AstType::VarAssignSt: {
// auto varAssign = std::dynamic_pointer_cast<Ast::VarAssignSt>(stmt);
// if (!currentContext->contains(varAssign->varName))
// {
// static constexpr char VariableNotFoundErrorName[] = "VariableNotFoundError";
// throw EvaluatorError<VariableNotFoundErrorName>(FStringView(std::format("Variable '{}' not defined", varAssign->varName.toBasicString())), currentAddressInfo);
// }
// if (!currentContext->isVariableMutable(varAssign->varName))
// {
// static constexpr char ConstAssignmentErrorName[] = "ConstAssignmentError";
// throw EvaluatorError<ConstAssignmentErrorName>(FStringView(std::format("Cannot assign to constant variable '{}'", varAssign->varName.toBasicString())), currentAddressInfo);
// }
// Value val = eval(varAssign->valueExpr);
// if (currentContext->getTypeInfo(varAssign->varName) != ValueType::Any)
// {
// TypeInfo expectedType = currentContext->getTypeInfo(varAssign->varName);
// TypeInfo actualType = val.getTypeInfo();
// if (expectedType != actualType)
// {
// static constexpr char VariableTypeMismatchErrorName[] = "VariableTypeMismatchError";
// throw EvaluatorError<VariableTypeMismatchErrorName>(FStringView(std::format("assigning: Variable '{}' expects type '{}', but got type '{}'", varAssign->varName.toBasicString(), expectedType.toString().toBasicString(), actualType.toString().toBasicString())), currentAddressInfo);
// }
// }
// currentContext->set(varAssign->varName, val);
// return StatementResult::normal();
// };
case AstType::IfSt: {
auto ifSt = std::dynamic_pointer_cast<Ast::IfSt>(stmt);
Value condVal = eval(ifSt->condition);
if (condVal.getTypeInfo() != ValueType::Bool)
{
static constexpr char ConditionTypeErrorName[] = "ConditionTypeError";
throw EvaluatorError<ConditionTypeErrorName>(FStringView(u8"If condition must be boolean"), currentAddressInfo);
}
if (condVal.as<Bool>().getValue())
{
return evalBlockStatement(ifSt->body);
}
// else
for (const auto &elif : ifSt->elifs)
{
Value elifCondVal = eval(elif->condition);
if (elifCondVal.getTypeInfo() != ValueType::Bool)
{
static constexpr char ConditionTypeErrorName[] = "ConditionTypeError";
throw EvaluatorError<ConditionTypeErrorName>(FStringView(u8"Else-if condition must be boolean"), currentAddressInfo);
}
if (elifCondVal.as<Bool>().getValue())
{
return evalBlockStatement(elif->body);
}
}
if (ifSt->els)
{
return evalBlockStatement(ifSt->els->body);
}
return StatementResult::normal();
};
case AstType::WhileSt: {
auto whileSt = std::dynamic_pointer_cast<Ast::WhileSt>(stmt);
while (true)
{
Value condVal = eval(whileSt->condition);
if (condVal.getTypeInfo() != ValueType::Bool)
{
static constexpr char ConditionTypeErrorName[] = "ConditionTypeError";
throw EvaluatorError<ConditionTypeErrorName>(FStringView(u8"While condition must be boolean"), whileSt->condition->getAAI());
}
if (!condVal.as<Bool>().getValue())
{
break;
}
ContextPtr loopContext = std::make_shared<Context>(
FString(std::format("<While {}:{}>",
whileSt->getAAI().line, whileSt->getAAI().column)),
currentContext); // every loop has its own context
StatementResult sr = evalBlockStatement(whileSt->body, loopContext);
if (sr.shouldReturn())
{
return sr;
}
if (sr.shouldBreak())
{
break;
}
if (sr.shouldContinue())
{
continue;
}
}
return StatementResult::normal();
};
case AstType::ForSt: {
auto forSt = std::dynamic_pointer_cast<Ast::ForSt>(stmt);
ContextPtr loopContext = std::make_shared<Context>(
FString(std::format("<For {}:{}>",
forSt->getAAI().line, forSt->getAAI().column)),
currentContext); // for loop has its own context
ContextPtr previousContext = currentContext;
currentContext = loopContext;
evalStatement(forSt->initSt); // ignore init statement result
size_t iteration = 0;
while (true) // use while loop to simulate for loop, cause we need to check condition type every iteration
{
Value condVal = eval(forSt->condition);
if (condVal.getTypeInfo() != ValueType::Bool)
{
static constexpr char ConditionTypeErrorName[] = "ConditionTypeError";
throw EvaluatorError<ConditionTypeErrorName>(FStringView(u8"For condition must be boolean"), forSt->condition->getAAI());
}
if (!condVal.as<Bool>().getValue())
{
break;
}
iteration++;
ContextPtr iterationContext = std::make_shared<Context>(
FString(std::format("<For {}:{}, Iteration {}>",
forSt->getAAI().line, forSt->getAAI().column, iteration)),
loopContext); // every loop has its own context
StatementResult sr = evalBlockStatement(forSt->body, iterationContext);
if (sr.shouldReturn())
{
currentContext = previousContext; // restore context before return
return sr;
}
if (sr.shouldBreak())
{
break;
}
if (sr.shouldContinue())
{
// continue to next iteration
continue;
}
currentContext = loopContext; // let increment statement be in loop context
evalStatement(forSt->incrementSt); // ignore increment statement result
}
currentContext = previousContext; // restore context
return StatementResult::normal();
}
case AstType::ReturnSt: {
if (!currentContext->parent)
{
static constexpr char ReturnOutsideFunctionErrorName[] = "ReturnOutsideFunctionError";
throw EvaluatorError<ReturnOutsideFunctionErrorName>(FStringView(u8"'return' statement outside function"), currentAddressInfo);
}
if (!currentContext->isInFunctionContext())
{
static constexpr char ReturnOutsideFunctionErrorName[] = "ReturnOutsideFunctionError";
throw EvaluatorError<ReturnOutsideFunctionErrorName>(FStringView(u8"'return' statement outside function"), currentAddressInfo);
}
auto returnSt = std::dynamic_pointer_cast<Ast::ReturnSt>(stmt);
return StatementResult::returnFlow(eval(returnSt->retValue));
};
case AstType::BreakSt: {
if (!currentContext->parent)
{
static constexpr char BreakOutsideLoopErrorName[] = "BreakOutsideLoopError";
throw EvaluatorError<BreakOutsideLoopErrorName>(FStringView(u8"'break' statement outside loop"), currentAddressInfo);
}
if (!currentContext->isInLoopContext())
{
static constexpr char BreakOutsideLoopErrorName[] = "BreakOutsideLoopError";
throw EvaluatorError<BreakOutsideLoopErrorName>(FStringView(u8"'break' statement outside loop"), currentAddressInfo);
}
return StatementResult::breakFlow();
};
case AstType::ContinueSt: {
if (!currentContext->parent)
{
static constexpr char ContinueOutsideLoopErrorName[] = "ContinueOutsideLoopError";
throw EvaluatorError<ContinueOutsideLoopErrorName>(FStringView(u8"'continue' statement outside loop"), currentAddressInfo);
}
if (!currentContext->isInLoopContext())
{
static constexpr char ContinueOutsideLoopErrorName[] = "ContinueOutsideLoopError";
throw EvaluatorError<ContinueOutsideLoopErrorName>(FStringView(u8"'continue' statement outside loop"), currentAddressInfo);
}
return StatementResult::continueFlow();
};
default:
throw RuntimeError(FStringView(std::string("Unknown statement type:") + magic_enum::enum_name(stmt->getType()).data()));
}
return StatementResult::normal();
}
void Evaluator::run()
{
for (auto ast : asts)
{
currentAddressInfo = ast->getAAI();
if (std::dynamic_pointer_cast<Ast::ExpressionStmtAst>(ast))
{
auto exprAst = std::dynamic_pointer_cast<Ast::ExpressionStmtAst>(ast);
Ast::Expression exp = exprAst->exp;
eval(exp);
}
else if (dynamic_cast<Ast::StatementAst *>(ast.get()))
{
auto stmtAst = std::dynamic_pointer_cast<Ast::StatementAst>(ast);
evalStatement(stmtAst);
}
else
{
throw RuntimeError(FStringView(u8"Unknown AST type"));
}
}
}
void Evaluator::printStackTrace() const
{
if (currentContext)
currentContext->printStackTrace();
else
std::cerr << "[STACK TRACE] (No context has been loaded)\n";
}
} // namespace Fig