From 04f56c12e82ea5228b2b65e68c46ed7f4563182b Mon Sep 17 00:00:00 2001
From: Mike Buland <mike@xagasoft.com>
Date: Tue, 23 Apr 2013 11:47:01 -0600
Subject: Variables work.
---
src/lexer.cpp | 40 ++++++++++----------
src/parser.cpp | 114 +++++++++++++++++++++++++++++++++++++++++++++++++++++----
src/parser.h | 6 +++
src/token.cpp | 5 ++-
src/token.h | 3 +-
5 files changed, 138 insertions(+), 30 deletions(-)
(limited to 'src')
diff --git a/src/lexer.cpp b/src/lexer.cpp
index 3ebb0cf..46686c8 100644
--- a/src/lexer.cpp
+++ b/src/lexer.cpp
@@ -63,6 +63,26 @@ Token Lexer::nextToken()
}
break;
+ case '$':
+ {
+ Bu::String *sTmp = new Bu::String();
+ for( iBufPos++; iBufPos < sBuf.getSize() &&
+ sBuf[iBufPos] != ' ' && sBuf[iBufPos] != '\t' &&
+ sBuf[iBufPos] != '+' && sBuf[iBufPos] != '-' &&
+ sBuf[iBufPos] != '*' && sBuf[iBufPos] != '/' &&
+ sBuf[iBufPos] != '(' && sBuf[iBufPos] != ')';
+ iBufPos++ )
+ {
+ sTmp->append( sBuf[iBufPos] );
+ }
+ return Token( Token::tVariable, sTmp );
+ }
+ break;
+
+ case '=':
+ iBufPos++;
+ return Token( Token::tEquals );
+
case '+':
iBufPos++;
return Token( Token::tPlus );
@@ -115,26 +135,6 @@ Token Lexer::nextToken()
delete sTmp;
return Token( Token::tNumber, n );
}
- else if( (sBuf[iBufPos]>=(ascRangeTop+1) && sBuf[iBufPos]<='z') ||
- (sBuf[iBufPos]>='A' && sBuf[iBufPos]<='Z') ||
- sBuf[iBufPos] == '_' )
- {
- for( ; iBufPos < sBuf.getSize(); iBufPos++ )
- {
- if( (sBuf[iBufPos]>='a' && sBuf[iBufPos]<='z') ||
- (sBuf[iBufPos]>='A' && sBuf[iBufPos]<='Z') ||
- (sBuf[iBufPos]>='0' && sBuf[iBufPos]<='9') ||
- sBuf[iBufPos] == '_' )
- {
- sTmp->append( sBuf[iBufPos] );
- }
- else
- {
- break;
- }
- }
- return Token( Token::tString, sTmp );
- }
else
{
sBuf.clear();
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.");
+ }
+}
+
diff --git a/src/parser.h b/src/parser.h
index 5563613..2b1a4af 100644
--- a/src/parser.h
+++ b/src/parser.h
@@ -2,7 +2,9 @@
#define PARSER_H
#include <bu/list.h>
+#include <bu/hash.h>
#include "token.h"
+#include "number.h"
namespace Bu
{
@@ -23,13 +25,17 @@ private:
void unwind();
int reqTokens( Token::Type eType );
int getPriority( Token::Type eType );
+ Number &deref( Token &t );
private:
Lexer &lex;
Bu::Stream &rOut;
typedef Bu::List<Token> TokenStack;
+ typedef Bu::Hash<Bu::String, Number> VarHash;
TokenStack tsTerminal;
TokenStack tsNonTerminal;
+ Number nZero;
+ VarHash hVars;
};
#endif
diff --git a/src/token.cpp b/src/token.cpp
index d7fbe88..019e54d 100644
--- a/src/token.cpp
+++ b/src/token.cpp
@@ -38,7 +38,7 @@ Token::~Token()
delete nVal;
break;
- case tString:
+ case tVariable:
case tCommand:
delete sVal;
break;
@@ -53,7 +53,7 @@ Bu::Formatter &operator<<( Bu::Formatter &f, Token::Type eType )
switch( eType )
{
case Token::tNumber: return f << "num";
- case Token::tString: return f << "str";
+ case Token::tVariable: return f << "var";
case Token::tCommand: return f << "cmd";
case Token::tPlus: return f << "+";
case Token::tMinus: return f << "-";
@@ -61,6 +61,7 @@ Bu::Formatter &operator<<( Bu::Formatter &f, Token::Type eType )
case Token::tMultiply: return f << "*";
case Token::tOpenParen: return f << "(";
case Token::tCloseParen: return f << ")";
+ case Token::tEquals: return f << "=";
case Token::tEndOfLine: return f << "eol";
case Token::tEndOfInput: return f << "eoi";
diff --git a/src/token.h b/src/token.h
index 3b5caff..05a610a 100644
--- a/src/token.h
+++ b/src/token.h
@@ -14,7 +14,7 @@ public:
enum Type
{
tNumber,
- tString,
+ tVariable,
tCommand,
tPlus,
tMinus,
@@ -22,6 +22,7 @@ public:
tMultiply,
tOpenParen,
tCloseParen,
+ tEquals,
tEndOfLine,
--
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