Variables work.

1 files changed, 107 insertions, 7 deletions

diff --git a/src/parser.cpp b/src/parser.cpp
index 21ccc11..5bb0aa6 100644
--- a/src/parser.cpp
+++ b/src/parser.cpp
@@ -28,7 +28,7 @@ void Parser::parse()
                 unwind();

                 if( !tsTerminal.isEmpty() )

                 {

-                    Bu::println( rOut, "%1").arg( *tsTerminal.peek().nVal );

+                    Bu::println( rOut, "%1").arg( deref( tsTerminal.peek() ) );

                 }

                 tsTerminal.clear();

                 break;

@@ -58,6 +58,9 @@ void Parser::parse()
                         {

                             Bu::println( rOut, "Scale changed to: %1").

                                 arg( lex.getScale() );

+                            for( VarHash::iterator i = hVars.begin(); i; i++ )

+                                (*i).setScale( lex.getScale() );

+                            nZero = Number( lex.getScale(), lex.getRadix() );

                         }

                     }

                     else

@@ -85,6 +88,8 @@ void Parser::parse()
                             lex.setRadix( i );

                             Bu::println( rOut, "Radix changed to: %1").

                                 arg( lex.getRadix() );

+                            hVars.clear();

+                            nZero = Number( lex.getScale(), lex.getRadix() );

                         }

                     }

                     else

@@ -93,6 +98,47 @@ void Parser::parse()
                                 "the parameter to radix.");

                     }

                 }

+                else if( *t.sVal == "vars" )

+                {

+                    Bu::println( rOut, "Declared variables:");

+                    for( VarHash::iterator i = hVars.begin(); i; i++ )

+                    {

+                        Bu::println( rOut, " - %1 = %2").

+                            arg( i.getKey() ).arg( *i );

+                    }

+                    Bu::println( rOut, "");

+                }

+                else if( *t.sVal == "help" || *t.sVal == "h" || *t.sVal == "?" )

+                {

+                    Bu::println( rOut,

+                        "All commands start with a '\\'.  The following commands are defined:\n"

+                        " \\help, \\h, \\?   - This help\n"

+                        " \\exit, \\quit    - Exit the program\n"

+                        " \\radix          - Display the current radix (base)\n"

+                        " \\radix <num>    - Set the radix to anything between 2 and 36 (inclusive)\n"

+                        " \\scale          - Display the current scale\n"

+                        " \\scale <num>    - Set the current scale\n"

+                        " \\vars           - List all defined variables\n"

+                        "\n"

+                        "All variables must prefixed with a $ but otherwise can be used anywhere a\n"

+                        "number can be used.  To assign a variable use =, i.e.:\n"

+                        "  $amnt = $rate * 144000.09\n"

+                        "\n"

+                        "When using a radix greater than 10 all extended digits are lowercase letters\n"

+                        "starting with 'a'.  Upper case is not currently supported.\n"

+                        "\n"

+                        "All numbers are interpreted in the current radix, this means that you need to\n"

+                        "set the radix using the current radix, even though the current value is aways\n"

+                        "displayed in decimal.  That is, to go to base 8 and back to base 10 you would:\n"

+                        "  \\radix 8\n"

+                        "  Radix changed to: 8\n"

+                        "  \\radix 12\n"

+                        "  Radix changed to: 10\n"

+                        "\n"

+                        "Changing the radix always clears all variables.\n"

+                        );

+

+                }

                 else

                 {

                     Bu::println( rOut, "ERROR: Unknown command '%1'").

@@ -101,6 +147,7 @@ void Parser::parse()
                 break;

 

             case Token::tNumber:

+            case Token::tVariable:

                 tsTerminal.push( t );

                 break;

 

@@ -150,7 +197,9 @@ void Parser::unwind()
                     Token b = tsTerminal.peekPop();

                     Token a = tsTerminal.peekPop();

                     tsTerminal.push(

-                        Token( Token::tNumber, new Number( *a.nVal + *b.nVal ) )

+                        Token( Token::tNumber,

+                            new Number( deref(a) + deref(b) )

+                            )

                         );

                 }

                 break;

@@ -160,7 +209,9 @@ void Parser::unwind()
                     Token b = tsTerminal.peekPop();

                     Token a = tsTerminal.peekPop();

                     tsTerminal.push(

-                        Token( Token::tNumber, new Number( *a.nVal - *b.nVal ) )

+                        Token( Token::tNumber,

+                            new Number( deref(a) - deref(b) )

+                            )

                         );

                 }

                 break;

@@ -170,7 +221,9 @@ void Parser::unwind()
                     Token b = tsTerminal.peekPop();

                     Token a = tsTerminal.peekPop();

                     tsTerminal.push(

-                        Token( Token::tNumber, new Number( *a.nVal * *b.nVal ) )

+                        Token( Token::tNumber,

+                            new Number( deref(a) * deref(b) )

+                            )

                         );

                 }

                 break;

@@ -180,7 +233,9 @@ void Parser::unwind()
                     Token b = tsTerminal.peekPop();

                     Token a = tsTerminal.peekPop();

                     tsTerminal.push(

-                        Token( Token::tNumber, new Number( *a.nVal / *b.nVal ) )

+                        Token( Token::tNumber,

+                            new Number( deref(a) / deref(b) )

+                            )

                         );

                 }

                 break;

@@ -202,8 +257,28 @@ void Parser::unwind()
                 }

                 break;

 

+            case Token::tEquals:

+                {

+                    Token b = tsTerminal.peekPop();

+                    Token a = tsTerminal.peekPop();

+                    if( a.eType != Token::tVariable )

+                    {

+                        Bu::println("The left hand side of a = must be a variable.");

+                        tsTerminal.clear();

+                        tsNonTerminal.clear();

+                        return;

+                    }

+                    hVars.insert( *a.sVal, deref( b ) );

+                    tsTerminal.push(

+                        Token( Token::tNumber,

+                            new Number( deref( b ) )

+                            )

+                        );

+                }

+                break;

+

             case Token::tNumber:

-            case Token::tString:

+            case Token::tVariable:

             case Token::tCommand:

             case Token::tEndOfLine:

             case Token::tEndOfInput:

@@ -221,6 +296,7 @@ int Parser::reqTokens( Token::Type eType )
         case Token::tMinus:

         case Token::tDivide:

         case Token::tMultiply:

+        case Token::tEquals:

             return 2;

 

         case Token::tOpenParen:

@@ -239,8 +315,9 @@ int Parser::getPriority( Token::Type eType )
     switch( eType )

     {

         case Token::tNumber:

-        case Token::tString:

+        case Token::tVariable:

         case Token::tCommand:

+        case Token::tEquals:

             return 0;

 

         case Token::tPlus:

@@ -264,3 +341,26 @@ int Parser::getPriority( Token::Type eType )
     }

 }

 

+Number &Parser::deref( Token &t )

+{

+    if( t.eType == Token::tNumber )

+    {

+        return *t.nVal;

+    }

+    else if( t.eType == Token::tVariable )

+    {

+        try

+        {

+            return hVars.get( *t.sVal );

+        }

+        catch(...)

+        {

+            return nZero;

+        }

+    }

+    else

+    {

+        throw Bu::ExceptionBase("Element was not a number or variable.");

+    }

+}

+