[Feat] 函数支持可变参数!! func (x...) 获取到的x类型为List

[Impl] Lexer现在贪心检测符号,拓展时可以直接添加到symbol_map

src/Ast/functionParameters.hpp

@@ -21,6 +21,9 @@ namespace Fig::Ast
         PosParasType posParas;
         DefParasType defParas; // default parameters
 
+        FString variadicPara;
+        bool variadic = false;
+
         FunctionParameters()
         {
             
@@ -30,6 +33,11 @@ namespace Fig::Ast
             posParas = std::move(_posParas);
             defParas = std::move(_defParas);
         }
+        FunctionParameters(FString _variadicPara)
+        {
+            variadicPara = std::move(_variadicPara);
+            variadic = true;
+        }
 
         size_t size() const
         {

src/Evaluator/evaluator.cpp

@@ -31,10 +31,10 @@ namespace Fig
             if (mod.ctx->contains(member) && mod.ctx->isVariablePublic(member))
             {
                 return LvObject(
-                    mod.ctx->get(member) 
+                    mod.ctx->get(member));
-                );
             }
-            else {
+            else
+            {
                 throw EvaluatorError(
                     u8"VariableNotFoundError",
                     std::format(
@@ -146,8 +146,7 @@ namespace Fig
             return LvObject(
                 base.get(),
                 indexVal,
-                LvObject::Kind::StringElement
+                LvObject::Kind::StringElement);
-            );
         }
         else
         {
@@ -366,6 +365,17 @@ namespace Fig
 
         // check argument, all types of parameters
         Ast::FunctionParameters fnParas = fnStruct.paras;
+
+        // create new context for function call
+        auto newContext = std::make_shared<Context>(FString(std::format("<Function {}()>", fnName.toBasicString())),
+                                                    fnStruct.closureContext);
+
+        if (fnParas.variadic)
+            goto VariadicFilling;
+        else
+            goto NormalFilling;
+
+    NormalFilling: {
         if (fnArgs.getLength() < fnParas.posParas.size() || fnArgs.getLength() > fnParas.size())
         {
             throw RuntimeError(FString(
@@ -437,9 +447,7 @@ namespace Fig
             ObjectPtr defaultVal = eval(fnParas.defParas[defParamIndex].second.second, ctx);
             evaluatedArgs.argv.push_back(defaultVal);
         }
-        // create new context for function call
+
-        auto newContext = std::make_shared<Context>(FString(std::format("<Function {}()>", fnName.toBasicString())),
-                                                    fnStruct.closureContext);
         // define parameters in new context
         for (size_t j = 0; j < fnParas.size(); j++)
         {
@@ -459,6 +467,25 @@ namespace Fig
             AccessModifier argAm = AccessModifier::Const;
             newContext->def(paramName, paramType, argAm, evaluatedArgs.argv[j]);
         }
+        goto ExecuteBody;
+    }
+
+    VariadicFilling: {
+        List list;
+        for (auto &exp : fnArgs.argv)
+        {
+            list.push_back(eval(exp, ctx)); // eval arguments in current scope
+        }
+        newContext->def(
+            fnParas.variadicPara,
+            ValueType::List,
+            AccessModifier::Const,
+            std::make_shared<Object>(
+                list));
+        goto ExecuteBody;
+    }
+
+    ExecuteBody: {
         // execute function body
         ObjectPtr retVal = Object::getNullInstance();
         for (const auto &stmt : fnStruct.body->stmts)
@@ -482,6 +509,7 @@ namespace Fig
         }
         return retVal;
     }
+    }
 
     RvObject Evaluator::eval(Ast::Expression exp, ContextPtr ctx)
     {

src/Lexer/lexer.cpp

@@ -10,6 +10,8 @@ namespace Fig
 {
 
     const std::unordered_map<FString, TokenType> Lexer::symbol_map{
+        // 三字符
+        {FString(u8"..."), TokenType::TripleDot},
         // 双字符
         {FString(u8"=="), TokenType::Equal},
         {FString(u8"!="), TokenType::NotEqual},
@@ -380,30 +382,59 @@ namespace Fig
     {
         FString sym;
         UTF8Char ch = *it;
-
         sym += ch.getString();
-        UTF8Char peek = UTF8Char(u8"");
+
-        if (hasNext() and (peek = it.peek()).isPunct()) // 窥探下一个操作符
+        auto startsWith = [&](const FString &prefix) -> bool {
-        {
+            for (const auto &p : symbol_map)
-            FString symd = FString(sym + peek.getString());
-            if (this->symbol_map.contains(symd))
             {
-                // Operator length is 2
+                const FString &op = p.first;
-                next();
+                if (op.starts_with(prefix))
-                sym = symd;
+                    return true;
             }
-            // Operator length is 1
+            return false;
-            else if (!this->symbol_map.contains(sym))
+        };
+
+        if (!startsWith(sym))
+        {
+            error = SyntaxError(
+                FString(std::format("No such operator: {}", sym.toBasicString())),
+                this->line, it.column());
+            next();
+            return IllegalTok;
+        }
+
+        while (hasNext())
+        {
+            UTF8Char peek = it.peek();
+            if (!peek.isPunct())
+                break;
+
+            FString candidate = sym + FString(peek.getString());
+
+            if (startsWith(candidate))
             {
-                // check legality
+                next();
-                error = SyntaxError(FString(
+                sym = candidate;
-                                        std::format("No such a operator: {}", sym.toBasicString())),
+            }
-                                    this->line, it.column());
+            else
+            {
+                break;
             }
         }
+
+        if (!symbol_map.contains(sym))
+        {
+            error = SyntaxError(
+                FString(std::format("No such operator: {}", sym.toBasicString())),
+                this->line, it.column());
+            next();
+            return IllegalTok;
+        }
+
         next();
-        return Token(sym, this->symbol_map.at(sym)); // const object 'symbol_map', operator[] call is invalid
+        return Token(sym, symbol_map.at(sym));
     }
+
     Token Lexer::scanComments()
     {
         // entry: when iterator current char is '/' and peek is '/' or '*'

src/Parser/parser.cpp

@@ -144,6 +144,7 @@ namespace Fig
 
         Ast::FunctionParameters::PosParasType pp;
         Ast::FunctionParameters::DefParasType dp;
+        FString variaPara;
         while (true)
         {
             if (isThis(TokenType::RightParen))
@@ -153,7 +154,7 @@ namespace Fig
             }
             expect(TokenType::Identifier, FString(u8"Identifier or `)`")); // check current
             FString pname = currentToken().getValue();
-            next();                        // skip pname
+            next();                                    // skip pname
             if (isThis(TokenType::Assign)) // =
             {
                 next();
@@ -187,6 +188,19 @@ namespace Fig
                     }
                 }
             }
+            else if (isThis(TokenType::TripleDot))
+            {
+                variaPara = pname;
+                next(); // skip `...`
+                if (!isThis(TokenType::RightParen))
+                    throw SyntaxError(
+                        u8"Expects right paren, variable parameter function can only have one parameter",
+                        currentAAI.line,
+                        currentAAI.column
+                    );
+                next(); // skip `)`
+                return Ast::FunctionParameters(variaPara);
+            }
             else
             {
                 pp.push_back({pname, ValueType::Any.name});

src/Token/token.hpp

@@ -105,6 +105,8 @@ namespace Fig
         DoublePipe,      // ||
         Walrus,          // :=
         Power,           // **
+
+        TripleDot,       // ... for variadic parameter
     };
 
     class Token final