Found a big problem with order of operations.

I believe this is because I'm using right tail recursion, but I'm not really
sure how I could change it for this program.

order of operations is being observed perfectly, but then operations are being
performed from right to left, not left to right.  I think I may be reducing
too frequently, honestly.

4 files changed, 46 insertions, 18 deletions

diff --git a/src/parser.cpp b/src/parser.cpp
index c7cf994..701c4bd 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -20,8 +20,7 @@ Parser::~Parser()
 Expression *Parser::parse()

 {

     pCurExp = new Expression();

-    exprR();

-    reduce();

+    statement();

 

     printState("Final");

 

@@ -40,7 +39,7 @@ void Parser::exprR()
 

 void Parser::expr()

 {

-    //Bu::sio << "::expr " << lex[0] << Bu::sio.nl;

+    Bu::sio << "::expr " << lex[0] << Bu::sio.nl;

     if( lex[0].eType == Token::tEndOfInput )

         return;

 

@@ -57,7 +56,7 @@ void Parser::expr()
         case Token::tModulus:

             Token t = lex[0];

             lex.nextToken();

-            //Bu::sio << "->expr " << t << " " << lex[0] << Bu::sio.nl;

+            Bu::sio << "->expr " << t << " " << lex[0] << Bu::sio.nl;

             if( lex[0].eType == Token::tOpenParen )

             {

                 exprP();

@@ -70,10 +69,10 @@ void Parser::expr()
                 if( lex[0].eType == Token::tNumber ||

                     lex[0].eType == Token::tVariable )

                 {

-                    //Bu::sio << "->expr " << t <<

-                    //    " " << lex[0] <<

-                    //    " " << lex[1] <<

-                    //    Bu::sio.nl;

+                    Bu::sio << "->expr " << t <<

+                        " " << lex[0] <<

+                        " " << lex[1] <<

+                        Bu::sio.nl;

                     shift( lex[0] );

                     if( lex[1].eType&Token::mMetaOperator )

                     {

@@ -111,14 +110,14 @@ void Parser::expr()
                 else if( lex[0].eType == Token::tMinus )

                 {

                     // This is negation

-                    //Bu::sio << "next token: " << lex[0] << Bu::sio.nl;

+                    Bu::sio << "next token: " << lex[0] << Bu::sio.nl;

                     printState("inline-negate");

                     exprP();

                     printState("inline-negate-post");

                     shift( t );

                     printState("inline-negate-post2");

 

-                    //Bu::sio << "??? " << lex[0] << Bu::sio.nl;

+                    Bu::sio << "??? " << lex[0] << Bu::sio.nl;

                 }

             }

             break;

@@ -157,7 +156,7 @@ void Parser::exprP()
             exprR();

             if( lex[0].eType != Token::tCloseParen )

             {

-                //Bu::sio << "::exprP " << lex[0] << Bu::sio.nl;

+                Bu::sio << "::exprP " << lex[0] << Bu::sio.nl;

                 throw Bu::ExceptionBase("Expected close paren");

             }

             shift( lex[0] );

@@ -175,6 +174,21 @@ void Parser::exprP()
             break;

     }

 }

+

+void Parser::statement()

+{

+    if( lex[0].eType == Token::tCommand )

+    {

+        lex.setMode( Lexer::modeCommand );

+        lex.setMode( Lexer::modeNormal );

+    }

+    else

+    {

+        exprR();

+        reduce();

+    }

+}

+

 /*

 case Token::tCommand:

     lex.setMode( Lexer::modeCommand );

@@ -403,7 +417,6 @@ int Parser::getPriority( Token::Type eType )
 

 void Parser::printState( const Bu::String &sTag )

 {

-    /*

     Bu::sio << "----------------" << Bu::sio.nl;

     Bu::sio << sTag << " stack:";

     for( TokenStack::iterator i = tsParse.begin(); i; i++ )

@@ -418,6 +431,5 @@ void Parser::printState( const Bu::String &sTag )
     }

     Bu::sio << Bu::sio.nl;

     Bu::sio << "----------------" << Bu::sio.nl;

-    */

 }

 

diff --git a/src/parser.h b/src/parser.h
index 1e0d1c4..60dd8e1 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -55,6 +55,7 @@ private:
     void expr();

     void exprP();

     void exprR();

+    void statement();

 

 private:

     void shift( const Token &t );

diff --git a/src/scriptengine.cpp b/src/scriptengine.cpp
index 7b5df03..b828409 100644
--- a/src/scriptengine.cpp
+++ b/src/scriptengine.cpp
@@ -56,19 +56,35 @@ Number ScriptEngine::exec( Expression *pExpr )
                 break;
 
             case Token::tPlus:
-                sNums.push( sNums.peekPop() + sNums.peekPop() );
+                {
+                    Number a = sNums.peekPop();
+                    Number b = sNums.peekPop();
+                    sNums.push( a + b );
+                }
                 break;
 
             case Token::tMinus:
-                sNums.push( sNums.peekPop() - sNums.peekPop() );
+                {
+                    Number a = sNums.peekPop();
+                    Number b = sNums.peekPop();
+                    sNums.push( a - b );
+                }
                 break;
 
             case Token::tDivide:
-                sNums.push( sNums.peekPop() / sNums.peekPop() );
+                {
+                    Number a = sNums.peekPop();
+                    Number b = sNums.peekPop();
+                    sNums.push( a / b );
+                }
                 break;
 
             case Token::tMultiply:
-                sNums.push( sNums.peekPop() * sNums.peekPop() );
+                {
+                    Number a = sNums.peekPop();
+                    Number b = sNums.peekPop();
+                    sNums.push( a * b );
+                }
                 break;
 
             case Token::tNegate:
diff --git a/src/token.h b/src/token.h
index 4ad1136..5bede41 100644
--- a/src/token.h
+++ b/src/token.h
@@ -40,7 +40,6 @@ public:
         mMetaOperator   = 0x4000,

         mMetaAltOp      = 0x8000,

         mMetaMeta       = 0x0100,

-

     };

 

     Token();