修复右结合绑定力错误

src/Ast/Operator.cpp

@@ -51,7 +51,7 @@ namespace Fig
             {TokenType::PercentEqual, BinaryOperator::ModuloAssign},
             {TokenType::CaretEqual, BinaryOperator::BitXorAssign},
 
-            {TokenType::Pipe, BinaryOperator::BitAnd},
+            {TokenType::Pipe, BinaryOperator::BitOr},
             {TokenType::Ampersand, BinaryOperator::BitAnd},
             {TokenType::ShiftLeft, BinaryOperator::ShiftLeft},
             {TokenType::ShiftRight, BinaryOperator::ShiftRight},
@@ -136,23 +136,22 @@ namespace Fig
     }
 
     BindingPower GetBinaryOpRBp(BinaryOperator op)
+    {
+        switch (op)
         {
             /*
                 右结合，左绑定力 >= 右
                 a = b = c
                 a = (b = c)
-            a.b.c
             */
-        switch (op)
-        {
-            case BinaryOperator::Assign: return GetBinaryOpLBp(op);
-            case BinaryOperator::AddAssign: return GetBinaryOpLBp(op);
-            case BinaryOperator::SubAssign: return GetBinaryOpLBp(op);
-            case BinaryOperator::MultiplyAssign: return GetBinaryOpLBp(op);
-            case BinaryOperator::DivideAssign: return GetBinaryOpLBp(op);
-            case BinaryOperator::ModuloAssign: return GetBinaryOpLBp(op);
-            case BinaryOperator::BitXorAssign: return GetBinaryOpLBp(op);
-            case BinaryOperator::Power: return GetBinaryOpLBp(op);
+            case BinaryOperator::Assign:
+            case BinaryOperator::AddAssign:
+            case BinaryOperator::SubAssign:
+            case BinaryOperator::MultiplyAssign:
+            case BinaryOperator::DivideAssign:
+            case BinaryOperator::ModuloAssign:
+            case BinaryOperator::BitXorAssign:
+            case BinaryOperator::Power: return GetBinaryOpLBp(op) - 1;
 
             default:
                 /*

src/Parser/ExprParser.cpp

@@ -122,12 +122,12 @@ namespace Fig
 
         while (true)
         {
-            token = currentToken();
             if (shouldTerminate())
             {
                 return lhs;
             }
 
+            token = currentToken();
             if (IsTokenOp(token.type /* isBinary = true */)) // 是否为二元运算符
             {
                 BinaryOperator op  = TokenToBinaryOp(token);
@@ -136,7 +136,7 @@ namespace Fig
                 {
                     // 前操作数的右绑定力比当前操作数的左绑定力大
                     // lhs被吸走
-                    return lhs;
+                    break;
                 }
 
                 const auto &result = parseInfixExpr(lhs);
@@ -154,6 +154,7 @@ namespace Fig
                 return lhs;
             }
         }
+        return lhs;
     }
 
 }; // namespace Fig

src/Parser/Parser.hpp

@@ -34,7 +34,7 @@ namespace Fig
 
         bool isEOF = false;
 
-        const Token &nextToken()
+        Token nextToken()
         {
             assert(!isEOF && "nextToken: eof but called nextToken");
             if (index + 1 < buffer.size())
@@ -57,12 +57,16 @@ namespace Fig
             return token;
         }
 
-        inline const Token &prevToken()
+        inline Token prevToken()
         {
+            if (buffer.size() < 2)
+            {
+                return currentToken();
+            }
             return buffer[buffer.size() - 2];
         }
 
-        inline const Token &currentToken()
+        inline Token currentToken()
         {
             if (buffer.empty())
             {
@@ -71,7 +75,7 @@ namespace Fig
             return buffer.back();
         }
         
-        const Token &peekToken(size_t lookahead = 1)
+        Token peekToken(size_t lookahead = 1)
         {
             assert(!isEOF && "peekToken: eof but called peekToken");