Plan

refact: 在xmake.lua中优化构建设置

.clang-format

@@ -6,7 +6,7 @@ Language: Cpp
 AccessModifierOffset: -4
 
 # 开括号(开圆括号、开尖括号、开方括号)后的对齐: Align, DontAlign, AlwaysBreak(总是在开括号后换行)
-AlignAfterOpenBracket: DontAlign
+AlignAfterOpenBracket: AlwaysBreak
 
 # 连续赋值时，对齐所有等号
 AlignConsecutiveAssignments: true

ExampleCodes/SpeedTest/fib.py

@@ -1,11 +1,11 @@
 from time import time as tt
 
 def fib(x:int) -> int:
-    if x <= 1:  return x;
+    if x <= 1:  return x
     return fib(x-1) + fib(x-2)
 
 if __name__ == '__main__':
     t0 = tt()
-    result = fib(30)
+    result = fib(35)
     t1 = tt()
     print('cost: ',t1-t0, 'result:', result)

README.md

@@ -1,5 +1,7 @@
 # Fig
 
+## tmd赶工代码质量太差了暑假我要重构
+
 <picture>
   <source media="(prefers-color-scheme: dark)" srcset="./Logo/LogoDark.svg">
   <img src="./Logo/Logo.svg" alt="Fig Logo" width="200">

README_zh-CN.md

@@ -1,5 +1,7 @@
 # Fig
 
+## tmd赶工代码质量太差了暑假我要重构
+
 <picture>
   <source media="(prefers-color-scheme: dark)" srcset="./Logo/LogoDark.svg">
   <img src="./Logo/Logo.svg" alt="Fig Logo" width="200">

src/Ast/Ast.hpp

@@ -11,13 +11,19 @@
 #include <Ast/Expr/IdentiExpr.hpp>
 #include <Ast/Expr/IndexExpr.hpp>
 #include <Ast/Expr/InfixExpr.hpp>
+#include <Ast/Expr/LambdaExpr.hpp>
 #include <Ast/Expr/LiteralExpr.hpp>
+#include <Ast/Expr/MemberExpr.hpp>
+#include <Ast/Expr/NewExpr.hpp>
 #include <Ast/Expr/PrefixExpr.hpp>
 
 #include <Ast/Stmt/ControlFlowStmts.hpp>
 #include <Ast/Stmt/ExprStmt.hpp>
 #include <Ast/Stmt/FnDefStmt.hpp>
 #include <Ast/Stmt/IfStmt.hpp>
+#include <Ast/Stmt/ImplStmt.hpp>
+#include <Ast/Stmt/InterfaceDefStmt.hpp>
+#include <Ast/Stmt/StructDefStmt.hpp>
 #include <Ast/Stmt/VarDecl.hpp>
 #include <Ast/Stmt/WhileStmt.hpp>
 #include <Ast/TypeExpr.hpp>

src/Ast/Base.hpp

@@ -29,7 +29,8 @@ namespace Fig
         IndexExpr,
         CallExpr,
         MemberExpr,     // obj.prop
-        ObjectInitExpr, // new Point{}
+        NewExpr, // new Point{}
+        LambdaExpr,
 
         /* Statements */
         ExprStmt,
@@ -48,7 +49,8 @@ namespace Fig
         /* Type Expressions */
         TypeExpr,
         NamedTypeExpr,
-        NullableTypeExpr
+        NullableTypeExpr,
+        FnTypeExpr,
     };
 
     struct AstNode

src/Ast/Expr/CallExpr.hpp

@@ -47,9 +47,10 @@ namespace Fig
             type = AstType::CallExpr;
         }
 
-        CallExpr(Expr *_callee, FnCallArgs _args) : callee(_callee), args(std::move(_args))
+        CallExpr(Expr *_callee, FnCallArgs _args, SourceLocation _location) : callee(_callee), args(std::move(_args))
         {
             type = AstType::CallExpr;
+            location = std::move(_location);
         }
 
         virtual String toString() const override

src/Ast/Expr/LambdaExpr.hpp

@@ -0,0 +1,70 @@
+/*!
+    @file src/Ast/Expr/LambdaExpr.hpp
+    @brief Lambda表达式定义
+*/
+
+#pragma once
+
+#include <Ast/Base.hpp>
+#include <Ast/Stmt/FnDefStmt.hpp>
+
+namespace Fig
+{
+    struct LambdaExpr final : public Expr
+    {
+        // func (params) [-> return type] ([=> expr] / [ {stmt} ])
+
+        DynArray<Param *> params;
+        TypeExpr         *returnType;
+        AstNode          *body; // expr/blockstmt
+        bool              isExprBody;
+
+        DynArray<UpvalueInfo> upvalues;
+
+        LambdaExpr()
+        {
+            type = AstType::LambdaExpr;
+        }
+
+        LambdaExpr(
+            DynArray<Param *> _params,
+            TypeExpr         *_returnType,
+            AstNode          *_body,
+            bool              _isExprBody,
+            SourceLocation    _location) :
+            params(std::move(_params)),
+            returnType(_returnType),
+            body(_body),
+            isExprBody(_isExprBody)
+        {
+            type     = AstType::LambdaExpr;
+            location = std::move(_location);
+        }
+
+        virtual String toString() const override
+        {
+            String specifying = "<LambdaExpr 'func (";
+            for (auto &p : params)
+            {
+                if (p != params.front())
+                {
+                    specifying += ", ";
+                }
+                specifying += p->toString();
+            }
+            if (isExprBody)
+            {
+                specifying += ") => ";
+                specifying += body->toString();
+            }
+            else
+            {
+                specifying += ") {";
+                specifying += body->toString();
+                specifying.push_back(U'}');
+            }
+            specifying += "'>";
+            return specifying;
+        }
+    };
+}; // namespace Fig

src/Ast/Expr/NewExpr.hpp

@@ -11,7 +11,7 @@
 
 namespace Fig
 {
-    struct ObjectInitExpr final : public Expr
+    struct NewExpr final : public Expr
     {
         struct Arg
         {
@@ -21,20 +21,20 @@ namespace Fig
         TypeExpr     *typeExpr;
         DynArray<Arg> args;
 
-        ObjectInitExpr()
+        NewExpr()
         {
-            type = AstType::ObjectInitExpr;
+            type = AstType::NewExpr;
         }
-        ObjectInitExpr(TypeExpr *_te, DynArray<Arg> _args, SourceLocation _loc) :
+        NewExpr(TypeExpr *_te, DynArray<Arg> _args, SourceLocation _loc) :
             typeExpr(_te), args(std::move(_args))
         {
-            type     = AstType::ObjectInitExpr;
+            type     = AstType::NewExpr;
             location = std::move(_loc);
         }
 
         virtual String toString() const override
         {
-            String res = "<ObjectInitExpr 'new " + typeExpr->toString() + "{";
+            String res = "<NewExpr 'new " + typeExpr->toString() + "{";
             for (size_t i = 0; i < args.size(); ++i)
             {
                 if (!args[i].name.empty())

src/Ast/Stmt/StructDefStmt.hpp

@@ -13,9 +13,12 @@ namespace Fig
     {
         struct Field
         {
+            bool isPublic;
+            bool typeInfer;
+
             String    name;
             TypeExpr *type;
-            bool      isPublic;
+            Expr *initExpr;
         };
         bool                  isPublic;
         String                name;

src/Ast/TypeExpr.hpp

@@ -64,4 +64,37 @@ namespace Fig
             return std::format("<NullableTypeExpr '{}?'>", inner->toString());
         }
     };
+
+    struct FnTypeExpr final : public TypeExpr
+    {
+        // func (paratypes...) -> return_type
+
+        DynArray<TypeExpr *> paraTypes;
+        TypeExpr *returnType;
+
+        FnTypeExpr(DynArray<TypeExpr *> _paraTypes, TypeExpr *_returnType) :
+            paraTypes(std::move(_paraTypes)), returnType(_returnType)
+        {
+            type = AstType::FnTypeExpr;
+        }
+
+        virtual String toString() const override
+        {
+            String detail = "<FnTypeExpr 'func (";
+
+            for (auto &pt : paraTypes)
+            {
+                if (pt != paraTypes.front())
+                {
+                    detail += ", ";
+                }
+                detail += pt->toString();
+            }
+            detail += ") -> ";
+            detail += returnType->toString();
+            detail += "'>";
+            
+            return detail;
+        }
+    };
 } // namespace Fig

src/Bytecode/Disassembler.cpp

@@ -75,6 +75,7 @@ namespace Fig
                 stream << std::format("  [{}] {}\n", i, proto->constants[i].ToString());
             }
         }
+        stream << "--- End Disassembly ---\n";
     }
 
     Disassembler::Format Disassembler::GetFormat(OpCode op)

src/Compiler/CompileTest.cpp

@@ -27,7 +27,11 @@ int main()
     }
 
     Lexer  lexer(source, filePath);
-    Parser parser(lexer, sm, filePath);
+
+    Diagnostics diagnostics;
+    Parser parser(lexer, sm, filePath, diagnostics);
+
+    diagnostics.EmitAll(sm);
 
     auto pRes = parser.Parse();
     if (!pRes)

src/Compiler/ExprCompiler.cpp

@@ -1,6 +1,6 @@
 /*!
     @file src/Compiler/ExprCompiler.cpp
-    @brief 表达式编译器实现：引入水位线(Watermark)与零拷贝复用机制
+    @brief 表达式编译器实现：水位线控制Register与零拷贝复用机制
 */
 
 #include <Ast/Expr/CallExpr.hpp>
@@ -12,7 +12,6 @@
 #include <limits>
 #include <system_error>
 
-
 namespace Fig
 {
     static Result<Value, Error> parsePhysicalNumber(const String &raw, const SourceLocation &loc)
@@ -20,46 +19,69 @@ namespace Fig
         char buffer[128];
         int  j       = 0;
         bool isFloat = false;
+
         for (size_t i = 0; i < raw.length() && j < 127; ++i)
         {
             char32_t c = raw[i];
             if (c == '_')
                 continue;
+
+            // 检查开头的无效字符
+            if (j == 0 && (c == '.' || c == 'e' || c == 'E'))
+                return std::unexpected(
+                    Error(ErrorType::SyntaxError, "unexpected leading character", "", loc));
+
             if (c == '.' || c == 'e' || c == 'E')
                 isFloat = true;
             buffer[j++] = (char) c;
         }
         buffer[j] = '\0';
 
+        // 检查16进制/2进制前缀
+        bool        isHexOrBin = false;
+        int         base       = 10;
+        const char *start      = buffer;
+
+        if (j >= 2 && buffer[0] == '0')
+        {
+            if (buffer[1] == 'x' || buffer[1] == 'X')
+            {
+                base = 16;
+                start += 2;
+                isHexOrBin = true;
+            }
+            else if (buffer[1] == 'b' || buffer[1] == 'B')
+            {
+                base = 2;
+                start += 2;
+                isHexOrBin = true;
+            }
+        }
+
         if (isFloat)
         {
+            // 如果既有浮点标记又是0x开头，可能是16进制浮点
+            auto fmt =
+                (isHexOrBin && base == 16) ? std::chars_format::hex : std::chars_format::general;
+
             double dVal;
-            auto [ptr, ec] = std::from_chars(buffer, buffer + j, dVal);
-            if (ec != std::errc())
-                return std::unexpected(Error(ErrorType::SyntaxError, "float overflow", "", loc));
+            auto [ptr, ec] = std::from_chars(start, buffer + j, dVal, fmt);
+
+            if (ec != std::errc() || ptr != buffer + j)
+                return std::unexpected(
+                    Error(ErrorType::SyntaxError, "invalid float literal", "", loc));
+
             return Value::FromDouble(dVal);
         }
-        else
+        else if (isHexOrBin)
         {
-            int         base  = 10;
-            const char *start = buffer;
-            if (j > 2 && buffer[0] == '0')
-            {
-                if (buffer[1] == 'x' || buffer[1] == 'X')
-                {
-                    base = 16;
-                    start += 2;
-                }
-                else if (buffer[1] == 'b' || buffer[1] == 'B')
-                {
-                    base = 2;
-                    start += 2;
-                }
-            }
+            // 16进制或2进制整数
             int64_t iVal;
             auto [ptr, ec] = std::from_chars(start, buffer + j, iVal, base);
-            if (ec != std::errc())
-                return std::unexpected(Error(ErrorType::SyntaxError, "integer overflow", "", loc));
+
+            if (ec != std::errc() || ptr != buffer + j)
+                return std::unexpected(
+                    Error(ErrorType::SyntaxError, "integer overflow or invalid literal", "", loc));
 
             if (iVal >= std::numeric_limits<int32_t>::min()
                 && iVal <= std::numeric_limits<int32_t>::max())
@@ -71,6 +93,27 @@ namespace Fig
                 return Value::FromDouble(static_cast<double>(iVal));
             }
         }
+        else
+        {
+            // 10进制数字，可能是整数或浮点数
+            double dVal;
+            auto [ptr, ec] = std::from_chars(start, buffer + j, dVal, std::chars_format::general);
+
+            if (ec != std::errc() || ptr != buffer + j)
+                return std::unexpected(
+                    Error(ErrorType::SyntaxError, "invalid number literal", "", loc));
+
+            // 检查是否是整数(没有小数部分且不超出int32范围)
+            if (dVal == std::floor(dVal) && dVal >= std::numeric_limits<int32_t>::min()
+                && dVal <= std::numeric_limits<int32_t>::max())
+            {
+                return Value::FromInt(static_cast<int32_t>(dVal));
+            }
+            else
+            {
+                return Value::FromDouble(dVal);
+            }
+        }
     }
 
     Result<Register, Error> Compiler::compileExpr(Expr *expr, Register target)
@@ -94,7 +137,9 @@ namespace Fig
                         parsePhysicalNumber(manager.GetSub(tok.index, tok.length), l->location);
                     if (!vRes)
                         return std::unexpected(vRes.error());
-                    emit(Op::iABx(OpCode::LoadK, r, static_cast<uint16_t>(addConstant(*vRes))), &l->location);
+                    emit(
+                        Op::iABx(OpCode::LoadK, r, static_cast<uint16_t>(addConstant(*vRes))),
+                        &l->location);
                 }
                 else if (tok.type == TokenType::LiteralString)
                 {
@@ -129,7 +174,9 @@ namespace Fig
                     // 仅在被强制指定目标（如参数装填）时发射搬运指令
                     if (target != sym->index)
                     {
-                        emit(Op::iABx(OpCode::Mov, target, static_cast<uint16_t>(sym->index)), &i->location);
+                        emit(
+                            Op::iABx(OpCode::Mov, target, static_cast<uint16_t>(sym->index)),
+                            &i->location);
                     }
                     return target;
                 }
@@ -137,7 +184,9 @@ namespace Fig
                 Register r = (target == NO_REG) ? *allocateReg(i->location) : target;
                 if (sym->location == SymbolLocation::Upvalue)
                 {
-                    emit(Op::iABC(OpCode::GetUpval, r, static_cast<uint8_t>(sym->index), 0), &i->location);
+                    emit(
+                        Op::iABC(OpCode::GetUpval, r, static_cast<uint8_t>(sym->index), 0),
+                        &i->location);
                 }
                 else if (sym->location == SymbolLocation::Global)
                 {
@@ -176,10 +225,12 @@ namespace Fig
                     {
                         isGlobalFastCall = true;
                         int protoIdx     = id->resolvedSymbol->index;
-                        emit(Op::iABC(OpCode::FastCall,
-                                 static_cast<uint8_t>(protoIdx),
-                                 baseReg,
-                                 static_cast<uint8_t>(c->args.args.size())),
+                        emit(
+                            Op::iABC(
+                                OpCode::FastCall,
+                                static_cast<uint8_t>(protoIdx),
+                                baseReg,
+                                static_cast<uint8_t>(c->args.args.size())),
                             &c->location);
                     }
                 }
@@ -193,10 +244,12 @@ namespace Fig
                         return std::unexpected(r_fn.error());
 
                     // 使用动态 Call 指令，RA 是指向堆闭包的寄存器
-                    emit(Op::iABC(OpCode::Call,
-                             *r_fn,
-                             baseReg,
-                             static_cast<uint8_t>(c->args.args.size())),
+                    emit(
+                        Op::iABC(
+                            OpCode::Call,
+                            *r_fn,
+                            baseReg,
+                            static_cast<uint8_t>(c->args.args.size())),
                         &c->location);
                 }
 
@@ -240,18 +293,25 @@ namespace Fig
                         Symbol *sym = lid->resolvedSymbol;
                         if (sym->location == SymbolLocation::Local)
                         {
-                            emit(Op::iABx(OpCode::Mov, static_cast<Register>(sym->index), *r_val), &lid->location);
+                            emit(
+                                Op::iABx(OpCode::Mov, static_cast<Register>(sym->index), *r_val),
+                                &lid->location);
                         }
                         else if (sym->location == SymbolLocation::Upvalue)
                         {
-                            emit(Op::iABC(
-                                OpCode::SetUpval, *r_val, static_cast<Register>(sym->index), 0), &lid->location);
+                            emit(
+                                Op::iABC(
+                                    OpCode::SetUpval, *r_val, static_cast<Register>(sym->index), 0),
+                                &lid->location);
                         }
                         else
                         {
-                            emit(Op::iABx(OpCode::SetGlobal,
-                                *r_val,
-                                static_cast<uint16_t>(getGlobalID(lid->name))), &lid->location);
+                            emit(
+                                Op::iABx(
+                                    OpCode::SetGlobal,
+                                    *r_val,
+                                    static_cast<uint16_t>(getGlobalID(lid->name))),
+                                &lid->location);
                         }
                     }
                     return r_val;
@@ -271,29 +331,61 @@ namespace Fig
                 OpCode op;
                 switch (in->op)
                 {
-                    case BinaryOperator::Add: op = isInt ? OpCode::IntFastAdd : OpCode::Add; break;
-                    case BinaryOperator::Subtract:
-                        op = isInt ? OpCode::IntFastSub : OpCode::Sub;
+                    case BinaryOperator::Add: {
+                        op = (isInt ? (OpCode::IntFastAdd) : (OpCode::Add));
                         break;
-                    case BinaryOperator::Multiply:
-                        op = isInt ? OpCode::IntFastMul : OpCode::Mul;
+                    }
+                    case BinaryOperator::Subtract: {
+                        op = (isInt ? (OpCode::IntFastSub) : (OpCode::Sub));
                         break;
-                    case BinaryOperator::Divide:
-                        op = isInt ? OpCode::IntFastDiv : OpCode::Div;
+                    }
+                    case BinaryOperator::Multiply: {
+                        op = (isInt ? (OpCode::IntFastMul) : (OpCode::Mul));
                         break;
-                    case BinaryOperator::Modulo: op = OpCode::Mod; break;
-                    case BinaryOperator::BitXor: op = OpCode::BitXor; break;
-                    case BinaryOperator::Equal: op = OpCode::Equal; break;
-                    case BinaryOperator::NotEqual: op = OpCode::NotEqual; break;
-                    case BinaryOperator::Greater: op = OpCode::Greater; break;
-                    case BinaryOperator::Less: op = OpCode::Less; break;
-                    case BinaryOperator::GreaterEqual: op = OpCode::GreaterEqual; break;
-                    case BinaryOperator::LessEqual: op = OpCode::LessEqual; break;
-                    default:
-                        return std::unexpected(Error(ErrorType::InternalError,
+                    }
+                    case BinaryOperator::Divide: {
+                        op = (isInt ? (OpCode::IntFastDiv) : (OpCode::Div));
+                        break;
+                    }
+                    case BinaryOperator::Modulo: {
+                        op = OpCode::Mod;
+                        break;
+                    }
+                    case BinaryOperator::BitXor: {
+                        op = OpCode::BitXor;
+                        break;
+                    }
+                    case BinaryOperator::Equal: {
+                        op = OpCode::Equal;
+                        break;
+                    }
+                    case BinaryOperator::NotEqual: {
+                        op = OpCode::NotEqual;
+                        break;
+                    }
+                    case BinaryOperator::Greater: {
+                        op = OpCode::Greater;
+                        break;
+                    }
+                    case BinaryOperator::Less: {
+                        op = OpCode::Less;
+                        break;
+                    }
+                    case BinaryOperator::GreaterEqual: {
+                        op = OpCode::GreaterEqual;
+                        break;
+                    }
+                    case BinaryOperator::LessEqual: {
+                        op = OpCode::LessEqual;
+                        break;
+                    }
+                    default: {
+                        return std::unexpected(Error(
+                            ErrorType::InternalError,
                             "unsupported binary operator",
                             "",
                             in->location));
+                    }
                 }
 
                 // 释放左右操作数产生的临时寄存器
@@ -318,6 +410,65 @@ namespace Fig
                 return r_d;
             }
 
+            case AstType::LambdaExpr: {
+                auto l = static_cast<LambdaExpr *>(expr);
+
+                Proto *proto = new Proto;
+                proto->name  = l->toString();
+
+                FuncState  fs(proto, current);
+                FuncState *old = current;
+                current        = &fs;
+
+                if (l->isExprBody)
+                {
+                    auto result = compileExpr(static_cast<Expr *>(l->body));
+                    if (!result)
+                    {
+                        return result;
+                    }
+
+                    emit(Op::iABC(OpCode::Return, *result, 0, 0), &l->location);
+                }
+                else
+                {
+                    auto result = compileStmt(static_cast<BlockStmt *>(l->body));
+                    if (!result)
+                    {
+                        return std::unexpected(result.error());
+                    }
+                    auto _r = allocateReg(l->body->location);
+                    if (!_r)
+                    {
+                        return _r;
+                    }
+
+                    Register r = *_r;
+                    emit(Op::iABC(OpCode::LoadNull, r, 0, 0), &l->body->location);
+                    emit(Op::iABC(OpCode::Return, r, 0, 0), &l->body->location);
+                }
+
+                int protoIndex = (int) module->protos.size();
+                module->protos.push_back(proto);
+
+                current = old;
+                if (target == NO_REG)
+                {
+                    auto _r = allocateReg(expr->location);
+                    if (!_r)
+                    {
+                        return _r;
+                    }
+                    emit(Op::iABx(OpCode::LoadFn, *_r, protoIndex), &l->body->location);
+                    return *_r;
+                }
+                else
+                {
+                    emit(Op::iABx(OpCode::LoadFn, target, protoIndex), &l->body->location);
+                }
+                return target;
+            }
+
             default: break;
         }
         return std::unexpected(

src/Error/Error.cpp

@@ -17,7 +17,8 @@ namespace Fig
         ost << color << msg << TerminalColors::Reset;
     }
 
-    void ColoredPrint(const char *color, const std::string &msg, std::ostream &ost = CoreIO::GetStdErr())
+    void
+    ColoredPrint(const char *color, const std::string &msg, std::ostream &ost = CoreIO::GetStdErr())
     {
         ost << color << msg << TerminalColors::Reset;
     }
@@ -30,7 +31,10 @@ namespace Fig
     std::string MultipleStr(const char *c, size_t n)
     {
         std::string buf;
-        for (size_t i = 0; i < n; ++i) { buf += c; }
+        for (size_t i = 0; i < n; ++i)
+        {
+            buf += c;
+        }
         return buf;
     }
 
@@ -40,6 +44,7 @@ namespace Fig
         switch (type)
         {
             case UnusedSymbol: return "UnusedSymbol";
+            case UnnecessarySemicolon: return "UnnecessarySemicolon";
 
             case MayBeNull: return "MaybeNull";
 
@@ -61,7 +66,8 @@ namespace Fig
             case TooManyConstants: return "TooManyConstants";
 
             case RegisterOverflow: return "RegisterOverflow";
-            case InternalError: return "InternalError";
+            case InternalError:
+                return "InternalError";
                 // default: return "Some one forgot to add case to `ErrorTypeToString`";
         }
         return "UnknownError";
@@ -69,10 +75,10 @@ namespace Fig
 
     void PrintSystemInfos()
     {
-        std::ostream &err = CoreIO::GetStdErr();
+        std::ostream     &err = CoreIO::GetStdErr();
         std::stringstream build_info;
-        build_info << "\r🌘 Fig v" << Core::VERSION << " on " << Core::PLATFORM << ' ' << Core::ARCH << '['
-                   << Core::COMPILER << ']' << '\n'
+        build_info << "\r🌘 Fig v" << Core::VERSION << " on " << Core::PLATFORM << ' ' << Core::ARCH
+                   << '[' << Core::COMPILER << ']' << '\n'
                    << "   Build Time: " << Core::COMPILE_TIME;
 
         const std::string &build_info_str = build_info.str();
@@ -83,35 +89,43 @@ namespace Fig
 
     void PrintErrorInfo(const Error &error, const SourceManager &srcManager)
     {
-        static constexpr const char *MinorColor = "\033[38;2;138;227;198m";
-        static constexpr const char *MediumColor = "\033[38;2;255;199;95m";
+        static constexpr const char *MinorColor    = "\033[38;2;138;227;198m";
+        static constexpr const char *MediumColor   = "\033[38;2;255;199;95m";
         static constexpr const char *CriticalColor = "\033[38;2;255;107;107m";
 
-        namespace TC = TerminalColors;
+        namespace TC      = TerminalColors;
         std::ostream &err = CoreIO::GetStdErr();
 
         uint8_t level = ErrorLevel(error.type);
         // const char *level_name = (level == 1 ? "Minor" : (level == 2 ? "Medium" : "Critical"));
-        const char *level_color = (level == 1 ? MinorColor : (level == 2 ? MediumColor : CriticalColor));
+        const char *level_color =
+            (level == 1 ? MinorColor : (level == 2 ? MediumColor : CriticalColor));
 
         err << "🔥 "
             << level_color
             //<< '(' << level_name << ')'
-            << 'E' << static_cast<int>(error.type) << TC::Reset << ": " << level_color << ErrorTypeToString(error.type)
-            << TC::Reset << '\n';
+            << 'E' << static_cast<int>(error.type) << TC::Reset << ": " << level_color
+            << ErrorTypeToString(error.type) << TC::Reset << '\n';
 
         const SourceLocation &location = error.location;
 
-        err << TC::DarkGray << "  ┌─> Fn " << TC::Cyan << '\'' << location.packageName << '.' << location.functionName
-            << '\'' << " " << location.fileName << " (" << TC::DarkGray << location.sp.line << ":" << location.sp.column
-            << TC::Cyan << ')' << TC::Reset << '\n';
+        err << TC::DarkGray << "  ┌─> Fn " << TC::Cyan << '\'' << location.packageName << '.'
+            << location.functionName << '\'' << " " << location.fileName << " (" << TC::DarkGray
+            << location.sp.line << ":" << location.sp.column << TC::Cyan << ')' << TC::Reset
+            << '\n';
         err << TC::DarkGray << "  │" << '\n' << "  │" << TC::Reset << '\n';
 
         // 尝试打印上3行 下2行
 
         int64_t line_start = location.sp.line - 3, line_end = location.sp.line + 2;
-        while (!srcManager.HasLine(line_end)) { --line_end; }
-        while (!srcManager.HasLine(line_start)) { ++line_start; }
+        while (!srcManager.HasLine(line_end))
+        {
+            --line_end;
+        }
+        while (!srcManager.HasLine(line_start))
+        {
+            ++line_start;
+        }
 
         const auto &getLineNumWidth = [](size_t l) {
             unsigned int cnt = 0;
@@ -127,30 +141,39 @@ namespace Fig
         {
             unsigned int offset = 2 + 2 + 1;
             //                     '  └─ '
-            if (i == location.sp.line) { err << TC::DarkGray << "  └─ " << TC::Reset; }
-            else if (i < location.sp.line) { err << TC::DarkGray << "  │  " << TC::Reset; }
+            if (i == location.sp.line)
+            {
+                err << TC::DarkGray << "  └─ " << TC::Reset;
+            }
+            else if (i < location.sp.line)
+            {
+                err << TC::DarkGray << "  │  " << TC::Reset;
+            }
             else
             {
                 err << MultipleStr(" ", offset);
             }
             unsigned int cur_line_number_width = getLineNumWidth(i);
 
-            err << MultipleStr(" ", max_line_number_width - cur_line_number_width) << TC::Yellow << i << TC::Reset;
+            err << MultipleStr(" ", max_line_number_width - cur_line_number_width) << TC::Yellow
+                << i << TC::Reset;
             err << " │ " << srcManager.GetLine(i) << '\n';
             if (i == location.sp.line)
             {
                 unsigned int error_col_offset = offset + 1 + max_line_number_width + 2;
-                err << MultipleStr(" ", error_col_offset) << MultipleStr(" ", location.sp.column - 1) << TC::LightGreen
+                err << MultipleStr(" ", error_col_offset)
+                    << MultipleStr(" ", location.sp.column - 1) << TC::LightGreen
                     << MultipleStr("^", location.sp.tok_length) << TC::Reset << '\n';
 
                 err << MultipleStr(" ", error_col_offset)
-                    << MultipleStr(" ", location.sp.column - 1 + location.sp.tok_length / 2) << "╰─ " << level_color
-                    << error.message << TC::Reset << "\n\n";
+                    << MultipleStr(" ", location.sp.column - 1 + location.sp.tok_length / 2)
+                    << "╰─ " << level_color << error.message << TC::Reset << "\n\n";
             }
         }
         err << "\n";
         err << "❓ " << TC::DarkGray << "Thrower: " << error.thrower_loc.function_name() << " ("
-            << error.thrower_loc.file_name() << ":" << error.thrower_loc.line() << ")" << TC::Reset << "\n";
+            << error.thrower_loc.file_name() << ":" << error.thrower_loc.line() << ")" << TC::Reset
+            << "\n";
         err << "💡 " << TC::Blue << "Suggestion: " << error.suggestion << TC::Reset;
         err << '\n';
     }
@@ -158,7 +181,7 @@ namespace Fig
     void ReportError(const Error &error, const SourceManager &srcManager)
     {
         assert(srcManager.read && "ReportError: srcManager doesn't read source");
-        assert(srcManager.HasLine(error.location.sp.line));
+        // assert(srcManager.HasLine(error.location.sp.line));
 
         PrintSystemInfos();
         PrintErrorInfo(error, srcManager);

src/Error/Error.hpp

@@ -24,6 +24,8 @@ namespace Fig
     {
         /* Minor */
         UnusedSymbol = 0,
+        UnnecessarySemicolon,
+        TrailingComma,
 
         /* Medium */
         MayBeNull = 1001,
@@ -51,7 +53,7 @@ namespace Fig
         TooManyLocals,
         TooManyConstants,
         
-        // --- 新增：编译器内部与VM约束 ---
+        // 编译器内部约束
         RegisterOverflow,
         InternalError,
     };

src/LSP/LSPServer.hpp

@@ -138,9 +138,12 @@ namespace Fig
             manager.LoadFromMemory(sourceCode);
 
             Lexer  lexer(sourceCode, "");
-            Parser parser(lexer, manager, "");
 
-            // 1. 语法检查拦截
+            Diagnostics diagnostics;
+
+            Parser parser(lexer, manager, "", diagnostics);
+
+            //  语法检查拦截
             auto parserResult = parser.Parse();
             if (!parserResult)
             {
@@ -148,6 +151,11 @@ namespace Fig
                 return;
             }
 
+            for (auto &diag : diagnostics.GetErrors())
+            {
+                SendDiagnostics(uri, &diag);
+            }
+
             Program *program = *parserResult;
 
             Analyzer analyzer(manager);
@@ -160,7 +168,12 @@ namespace Fig
                 return;
             }
 
-            // 3. 一切完美，发射空数组清空过去的错误红线
+            for (auto &diag : analyzer.GetDiagnostics().GetErrors())
+            {
+                SendDiagnostics(uri, &diag);
+            }
+
+            // 一切完美，发射空数组清空过去的错误红线
             SendDiagnostics(uri, nullptr);
         }
     };

src/Parser/ExprParser.cpp

@@ -14,7 +14,8 @@ namespace Fig
         StateProtector p(this, {State::ParsingLiteralExpr});
 
         const Token &literal_token = consumeToken();
-        LiteralExpr *node = arena.Allocate<LiteralExpr>(literal_token, makeSourceLocation(literal_token));
+        LiteralExpr *node =
+            arena.Allocate<LiteralExpr>(literal_token, makeSourceLocation(literal_token));
         return node;
     }
     Result<Expr *, Error> Parser::parseIdentiExpr() // 当前token为Identifier调用
@@ -65,8 +66,8 @@ namespace Fig
         return node;
     }
 
-    Result<Expr *, Error> Parser::parseIndexExpr(
-        Expr *base) // 由 parseExpression调用, 当前token为 `[`
+    Result<Expr *, Error>
+    Parser::parseIndexExpr(Expr *base) // 由 parseExpression调用, 当前token为 `[`
     {
         StateProtector p(this, {State::ParsingIndexExpr});
 
@@ -80,7 +81,8 @@ namespace Fig
 
         if (currentToken().type != TokenType::RightBracket) // `]`
         {
-            return std::unexpected(Error(ErrorType::SyntaxError,
+            return std::unexpected(Error(
+                ErrorType::SyntaxError,
                 "unclosed brackets",
                 "insert `]`",
                 makeSourceLocation(lbracket_token)));
@@ -91,12 +93,13 @@ namespace Fig
         return indexExpr;
     }
 
-    Result<Expr *, Error> Parser::parseCallExpr(
-        Expr *callee) // 由 parseExpression调用, 当前token为 `(`
+    Result<Expr *, Error>
+    Parser::parseCallExpr(Expr *callee) // 由 parseExpression调用, 当前token为 `(`
     {
         StateProtector p(this, {State::ParsingCallExpr});
 
         const Token &lparen_token = consumeToken(); // consume `(`
+        const SourceLocation &location = makeSourceLocation(lparen_token);
 
         FnCallArgs callArgs;
 
@@ -104,14 +107,15 @@ namespace Fig
         if (currentToken().type == TokenType::RightParen)
         {
             consumeToken(); // consume `)`
-            return arena.Allocate<CallExpr>(callee, callArgs);
+            return arena.Allocate<CallExpr>(callee, callArgs, location);
         }
 
         while (true)
         {
             if (currentToken().type == TokenType::EndOfFile)
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "fn call has unclosed parenthese",
                     "insert `)`",
                     makeSourceLocation(lparen_token)));
@@ -131,7 +135,8 @@ namespace Fig
 
             if (currentToken().type != TokenType::Comma)
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "expected `,` or `)` in argument list",
                     "insert `,`",
                     makeSourceLocation(currentToken())));
@@ -140,7 +145,186 @@ namespace Fig
             consumeToken(); // consume `,`
         }
 
-        return arena.Allocate<CallExpr>(callee, callArgs);
+        return arena.Allocate<CallExpr>(callee, callArgs, location);
+    }
+
+    Result<Expr *, Error> Parser::parseNewExpr()
+    {
+        // new type{...}
+        StateProtector p(this, {State::ParsingNewExpr});
+
+        SourceLocation location = makeSourceLocation(consumeToken()); // consume `new`
+
+        SET_STOP_AT(TokenType::LeftBrace); // {
+        auto type_result = parseTypeExpr();
+        if (!type_result)
+        {
+            return std::unexpected(type_result.error());
+        }
+        TypeExpr *type = *type_result;
+
+        if (!match(TokenType::LeftBrace))
+        {
+            return std::unexpected(makeUnexpectTokenError("NewExpr", "lbrace {", currentToken()));
+        }
+
+        const Token &lb_token = prevToken();
+
+        /*
+            Positional:
+                new Point{1, 2}
+            Named:
+                new Point{x = 1, y = 2}
+        */
+
+        DynArray<NewExpr::Arg> args;
+
+        while (true)
+        {
+            if (isEOF)
+            {
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
+                    "unclosed `{` in new expr",
+                    "insert '}'",
+                    makeSourceLocation(lb_token)
+                ));
+            }
+            if (args.empty() && match(TokenType::RightBrace)) // 空参
+            {
+                break;
+            }
+
+            if (currentToken().isIdentifier() && peekToken().type == TokenType::Assign)
+            {
+                const Token &name_token = consumeToken();
+                const String &name = srcManager.GetSub(name_token.index, name_token.length);
+                consumeToken(); // consume `=`
+
+                SET_STOP_AT(TokenType::Comma, TokenType::RightBrace); // , / }
+                auto result = parseExpression();
+                if (!result)
+                {
+                    return result;
+                }
+
+                args.push_back(NewExpr::Arg{
+                    name,
+                    *result
+                });
+            }
+            else 
+            {
+                SET_STOP_AT(TokenType::Comma, TokenType::RightBrace); // , / }
+                auto result = parseExpression();
+                if (!result)
+                {
+                    return result;
+                }
+
+                args.push_back(NewExpr::Arg{
+                    .value = *result
+                });
+            }
+            
+
+            if (match(TokenType::Comma))
+            {
+                continue;
+            }
+
+            if (match(TokenType::RightBrace))
+            {
+                break;
+            }
+        }
+
+        NewExpr *newExpr = arena.Allocate<NewExpr>(type, args, location);
+        return newExpr;
+    }
+
+    Result<Expr *, Error> Parser::parseLambdaExpr()
+    {
+        StateProtector p(this, {State::ParsingLambdaExpr});
+
+        SourceLocation location = makeSourceLocation(consumeToken()); // consume `func`
+
+        if (currentToken().isIdentifier())
+        {
+            return std::unexpected(Error(
+                ErrorType::SyntaxError,
+                "lambda expression should not have a name",
+                "remove the name",
+                makeSourceLocation(currentToken())));
+        }
+
+        if (currentToken().type != TokenType::LeftParen)
+        {
+            return std::unexpected(
+                makeUnexpectTokenError("fn def stmt", "lparen '('", currentToken()));
+        }
+
+        DynArray<Param *> params;
+
+        auto paraResult = parseFnParams();
+        if (!paraResult)
+        {
+            return std::unexpected(paraResult.error());
+        }
+        params = *paraResult;
+
+        TypeExpr *returnType = nullptr;
+        Token     rightArrowToken;
+        if (match(TokenType::RightArrow)) // ->
+        {
+            rightArrowToken = consumeToken();
+
+            auto result = parseTypeExpr();
+            if (!result)
+            {
+                return std::unexpected(result.error());
+            }
+            returnType = *result;
+        }
+
+        if (match(TokenType::DoubleArrow)) // =>
+        {
+            if (returnType)
+            {
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
+                    "use of expr body but specified return type in lambda expr",
+                    "remove `-> ...`",
+                    makeSourceLocation(rightArrowToken)));
+            }
+            auto result = parseExpression();
+            if (!result)
+            {
+                return result;
+            }
+
+            Expr       *expr = *result;
+            LambdaExpr *lambda =
+                arena.Allocate<LambdaExpr>(params, returnType, expr, true, location);
+            return lambda;
+        }
+        else if (currentToken().type == TokenType::LeftBrace)
+        {
+            auto result = parseBlockStmt();
+            if (!result)
+            {
+                return std::unexpected(result.error());
+            }
+
+            LambdaExpr *lambda =
+                arena.Allocate<LambdaExpr>(params, returnType, *result, false, location);
+            return lambda;
+        }
+        else
+        {
+            return std::unexpected(
+                makeUnexpectTokenError("LambdaExpr", "darrow => / lbrace {", currentToken()));
+        }
     }
 
     Result<Expr *, Error> Parser::parseExpression(BindingPower rbp)
@@ -186,17 +370,39 @@ namespace Fig
             const Token &rparen_token = consumeToken(); // consume `)`
             if (rparen_token.type != TokenType::RightParen)
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "unclosed parenthese",
                     "insert `)`",
                     makeSourceLocation(lparen_token)));
             }
             lhs = *expr_result;
         }
+        else if (token.type == TokenType::Function)
+        {
+            auto result = parseLambdaExpr();
+            if (!result)
+            {
+                return result;
+            }
+
+            lhs = *result;
+        }
+        else if (token.type == TokenType::New)
+        {
+            auto result = parseNewExpr();
+            if (!result)
+            {
+                return result;
+            }
+
+            lhs = *result;
+        }
 
         if (!lhs)
         {
-            return std::unexpected(Error(ErrorType::ExpectedExpression,
+            return std::unexpected(Error(
+                ErrorType::ExpectedExpression,
                 "expected expression",
                 "insert expressions",
                 makeSourceLocation(prevToken())));
@@ -253,10 +459,11 @@ namespace Fig
             }
             else
             {
-                return std::unexpected(Error(ErrorType::ExpectedExpression,
-                    "expression unexpectedly ended",
-                    "insert expressions",
-                    makeSourceLocation(token)));
+                // return std::unexpected(Error(ErrorType::ExpectedExpression,
+                //     "expression unexpectedly ended",
+                //     "insert expressions",
+                //     makeSourceLocation(token)));
+                return lhs;
             }
         }
         return lhs;

src/Parser/Parser.hpp

@@ -9,6 +9,7 @@
 
 #include <Ast/Ast.hpp>
 #include <Deps/Deps.hpp>
+#include <Error/Diagnostics.hpp>
 #include <Error/Error.hpp>
 #include <Lexer/Lexer.hpp>
 #include <Token/Token.hpp>
@@ -33,6 +34,8 @@ namespace Fig
         String fileName;
         bool   isEOF = false;
 
+        Diagnostics &diagnostics;
+
         // 惰性获取下一个 Token，跳过注释
         Token nextToken()
         {
@@ -116,12 +119,16 @@ namespace Fig
             enum StateType : std::uint8_t
             {
                 Standby,
+
                 ParsingLiteralExpr,
                 ParsingIdentiExpr,
                 ParsingInfixExpr,
                 ParsingPrefixExpr,
                 ParsingIndexExpr,
                 ParsingCallExpr,
+                ParsingLambdaExpr,
+                ParsingNewExpr,
+
                 ParsingVarDecl,
                 ParsingIf,
                 ParsingWhile,
@@ -129,7 +136,11 @@ namespace Fig
                 ParsingReturn,
                 ParsingBreak,
                 ParsingContinue,
+                ParsingStructDef,
+
+                ParsingTypeParameters,
                 ParsingNamedTypeExpr,
+                ParsingFnTypeExpr,
             } type                               = StateType::Standby;
             std::unordered_set<TokenType> stopAt = {};
         };
@@ -137,7 +148,8 @@ namespace Fig
     private:
         const std::unordered_set<TokenType> &getBaseTerminators()
         {
-            static const std::unordered_set<TokenType> baseTerminators = {TokenType::Semicolon,
+            static const std::unordered_set<TokenType> baseTerminators{
+                TokenType::Semicolon,
                 TokenType::RightParen,
                 TokenType::RightBracket,
                 TokenType::RightBrace,
@@ -200,34 +212,58 @@ namespace Fig
         SourceLocation makeSourceLocation(const Token &tok)
         {
             auto [line, column] = srcManager.GetLineColumn(tok.index);
-            // 物理防爆盾：防止因解析错位导致的异常列号引起终端 OOM
+            // 防止因解析错位导致的异常列号引起终端 OOM
             if (column > 5000)
                 column = 1;
-            return SourceLocation(SourcePosition(line, column, tok.length),
+            return SourceLocation(
+                SourcePosition(line, column, tok.length),
                 fileName,
                 "[internal parser]",
                 magic_enum::enum_name(currentState().type).data());
         }
 
-        inline Error makeUnexpectTokenError(const String &stmt, const String &exp, const Token &got)
+        inline Error makeUnexpectTokenError(
+            const String        &stmt,
+            const String        &exp,
+            const Token         &got,
+            std::source_location th_loc = std::source_location::current())
         {
-            return Error(ErrorType::SyntaxError,
+            return Error(
+                ErrorType::SyntaxError,
                 std::format(
                     "expect '{}' in {}, got `{}`", exp, stmt, magic_enum::enum_name(got.type)),
                 "none",
-                makeSourceLocation(got));
+                makeSourceLocation(got),
+                th_loc);
         }
 
-        inline Error makeExpectSemicolonError()
+        inline Error
+        makeExpectSemicolonError(std::source_location th_loc = std::source_location::current())
         {
-            return Error(ErrorType::SyntaxError,
+            return Error(
+                ErrorType::SyntaxError,
                 "expect ';' after statement",
                 "insert ';'",
-                makeSourceLocation(currentToken()));
+                makeSourceLocation(currentToken()),
+                th_loc);
         }
 
+        inline Error makeExpectSemicolonError(
+            const Token &token, std::source_location th_loc = std::source_location::current())
+        {
+            return Error(
+                ErrorType::SyntaxError,
+                "expect ';' after statement",
+                "insert ';'",
+                makeSourceLocation(token),
+                th_loc);
+        }
+
+        Result<decltype(StructDefStmt::typeParameters), Error> parseTypeParameters();
+        
         Result<TypeExpr *, Error> parseTypeExpr();
         Result<TypeExpr *, Error> parseNamedTypeExpr();
+        Result<TypeExpr *, Error> parseFnTypeExpr();
 
         Result<Expr *, Error> parseExpression(BindingPower = 0);
         Result<Expr *, Error> parseLiteralExpr();
@@ -237,6 +273,7 @@ namespace Fig
         Result<Expr *, Error> parseIndexExpr(Expr *);
         Result<Expr *, Error> parseCallExpr(Expr *);
         Result<Expr *, Error> parseNewExpr();
+        Result<Expr *, Error> parseLambdaExpr();
 
         Result<BlockStmt *, Error>       parseBlockStmt();
         Result<VarDecl *, Error>         parseVarDecl(bool);
@@ -253,8 +290,8 @@ namespace Fig
         Result<Stmt *, Error> parseStatement();
 
     public:
-        Parser(Lexer &_lexer, SourceManager &_src, String _file) :
-            lexer(_lexer), srcManager(_src), fileName(std::move(_file))
+        Parser(Lexer &_lexer, SourceManager &_src, String _file, Diagnostics &_diagnostics) :
+            lexer(_lexer), srcManager(_src), fileName(std::move(_file)), diagnostics(_diagnostics)
         {
             pushState(State());
         }

src/Parser/ParserTest.cpp

@@ -18,13 +18,19 @@ int main()
     }
 
     Lexer  lexer(source, fileName);
-    Parser parser(lexer, srcManager, fileName);
+
+    Diagnostics diagnostics;
+    Parser parser(lexer, srcManager, fileName, diagnostics);
+
     auto   result = parser.Parse();
     if (!result)
     {
         ReportError(result.error(), srcManager);
         return 1;
     }
+
+    diagnostics.EmitAll(srcManager);
+
     Program *program = *result;
     for (Stmt *stmt : program->nodes)
     {

src/Parser/StmtParser.cpp

@@ -17,7 +17,8 @@ namespace Fig
         {
             if (isEOF)
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "unclosed braces in block stmt",
                     "insert '}'",
                     location));
@@ -75,7 +76,8 @@ namespace Fig
         {
             if (typeSpeicifer)
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "used type infer but specifying the type",
                     "change `:=` to '='",
                     makeSourceLocation(prevToken())));
@@ -115,7 +117,8 @@ namespace Fig
             }
             if (!match(TokenType::RightParen))
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "unclosed parenthese in if condition",
                     "insert `)`",
                     makeSourceLocation(lpToken)));
@@ -155,7 +158,8 @@ namespace Fig
             {
                 if (alternate)
                 {
-                    return std::unexpected(Error(ErrorType::SyntaxError,
+                    return std::unexpected(Error(
+                        ErrorType::SyntaxError,
                         "else if after else",
                         "remove else if",
                         elseLocation));
@@ -175,7 +179,8 @@ namespace Fig
                     }
                     if (!match(TokenType::RightParen))
                     {
-                        return std::unexpected(Error(ErrorType::SyntaxError,
+                        return std::unexpected(Error(
+                            ErrorType::SyntaxError,
                             "unclosed parenthese in if condition",
                             "insert `)`",
                             makeSourceLocation(lpToken)));
@@ -210,7 +215,8 @@ namespace Fig
             {
                 if (alternate)
                 {
-                    return std::unexpected(Error(ErrorType::SyntaxError,
+                    return std::unexpected(Error(
+                        ErrorType::SyntaxError,
                         "duplicate else in if stmt",
                         "remove it",
                         elseLocation));
@@ -252,7 +258,8 @@ namespace Fig
 
             if (!match(TokenType::RightParen))
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "unclosed parenthese in while condition",
                     "insert ')'",
                     makeSourceLocation(lpToken)));
@@ -289,8 +296,6 @@ namespace Fig
 
     Result<DynArray<Param *>, Error> Parser::parseFnParams()
     {
-        StateProtector p(this, {State::ParsingFnDefStmt});
-
         const Token      &lpToken = consumeToken();
         DynArray<Param *> params;
 
@@ -298,7 +303,8 @@ namespace Fig
         {
             if (isEOF)
             {
-                return std::unexpected(Error(ErrorType::SyntaxError,
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
                     "unclosed parenthese in function parameters",
                     "insert ')'",
                     makeSourceLocation(lpToken)));
@@ -353,6 +359,7 @@ namespace Fig
 
     Result<FnDefStmt *, Error> Parser::parseFnDefStmt(bool isPublic)
     {
+        StateProtector p(this, {State::ParsingFnDefStmt});
         SourceLocation location = makeSourceLocation(consumeToken());
 
         if (!currentToken().isIdentifier())
@@ -389,19 +396,49 @@ namespace Fig
             returnType = *result;
         }
 
-        if (currentToken().type != TokenType::LeftBrace)
+        BlockStmt *body = nullptr;
+        if (match(TokenType::DoubleArrow)) // =>
+        {
+            auto result = parseExpression();
+            if (!result)
+            {
+                return std::unexpected(result.error());
+            }
+
+            // if (!match(TokenType::Semicolon)) // ;
+            // {
+            //     return std::unexpected(makeExpectSemicolonError(prevToken()));
+            // }
+
+            if (match(TokenType::Semicolon))
+            {
+                diagnostics.Report(Error(
+                    ErrorType::UnnecessarySemicolon,
+                    "`;` is unnecessary in this context",
+                    "try remove `;`",
+                    makeSourceLocation(prevToken())));
+            }
+
+            Expr       *expr       = *result;
+            ReturnStmt *returnStmt = arena.Allocate<ReturnStmt>(expr, expr->location);
+
+            body = arena.Allocate<BlockStmt>();
+            body->nodes.push_back(returnStmt);
+        }
+        else if (currentToken().type == TokenType::LeftBrace)
+        {
+            auto bodyResult = parseBlockStmt();
+            if (!bodyResult)
+            {
+                return std::unexpected(bodyResult.error());
+            }
+            body = *bodyResult;
+        }
+        else
         {
             return std::unexpected(
-                makeUnexpectTokenError("fn def stmt", "function body '{'", currentToken()));
+                makeUnexpectTokenError("fn def stmt", "function body '=>' / '{'", currentToken()));
         }
-        BlockStmt *body       = nullptr;
-        auto       bodyResult = parseBlockStmt();
-
-        if (!bodyResult)
-        {
-            return std::unexpected(bodyResult.error());
-        }
-        body = *bodyResult;
 
         FnDefStmt *fnDef =
             arena.Allocate<FnDefStmt>(isPublic, name, params, returnType, body, location);
@@ -429,6 +466,127 @@ namespace Fig
         return returnStmt;
     }
 
+    Result<Stmt *, Error> Parser::parseStructDef(bool isPublic)
+    {
+        StateProtector p(this, {State::ParsingStructDef});
+
+        SourceLocation location = makeSourceLocation(consumeToken()); // consume `struct`
+        if (!currentToken().isIdentifier())
+        {
+            return std::unexpected(
+                makeUnexpectTokenError("StructDef", "struct name", currentToken()));
+        }
+
+        const Token  &name_tok = consumeToken(); // consume name
+        const String &name     = srcManager.GetSub(name_tok.index, name_tok.length);
+
+        StructDefStmt *stDef = arena.Allocate<StructDefStmt>();
+
+        if (currentToken().type == TokenType::Less) // <
+        {
+            auto result = parseTypeParameters();
+            if (!result)
+            {
+                return std::unexpected(result.error());
+            }
+
+            stDef->typeParameters = *result;
+        }
+
+        if (!match(TokenType::LeftBrace))
+        {
+            return std::unexpected(
+                makeUnexpectTokenError("StructDef", "lbrace '{'", currentToken()));
+        }
+
+        const Token &lb_tok = prevToken(); // `{`
+
+        while (true)
+        {
+            if (isEOF)
+            {
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
+                    "unclosed braces in struct def",
+                    "insert '}'",
+                    makeSourceLocation(lb_tok)));
+            }
+            if (match(TokenType::RightBrace))
+            {
+                break;
+            }
+
+            // (public) field_name (: Type) (= expr) / (:= expr)
+
+            bool isPublic = match(TokenType::Public);
+            if (currentToken().isIdentifier())
+            {
+                const Token  &name_tok   = consumeToken();
+                const String &field_name = srcManager.GetSub(name_tok.index, name_tok.length);
+
+                if (match(TokenType::Walrus)) // :=
+                {
+                    auto result = parseExpression();
+                    if (!result)
+                    {
+                        return std::unexpected(result.error());
+                    }
+
+                    stDef->fields.push_back(
+                        StructDefStmt::Field{isPublic, true, field_name, nullptr, *result});
+                }
+                else
+                {
+                    TypeExpr *type     = nullptr;
+                    Expr     *initExpr = nullptr;
+
+                    if (match(TokenType::Colon)) // :
+                    {
+                        auto result = parseTypeExpr();
+                        if (!result)
+                        {
+                            return std::unexpected(result.error());
+                        }
+                        type = *result;
+                    }
+
+                    if (match(TokenType::Assign))
+                    {
+                        auto result = parseExpression();
+                        if (!result)
+                        {
+                            return std::unexpected(result.error());
+                        }
+                        initExpr = *result;
+                    }
+                    stDef->fields.push_back(
+                        StructDefStmt::Field{isPublic, false, field_name, type, initExpr});
+                }
+                if (!match(TokenType::Semicolon))
+                {
+                    return std::unexpected(makeExpectSemicolonError());
+                }
+            }
+            else if (currentToken().type == TokenType::Function)
+            {
+                auto result = parseFnDefStmt(isPublic);
+                if (!result)
+                {
+                    return result;
+                }
+
+                stDef->methods.push_back(*result);
+            }
+            else
+            {
+                return std::unexpected(
+                    makeUnexpectTokenError("StructDef", "field or method", currentToken()));
+            }
+        }
+
+        return stDef;
+    }
+
     Result<Stmt *, Error> Parser::parseStatement()
     {
         StateProtector p(this, {State::Standby});
@@ -446,6 +604,11 @@ namespace Fig
                 return parseFnDefStmt(true);
             }
 
+            if (currentToken().type == TokenType::Struct)
+            {
+                return parseStructDef(true);
+            }
+
             return std::unexpected(
                 makeUnexpectTokenError("public", "var/const/func/struct", currentToken()));
         }
@@ -470,11 +633,16 @@ namespace Fig
             return parseWhileStmt();
         }
 
-        if (currentToken().type == TokenType::Function)
+        if (currentToken().type == TokenType::Function && peekToken().isIdentifier())
         {
             return parseFnDefStmt(false);
         }
 
+        if (currentToken().type == TokenType::Struct)
+        {
+            return parseStructDef(false);
+        }
+
         if (currentToken().type == TokenType::Return)
         {
             return parseReturnStmt();
@@ -507,6 +675,15 @@ namespace Fig
             return nullptr;
         }
 
+        if (currentToken().type == TokenType::Semicolon)
+        {
+            return std::unexpected(Error(
+                ErrorType::SyntaxError,
+                "null statement is not allowed here",
+                "remove `;`",
+                makeSourceLocation(currentToken())));
+        }
+
         const auto &expr_result = parseExpression();
         if (!expr_result)
         {

src/Parser/TypeExprParser.cpp

@@ -9,6 +9,46 @@
 
 namespace Fig
 {
+    Result<decltype(StructDefStmt::typeParameters), Error> Parser::parseTypeParameters()
+    {
+        StateProtector                          p(this, {State::ParsingTypeParameters});
+        decltype(StructDefStmt::typeParameters) tp;
+
+        const Token &lab = consumeToken(); // consume `<`
+
+        while (true)
+        {
+            if (isEOF)
+            {
+                return std::unexpected(Error(
+                    ErrorType::SyntaxError,
+                    "unclosed `<` in type parameters",
+                    "insert '>'",
+                    makeSourceLocation(lab)));
+            }
+            if (match(TokenType::Greater)) // >
+            {
+                break;
+            }
+            if (!currentToken().isIdentifier())
+            {
+                return std::unexpected(
+                    makeUnexpectTokenError("TypeParams", "tp name", currentToken()));
+            }
+
+            const Token  &name_tok = consumeToken();
+            const String &name     = srcManager.GetSub(name_tok.index, name_tok.length);
+            tp.push_back(name);
+
+            if (!match(TokenType::Comma))
+            {
+                return std::unexpected(makeUnexpectTokenError(
+                    "TypeParams", "comma or type parameter", currentToken()));
+            }
+        }
+        return tp;
+    }
+
     // 解析基础命名类型与泛型: List<Int>
     Result<TypeExpr *, Error> Parser::parseNamedTypeExpr()
     {
@@ -25,9 +65,11 @@ namespace Fig
             if (match(TokenType::Dot))
             {
                 if (!currentToken().isIdentifier())
-                    return std::unexpected(makeUnexpectTokenError("Type", "identifier", currentToken()));
+                    return std::unexpected(
+                        makeUnexpectTokenError("Type", "identifier", currentToken()));
             }
-            else break;
+            else
+                break;
         }
 
         DynArray<TypeExpr *> arguments;
@@ -36,38 +78,109 @@ namespace Fig
             while (true)
             {
                 auto result = parseTypeExpr();
-                if (!result) return std::unexpected(result.error());
+                if (!result)
+                    return std::unexpected(result.error());
                 arguments.push_back(*result);
 
-                if (match(TokenType::Greater)) break; // `>`
+                if (match(TokenType::Greater))
+                    break; // `>`
                 if (!match(TokenType::Comma))
-                    return std::unexpected(makeUnexpectTokenError("TypeArgs", "'>' or ','", currentToken()));
+                    return std::unexpected(
+                        makeUnexpectTokenError("TypeArgs", "'>' or ','", currentToken()));
             }
         }
 
         return arena.Allocate<NamedTypeExpr>(path, arguments, location);
     }
 
+    Result<TypeExpr *, Error> Parser::parseFnTypeExpr()
+    {
+        StateProtector p(this, {State::ParsingFnTypeExpr});
+        SourceLocation location = makeSourceLocation(consumeToken()); // consume `func`
+        if (!match(TokenType::LeftParen))                             // `(`
+        {
+            return std::unexpected(
+                makeUnexpectTokenError("FnTypeExpr", "lparen (", currentToken()));
+        }
+
+        DynArray<TypeExpr *> paraTypes;
+
+        while (true)
+        {
+            auto result = parseTypeExpr();
+            if (!result)
+            {
+                return result;
+            }
+            paraTypes.push_back(*result);
+
+            if (match(TokenType::RightParen))
+            {
+                break;
+            }
+            else if (isEOF)
+            {
+                return std::unexpected(
+                    makeUnexpectTokenError("FnTypeExpr", "rparen )", currentToken()));
+            }
+            if (!match(TokenType::Comma))
+            {
+                return std::unexpected(
+                    makeUnexpectTokenError("FnTypeExpr", "comma ,", currentToken()));
+            }
+        }
+
+        TypeExpr *returnType = nullptr;
+
+        if (match(TokenType::RightArrow)) // ->
+        {
+            auto result = parseTypeExpr();
+            if (!result)
+            {
+                return result;
+            }
+            returnType = *result;
+        }
+
+        FnTypeExpr *fnTypeExpr = arena.Allocate<FnTypeExpr>(paraTypes, returnType);
+        return fnTypeExpr;
+    }
+
     // 解析主入口: 处理 `?` 后缀
     Result<TypeExpr *, Error> Parser::parseTypeExpr()
     {
         TypeExpr *base = nullptr;
 
-        // 目前只支持命名类型 (以后可以加函数类型 (Int)->Int)
         if (currentToken().isIdentifier())
         {
-            auto res = parseNamedTypeExpr();
-            if (!res) return std::unexpected(res.error());
-            base = *res;
+            auto result = parseNamedTypeExpr();
+            if (!result)
+            {
+                return result;
+            }
+            base = *result;
         }
-        else return std::unexpected(makeUnexpectTokenError("TypeExpr", "name", currentToken()));
-
-        // 空安全处理: Int?? 也可以，但 Analyzer 会规范化它
-        while (match(TokenType::Question))
+        else if (currentToken().type == TokenType::Function)
         {
-            base = arena.Allocate<NullableTypeExpr>(base, makeSourceLocation(prevToken()));
+            auto result = parseFnTypeExpr();
+            if (!result)
+            {
+                return result;
+            }
+            base = *result;
+        }
+        else
+        {
+            return std::unexpected(makeUnexpectTokenError("TypeExpr", "name", currentToken()));
+        }
+
+        // type (?)
+        if (currentToken().type == TokenType::Question) // ?
+        {
+            base = arena.Allocate<NullableTypeExpr>(
+                base, makeSourceLocation(consumeToken())); // consume `?`
         }
 
         return base;
     }
-}
+} // namespace Fig

src/Repl/Repl.hpp

@@ -38,15 +38,18 @@ namespace Fig
 
         void PrintInfo()
         {
-            out << std::format("Fig {}, copyright (c) 2025-2026 PuqiAR, under the {} License\n",
+            out << std::format(
+                "Fig {}, copyright (c) 2025-2026 PuqiAR, under the {} License\n",
                 Core::VERSION,
                 Core::LICENSE);
-            out << std::format("Build time: {} [{} x{} on {}]\n",
+            out << std::format(
+                "Build time: {} [{} x{} on {}]\n",
                 Core::COMPILE_TIME,
                 Core::COMPILER,
                 Core::ARCH,
                 Core::PLATFORM);
             out << "Type '#exit' to exit, '#clear' to clear the the screen, '#license' to see the full license, '#logo' to see a GREAT logo\n";
+            out << '\n';
         }
 
         void ClearConsole()
@@ -146,17 +149,58 @@ namespace Fig
                 ++rline;
             }
         }
+        // void PrintError(const Error &error, const String &source)
+        // {
+        //     err << "Oops! An error occurred!";
+        //     err << "🔥 " << 'E' << static_cast<int>(error.type) << ": " << error.message << '\n';
+        //     err << "Line " << rline << ", `" << source << "`\n";
+        //     err << "Suggestion: " << error.suggestion << '\n';
+        //     err << std::format(
+        //         "Thrower: {} ({}:{}:{})\n",
+        //         error.thrower_loc.function_name(),
+        //         error.thrower_loc.file_name(),
+        //         error.thrower_loc.line(),
+        //         error.thrower_loc.column());
+        // }
+
         void PrintError(const Error &error, const String &source)
         {
-            err << "Oops! An error occurred!";
-            err << "🔥 " << 'E' << static_cast<int>(error.type) << ": " << error.message << '\n';
-            err << "Line " << rline << ", `" << source << "`\n";
-            err << "Suggestion: " << error.suggestion << '\n';
-            err << std::format("Thrower: {} ({}:{}:{})\n",
-                error.thrower_loc.function_name(),
-                error.thrower_loc.file_name(),
-                error.thrower_loc.line(),
-                error.thrower_loc.column());
+            static constexpr const char *MinorColor    = "\033[38;2;138;227;198m";
+            static constexpr const char *MediumColor   = "\033[38;2;255;199;95m";
+            static constexpr const char *CriticalColor = "\033[38;2;255;107;107m";
+
+            namespace TC      = TerminalColors;
+            std::ostream &err = CoreIO::GetStdErr();
+
+            uint8_t level = ErrorLevel(error.type);
+            // const char *level_name = (level == 1 ? "Minor" : (level == 2 ? "Medium" :
+            // "Critical"));
+            const char *const &level_color =
+                (level == 1 ? MinorColor : (level == 2 ? MediumColor : CriticalColor));
+
+            err << "\n";
+            err << "🔥 "
+                << level_color
+                //<< '(' << level_name << ')'
+                << 'E' << static_cast<int>(error.type) << TC::Reset << ": " << level_color
+                << ErrorTypeToString(error.type) << TC::Reset << '\n';
+
+            const SourceLocation &location = error.location;
+
+            err << TC::DarkGray << "  ┌─> Fn " << TC::Cyan << '\'' << location.packageName << '.'
+                << location.functionName << '\'' << " " << location.fileName << " (" << TC::DarkGray
+                << location.sp.line << ":" << location.sp.column << TC::Cyan << ')' << TC::Reset
+                << '\n';
+            err << TC::DarkGray << "  │" << '\n' << "  │" << TC::Reset << '\n';
+            err << TC::DarkGray << "  └─ " << TC::Reset;
+            err << source << "\n";
+
+            err << "\n";
+            err << "❓ " << TC::DarkGray << "Thrower: " << error.thrower_loc.function_name() << " ("
+                << error.thrower_loc.file_name() << ":" << error.thrower_loc.line() << ")"
+                << TC::Reset << "\n";
+            err << "💡 " << TC::Blue << "Suggestion: " << error.suggestion << TC::Reset;
+            err << '\n';
         }
 
         unsigned int Start() // exit code: unsigned int
@@ -208,8 +252,11 @@ namespace Fig
 
                 String source(buf);
 
-                Lexer  lexer(buf, fileName);
-                Parser parser(lexer, manager, fileName);
+                Lexer lexer(buf, fileName);
+
+                Diagnostics diagnostics;
+
+                Parser parser(lexer, manager, fileName, diagnostics);
 
                 auto _program = parser.Parse();
                 if (!_program)
@@ -223,13 +270,15 @@ namespace Fig
                 Analyzer analyzer(manager);
                 auto     result = analyzer.Analyze(program);
 
+                analyzer.GetDiagnostics().EmitAll(manager);
+
                 if (!result)
                 {
                     PrintError(result.error(), source);
                     continue;
                 }
 
-                Compiler compiler(manager, analyzer.GetDiagnostics());
+                Compiler compiler(manager, diagnostics);
 
                 auto compile_result = compiler.Compile(program);
                 if (!compile_result)
@@ -238,6 +287,8 @@ namespace Fig
                     continue;
                 }
 
+                diagnostics.EmitAll(manager);
+
                 CompiledModule *compiledModule = *compile_result;
 
                 auto exe_result = vm.Execute(compiledModule);

src/Sema/Analyzer.cpp

@@ -5,7 +5,6 @@
 
 #include <Ast/Ast.hpp>
 #include <Ast/Expr/MemberExpr.hpp>
-#include <Ast/Expr/ObjectInitExpr.hpp>
 #include <Ast/Stmt/ImplStmt.hpp>
 #include <Ast/Stmt/InterfaceDefStmt.hpp>
 #include <Ast/Stmt/StructDefStmt.hpp>
@@ -82,8 +81,11 @@ namespace Fig
             {
                 auto *s = static_cast<StructDefStmt *>(stmt);
                 if (globalTypes.contains(s->name))
+                {
                     return std::unexpected(
                         Error(ErrorType::RedeclarationError, "type redeclared", "", s->location));
+                }
+
                 auto *t = arena.Allocate<StructType>(s->name);
                 typeCtx.allTypes.push_back(t);
                 globalTypes[s->name] = t;
@@ -92,10 +94,14 @@ namespace Fig
             {
                 auto *f = static_cast<FnDefStmt *>(stmt);
                 if (f->name == "main")
+                {
                     hasMain = true;
+                }
                 if (globalSymbols.contains(f->name))
+                {
                     return std::unexpected(
                         Error(ErrorType::RedeclarationError, "func redeclared", "", f->location));
+                }
                 Symbol *sym =
                     arena.Allocate<Symbol>(f->name, Type{}, SymbolLocation::Global, 0, true);
                 globalSymbols[f->name]       = sym;
@@ -118,7 +124,9 @@ namespace Fig
                 {
                     auto res = resolveTypeExpr(f.type);
                     if (!res)
+                    {
                         return std::unexpected(res.error());
+                    }
                     st->AddField(f.name, *res, f.isPublic);
                 }
             }
@@ -185,10 +193,11 @@ namespace Fig
                 }
                 Type declT = v->typeSpecifier ? *resolveTypeExpr(v->typeSpecifier) : initT;
 
-                // 🔥 强类型校验：赋值拦截
+                // 赋值拦截
                 if (v->initExpr && !initT.isAssignableTo(declT))
                 {
-                    return std::unexpected(Error(ErrorType::TypeError,
+                    return std::unexpected(Error(
+                        ErrorType::TypeError,
                         "cannot assign '" + initT.toString() + "' to type '" + declT.toString()
                             + "'",
                         "",
@@ -210,7 +219,7 @@ namespace Fig
             case AstType::FnDefStmt: {
                 auto *f = static_cast<FnDefStmt *>(stmt);
 
-                // 3.10: 局部闭包延迟类型推导
+                // 局部闭包延迟类型推导
 
                 if (!f->resolvedSymbol) // 闭包？
                 {
@@ -243,7 +252,8 @@ namespace Fig
                 ScopeGuard   scopeGuard(env, true);
                 for (auto *p : f->params)
                 {
-                    env.current->locals[p->name] = arena.Allocate<Symbol>(p->name,
+                    env.current->locals[p->name] = arena.Allocate<Symbol>(
+                        p->name,
                         p->resolvedType,
                         SymbolLocation::Local,
                         env.current->nextLocalId++,
@@ -279,7 +289,8 @@ namespace Fig
                         return std::unexpected(c.error());
                     else if (!c->isAssignableTo(typeCtx.GetBasic(TypeTag::Bool)))
                     {
-                        return std::unexpected(Error(ErrorType::TypeError,
+                        return std::unexpected(Error(
+                            ErrorType::TypeError,
                             "condition must be Bool",
                             "",
                             elif->cond->location));
@@ -330,11 +341,15 @@ namespace Fig
                 break;
             }
             case AstType::BreakStmt:
-            case AstType::ContinueStmt:
+            case AstType::ContinueStmt: {
                 if (state.loopDepth <= 0)
+                {
                     return std::unexpected(
                         Error(ErrorType::SyntaxError, "outside loop", "", stmt->location));
+                }
                 break;
+            }
+
             case AstType::ReturnStmt: {
                 auto *rs   = static_cast<ReturnStmt *>(stmt);
                 Type  retT = typeCtx.GetBasic(TypeTag::Null);
@@ -345,10 +360,11 @@ namespace Fig
                         return std::unexpected(res.error());
                     retT = *res;
                 }
-                // 🔥 强类型校验：返回值拦截
+                // 返回值校验
                 if (state.currentFn && !retT.isAssignableTo(state.currentFn->resolvedReturnType))
                 {
-                    return std::unexpected(Error(ErrorType::TypeError,
+                    return std::unexpected(Error(
+                        ErrorType::TypeError,
                         "cannot return '" + retT.toString() + "' from function expecting '"
                             + state.currentFn->resolvedReturnType.toString() + "'",
                         "",
@@ -407,7 +423,8 @@ namespace Fig
                 auto *st = static_cast<StructType *>(targetType.base);
                 if (!st->fieldMap.contains(m->name))
                 {
-                    return std::unexpected(Error(ErrorType::TypeError,
+                    return std::unexpected(Error(
+                        ErrorType::TypeError,
                         "struct '" + st->name + "' has no field named '" + m->name + "'",
                         "",
                         m->location));
@@ -415,14 +432,18 @@ namespace Fig
                 // 字段类型
                 return expr->resolvedType = st->fields[st->fieldMap[m->name]].type;
             }
-            case AstType::ObjectInitExpr: {
-                auto *o   = static_cast<ObjectInitExpr *>(expr);
+            case AstType::NewExpr: {
+                auto *o   = static_cast<NewExpr *>(expr);
                 auto  res = resolveTypeExpr(o->typeExpr);
                 if (!res)
+                {
                     return std::unexpected(res.error());
+                }
                 if (!res->base || res->base->tag != TypeTag::Struct)
+                {
                     return std::unexpected(
                         Error(ErrorType::TypeError, "requires struct", "", o->location));
+                }
                 auto *st = static_cast<StructType *>(res->base);
                 for (auto &arg : o->args)
                 {
@@ -431,7 +452,9 @@ namespace Fig
                             Error(ErrorType::TypeError, "unknown field", "", arg.value->location));
                     auto r = analyzeExpr(arg.value);
                     if (!r)
+                    {
                         return std::unexpected(r.error());
+                    }
                     // 字段赋值类型检查
                     if (!arg.name.empty()
                         && !r->isAssignableTo(st->fields[st->fieldMap[arg.name]].type))
@@ -456,7 +479,8 @@ namespace Fig
                 if (in->op == BinaryOperator::Assign)
                 {
                     if (!r.isAssignableTo(l))
-                        return std::unexpected(Error(ErrorType::TypeError,
+                        return std::unexpected(Error(
+                            ErrorType::TypeError,
                             "cannot assign '" + r.toString() + "' to '" + l.toString() + "'",
                             "",
                             in->location));
@@ -511,19 +535,22 @@ namespace Fig
                         Error(ErrorType::TypeError, "callee is not a function", "", c->location));
 
                 auto *ft = static_cast<FuncType *>(calleeType.base);
+                
                 if (ft->paramTypes.size() != argTypes.size())
                 {
-                    return std::unexpected(Error(ErrorType::TypeError,
-                        "expected " + std::to_string(ft->paramTypes.size()) + " arguments, got "
-                            + std::to_string(argTypes.size()),
-                        "",
+                    return std::unexpected(Error(
+                        ErrorType::SyntaxError,
+                        std::format(
+                            "expected {} arguments, got {}", ft->paramTypes.size(), argTypes.size()),
+                        "none",
                         c->location));
                 }
                 for (size_t i = 0; i < argTypes.size(); ++i)
                 {
                     if (!argTypes[i].isAssignableTo(ft->paramTypes[i]))
                     {
-                        return std::unexpected(Error(ErrorType::TypeError,
+                        return std::unexpected(Error(
+                            ErrorType::TypeError,
                             "argument " + std::to_string(i + 1) + " expects '"
                                 + ft->paramTypes[i].toString() + "', got '" + argTypes[i].toString()
                                 + "'",
@@ -533,13 +560,86 @@ namespace Fig
                 }
                 return expr->resolvedType = ft->retType;
             }
+
+            case AstType::LambdaExpr: {
+                auto l = static_cast<LambdaExpr *>(expr);
+
+                Type returnType = typeCtx.GetBasic(TypeTag::Any);
+
+                if (l->returnType)
+                {
+                    auto tres = resolveTypeExpr(l->returnType);
+                    if (!tres)
+                    {
+                        return tres;
+                    }
+
+                    returnType = *tres;
+                }
+
+                FnDefStmt *f = arena.Allocate<FnDefStmt>(
+                    false, "LambdaFn", l->params, l->returnType, nullptr, l->location);
+
+                FnStateGuard fnGuard(state.currentFn, f);
+                ScopeGuard   scopeGuard(env, true);
+
+                DynArray<Type> paramTypes;
+                for (auto *p : l->params)
+                {
+                    auto pres = resolveTypeExpr(p->typeSpecifier);
+                    if (!pres)
+                    {
+                        return pres;
+                    }
+                    p->resolvedType = *pres;
+                    paramTypes.push_back(*pres);
+
+                    env.current->locals[p->name] = arena.Allocate<Symbol>(
+                        p->name,
+                        p->resolvedType,
+                        SymbolLocation::Local,
+                        env.current->nextLocalId++,
+                        false);
+                }
+
+                if (l->isExprBody)
+                {
+                    Expr *expr = static_cast<Expr *>(l->body);
+                    if (auto r = analyzeExpr(expr); !r)
+                    {
+                        return r;
+                    }
+                    if (!expr->resolvedType.isAssignableTo(state.currentFn->resolvedReturnType))
+                    {
+                        return std::unexpected(Error(
+                            ErrorType::TypeError,
+                            "cannot return '" + state.currentFn->resolvedReturnType.toString()
+                                + "' from lambda function expecting '"
+                                + state.currentFn->resolvedReturnType.toString() + "'",
+                            "",
+                            expr->location));
+                    }
+                }
+                else
+                {
+                    Stmt *stmt = static_cast<Stmt *>(l->body);
+                    if (auto r = analyzeStmt(stmt); !r)
+                    {
+                        return std::unexpected(r.error());
+                    }
+                }
+
+                return l->resolvedType = typeCtx.CreateFuncType(paramTypes, returnType);
+            }
+
             default: break;
         }
+
         return expr->resolvedType = typeCtx.GetBasic(TypeTag::Any);
     }
 
-    Result<Symbol *, Error> Analyzer::resolveSymbolInternal(
-        const String &name, const SourceLocation &loc, Scope *s)
+    Result<Symbol *, Error>
+    Analyzer::resolveSymbolInternal(const String &name, const SourceLocation &loc, Scope *s)
     {
         Scope *curr = s;
         while (curr)
@@ -607,13 +707,46 @@ namespace Fig
             return std::unexpected(
                 Error(ErrorType::UseUndeclaredIdentifier, "unknown type", "", texpr->location));
         }
-        if (texpr->type == AstType::NullableTypeExpr)
+        else if (texpr->type == AstType::NullableTypeExpr)
         {
             auto res = resolveTypeExpr(static_cast<NullableTypeExpr *>(texpr)->inner);
-            if (res)
-                res->isNullable = true;
+            if (!res)
+            {
+                return res;
+            }
+
+            res->isNullable = true;
             return res;
         }
+        else if (texpr->type == AstType::FnTypeExpr)
+        {
+            auto f = static_cast<FnTypeExpr *>(texpr);
+
+            DynArray<Type> paraTypes;
+            Type           returnType = typeCtx.GetBasic(TypeTag::Any);
+
+            for (auto &pt : f->paraTypes)
+            {
+                auto result = resolveTypeExpr(pt);
+                if (!result)
+                {
+                    return result;
+                }
+                paraTypes.push_back(*result);
+            }
+
+            if (f->returnType)
+            {
+                auto result = resolveTypeExpr(f->returnType);
+                if (!result)
+                {
+                    return result;
+                }
+                returnType = *result;
+            }
+            return typeCtx.CreateFuncType(paraTypes, returnType);
+        }
+
         return typeCtx.GetBasic(TypeTag::Any);
     }
 } // namespace Fig

src/Sema/AnalyzerTest.cpp

@@ -20,7 +20,12 @@ void runTest(const std::string &path)
     }
 
     Lexer  lexer(source, String(path));
-    Parser parser(lexer, srcManager, String(path));
+
+    Diagnostics diagnostics;
+
+    Parser parser(lexer, srcManager, String(path), diagnostics);
+
+    diagnostics.EmitAll(srcManager);
 
     auto pRes = parser.Parse();
     if (!pRes)

src/Sema/Type.cpp

@@ -39,10 +39,15 @@ namespace Fig
     bool Type::isAssignableTo(const Type &target) const
     {
         if (target.is(TypeTag::Any) || this->is(TypeTag::Any))
-            return true; // Any 逃逸通道
+        {
+            return true; // Any 逃逸
+        }
         if (this->is(TypeTag::Null) && target.isNullable)
+        {
             return true; // Null 安全赋值
-        return this->base == target.base && (!this->isNullable || target.isNullable);
+        }
+        
+        return *this->base == *target.base && (!this->isNullable || target.isNullable);
     }
 
     TypeContext::TypeContext()
@@ -65,7 +70,9 @@ namespace Fig
     TypeContext::~TypeContext()
     {
         for (auto t : allTypes)
+        {
             delete t;
+        }
     }
 
     Type TypeContext::GetBasic(TypeTag tag, bool nullable)

src/Sema/Type.hpp

@@ -51,6 +51,11 @@ namespace Fig
         String  name;
         BaseType(TypeTag t, String n) : tag(t), name(std::move(n)) {}
         virtual ~BaseType() = default;
+
+        bool operator==(const BaseType &other) const
+        {
+            return tag == other.tag && name == other.name;
+        }
     };
 
     class FuncType : public BaseType
@@ -62,6 +67,11 @@ namespace Fig
             BaseType(TypeTag::Function, "Function"), paramTypes(std::move(params)), retType(ret)
         {
         }
+
+        bool operator==(const FuncType &other) const
+        {
+            return paramTypes == other.paramTypes && retType == other.retType;    
+        }
     };
 
     class StructType : public BaseType
@@ -85,6 +95,11 @@ namespace Fig
             fields.push_back({name, type, isPublic, (int) idx});
             fieldMap[name] = idx;
         }
+
+        bool operator==(const StructType &other) const
+        {
+            return this == &other; // 即使是两个完全一样的struct, 也认作不同的type
+        }
     };
 
     class InterfaceType : public BaseType
@@ -98,6 +113,11 @@ namespace Fig
         };
         HashMap<String, MethodSig> methods;
         InterfaceType(String n) : BaseType(TypeTag::Interface, std::move(n)) {}
+
+        bool operator==(const InterfaceType &other) const
+        {
+            return this == &other; // 即使是两个完全一样的interface, 也认作不同的type
+        }
     };
 
     class TypeContext

src/VM/Entry.cpp

@@ -5,26 +5,62 @@
     @date 2026-03-13
 */
 
-
 #include <VM/Entry.hpp>
 
+#include <chrono>
 #include <filesystem>
 
 #include <Core/Core.hpp>
 #include <SourceManager/SourceManager.hpp>
 
+#include <Bytecode/Disassembler.hpp>
+#include <Compiler/Compiler.hpp>
 #include <Lexer/Lexer.hpp>
 #include <Parser/Parser.hpp>
+#include <Repl/Repl.hpp>
 #include <Sema/Analyzer.hpp>
-#include <Compiler/Compiler.hpp>
 #include <VM/VM.hpp>
 
 namespace Fig::Entry
 {
-    void RunFromPath(const String &path)
+    void RunFromPath(const String &path, const Config &conf)
     {
         namespace fs = std::filesystem;
 
+        using clock = std::chrono::steady_clock;
+
+        auto format_print_time = [](std::chrono::nanoseconds nsecs) {
+            auto &out   = CoreIO::GetStdOut();
+            auto  count = nsecs.count();
+
+            auto old_flags     = out.flags();
+            auto old_precision = out.precision();
+
+            if (count < 1'000)
+            {
+                // < 1μs 纳秒
+                out << count << "ns";
+            }
+            else if (count < 1'000'000)
+            {
+                // 1μs ~ 1ms 微秒 保留 2 位小数
+                out << std::fixed << std::setprecision(2) << (count / 1'000.0) << "μs";
+            }
+            else if (count < 1'000'000'000)
+            {
+                // 1ms ~ 1s 毫秒 保留 2 位小数
+                out << std::fixed << std::setprecision(2) << (count / 1'000'000.0) << "ms";
+            }
+            else
+            {
+                // >= 1s 秒 保留 3 位小数
+                out << std::fixed << std::setprecision(3) << (count / 1'000'000'000.0) << "s";
+            }
+
+            out.flags(old_flags);
+            out.precision(old_precision);
+        };
+
         fs::path _fspath(path.toStdString());
 
         if (!fs::exists(_fspath))
@@ -53,18 +89,28 @@ namespace Fig::Entry
         const String &source = manager.GetSource();
 
         Lexer lexer(source, fileName);
-        Parser parser(lexer, manager, fileName);
 
+        Diagnostics diagnostics;
+
+        Parser parser(lexer, manager, fileName, diagnostics);
+
+        auto parse_start  = clock::now();
         auto parse_result = parser.Parse();
+        auto parse_end    = clock::now();
+
         if (!parse_result)
         {
             ReportError(parse_result.error(), manager);
             std::exit(1);
         }
+
         Program *program = *parse_result;
 
         Analyzer analyer(manager);
+
+        auto analyze_start  = clock::now();
         auto analyze_result = analyer.Analyze(program);
+        auto analyze_end    = clock::now();
 
         if (!analyze_result)
         {
@@ -72,10 +118,12 @@ namespace Fig::Entry
             std::exit(1);
         }
 
-        Diagnostics diagnostics;
         Compiler compiler(manager, diagnostics);
 
+        auto compile_start  = clock::now();
         auto compile_result = compiler.Compile(program);
+        auto compile_end    = clock::now();
+
         diagnostics.EmitAll(manager);
 
         if (!compile_result)
@@ -86,15 +134,66 @@ namespace Fig::Entry
 
         CompiledModule *compiledModule = *compile_result;
 
+        if (conf.dump)
+        {
+            Disassembler disassembler;
+            disassembler.DisassembleModule(compiledModule);
+        }
+
         VM vm;
 
+        auto execute_start  = clock::now();
         auto execute_result = vm.Execute(compiledModule);
+        auto execute_end    = clock::now();
+
         if (!execute_result)
         {
             ReportError(execute_result.error(), manager);
             std::exit(1);
         }
 
+        if (conf.pregs)
+        {
+            vm.PrintRegisters();
+        }
+
+        if (conf.time)
+        {
+            auto parse_time = parse_end - parse_start;
+            CoreIO::GetStdOut() << "Parse: ";
+            format_print_time(parse_time);
+            CoreIO::GetStdOut() << " | ";
+
+            auto analyze_time = analyze_end - analyze_start;
+            CoreIO::GetStdOut() << "Analyze: ";
+            format_print_time(analyze_time);
+            CoreIO::GetStdOut() << " | ";
+
+            auto compile_time = compile_end - compile_start;
+            CoreIO::GetStdOut() << "Compile: ";
+            format_print_time(compile_time);
+            CoreIO::GetStdOut() << " | ";
+
+            auto execute_time = execute_end - execute_start;
+            CoreIO::GetStdOut() << "Execute: ";
+            format_print_time(execute_time);
+            CoreIO::GetStdOut() << " | ";
+
+            auto total = parse_time + analyze_time + compile_time + execute_time;
+            CoreIO::GetStdOut() << "Total: ";
+            format_print_time(total);
+            CoreIO::GetStdOut() << '\n';
+        }
+
         delete compiledModule;
     }
+
+    std::uint32_t RunRepl()
+    {
+        Repl          repl(CoreIO::GetStdCin(), CoreIO::GetStdOut(), CoreIO::GetStdErr());
+        std::uint32_t result = repl.Start();
+
+        CoreIO::GetStdOut() << "Repl exited with code " << result << '\n';
+        return result;
+    }
 }; // namespace Fig::Entry

src/VM/Entry.hpp

@@ -9,5 +9,18 @@
 
 namespace Fig::Entry
 {
-    void RunFromPath(const String &);
+    struct Config
+    {
+        enum Mode
+        {
+            Debug,
+            Normal
+        } mode;
+        bool dump;
+        bool pregs;
+        bool time;
+    };
+
+    void RunFromPath(const String &, const Config &conf);
+    std::uint32_t RunRepl();
 };

src/VM/VM.cpp

@@ -209,8 +209,9 @@ namespace Fig
                 "none",
                 *currentFrame->proto->locations[ipIdx]));
         }
-        else
+        else [[likely]]
         {
+
             Object *obj = callee.AsObject();
             if (!obj->isFunction())
             {

src/VM/VM.hpp

@@ -329,7 +329,7 @@ namespace Fig
                     Op::iAsBx(OpCode::Exit_MaxRecursionDepthExceeded, 0, 0);
                 return &POISON_MAX_RECURSION_DEPTH_EXCEED_INST;
             }
-
+            [[likely]]
             *currentFrame = CallFrame{nullptr, proto, proto->code.data(), base};
             return currentFrame->ip;
         }
@@ -343,7 +343,7 @@ namespace Fig
                     Op::iAsBx(OpCode::Exit_MaxRecursionDepthExceeded, 0, 0);
                 return &POISON_MAX_RECURSION_DEPTH_EXCEED_INST;
             }
-
+            [[likely]]
             *currentFrame = CallFrame{closure, closure->proto, closure->proto->code.data(), base};
             return currentFrame->ip;
         }

src/main.cpp

@@ -19,9 +19,13 @@ int main(int argc, char **argv)
 
     ArgParser::ArgumentParser argparser("Fig", "Fig Toolchain");
 
+    argparser.AddFlag('r', "repl");
     argparser.AddFlag('h', "help").Help("Print the help message");
     argparser.AddFlag('v', "version").Help("Show toolchain version");
     argparser.AddFlag("license").Help("Print the license text");
+    argparser.AddFlag("dump").Help("Dump the bytecode");
+    argparser.AddFlag("pregs").Help("Print vm non-null registers");
+    argparser.AddFlag("time").Help("Print the execution time");
 
     auto res = argparser.Parse(argc, argv);
     if (!res)
@@ -32,9 +36,13 @@ int main(int argc, char **argv)
 
     auto &args = *res;
 
+    bool runRepl     = args.HasFlag("repl");
     bool showHelp    = args.HasFlag("help");
     bool showVersion = args.HasFlag("version");
     bool showLicense = args.HasFlag("license");
+    bool dump        = args.HasFlag("dump");
+    bool pregs       = args.HasFlag("pregs");
+    bool time        = args.HasFlag("time");
 
     if (showHelp)
     {
@@ -44,10 +52,12 @@ int main(int argc, char **argv)
 
     if (showVersion)
     {
-        out << std::format("Fig {}, copyright (c) 2025-2026 PuqiAR, under the {} License\n",
+        out << std::format(
+            "Fig {}, copyright (c) 2025-2026 PuqiAR, under the {} License\n",
             Core::VERSION,
             Core::LICENSE);
-        out << std::format("Build time: {} [{} x{} on {}]\n",
+        out << std::format(
+            "Build time: {} [{} x{} on {}]\n",
             Core::COMPILE_TIME,
             Core::COMPILER,
             Core::ARCH,
@@ -66,6 +76,11 @@ int main(int argc, char **argv)
         return 0;
     }
 
+    if (runRepl)
+    {
+        return Entry::RunRepl();
+    }
+
     if (posSize > 1)
     {
         err << "Error: Too more positionals, expect 1. Use Fig [Fig source code file (.fig)]\n";
@@ -77,8 +92,10 @@ int main(int argc, char **argv)
         return 1;
     }
 
+    Entry::Config config{.mode = Entry::Config::Normal, .dump = dump, .pregs = pregs, .time = time};
+
     const String &path = positionals.front();
-    Entry::RunFromPath(path);
+    Entry::RunFromPath(path, config);
 
     return 0;
 }

xmake.lua

@@ -15,6 +15,10 @@ elseif is_plat("windows") then
     add_ldflags("-Wl,--stack,268435456")
 end
 
+if is_mode("release") then
+    set_optimize("fastest")
+end
+
 set_languages("c++23")
 add_includedirs("src")