public LiteralExpression parseLiteralExpression()
{
LiteralExpression lit;
switch (currentToken.type)
{
case Token.TokenValue.STRING:
case Token.TokenValue.CHAR:
case Token.TokenValue.INT:
case Token.TokenValue.BOOLEAN:
lit = new LiteralExpression(currentToken);
nextToken();
return lit;
default:
throw new UndefinedException(lineNumber, colNumber);
}
}
public ObjectExpression evalSimpleExpression(SimpleExpression exp)
{
if (exp is LiteralExpression)
{
lit = (LiteralExpression)exp;
switch (lit.value.type)
{
case ParserUtils.Token.TokenValue.STRING:
return new ObjectExpression(ObjectType.stringType, lit.value.stringValue);
case ParserUtils.Token.TokenValue.INT:
return new ObjectExpression(ObjectType.intType, lit.value.intValue);
case ParserUtils.Token.TokenValue.CHAR:
return new ObjectExpression(ObjectType.charType, lit.value.charValue);
case ParserUtils.Token.TokenValue.BOOLEAN:
return new ObjectExpression(ObjectType.booleanType, lit.value.booleanValue);
default:
break;
}
}
else if (exp is SubSimpleExpression)
{
return evalSimpleExpression(((SubSimpleExpression)exp).exp);
}
else if (exp is NullExpression)
{
return null;
}
else if (exp is BinaryOperatorExpression)
{
BinaryOperatorExpression binExp = (BinaryOperatorExpression)exp;
ObjectExpression oLeft = evalSimpleExpression(binExp.e1), oRight;
switch (binExp.op)
{
case ParserUtils.Token.TokenValue.AND:
if ((bool)oLeft.value)
{
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.booleanType, (bool)oRight.value);
}
return new ObjectExpression(ObjectType.booleanType, false);
case ParserUtils.Token.TokenValue.OR:
if ((bool)oLeft.value)
{
return new ObjectExpression(ObjectType.booleanType, true);
}
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.booleanType, (bool)oRight.value);
case ParserUtils.Token.TokenValue.PLUS:
oRight = evalSimpleExpression(binExp.e2);
if (oLeft.type == ObjectType.stringType || oRight.type == ObjectType.stringType)
{
return new ObjectExpression(ObjectType.stringType, oLeft.value.ToString() + oRight.value.ToString());
}
if (oLeft.type == ObjectType.intType && oRight.type == ObjectType.intType)
{
return new ObjectExpression(ObjectType.intType, (int)oLeft.value + (int)oRight.value);
}
break;
case ParserUtils.Token.TokenValue.MINUS:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.intType, (int)oLeft.value - (int)oRight.value);
case ParserUtils.Token.TokenValue.TIMES:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.intType, (int)oLeft.value * (int)oRight.value);
case ParserUtils.Token.TokenValue.DIV:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.intType, (int)oLeft.value / (int)oRight.value);
case ParserUtils.Token.TokenValue.LT:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.booleanType, (int)oLeft.value < (int)oRight.value);
case ParserUtils.Token.TokenValue.GT:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.booleanType, (int)oLeft.value > (int)oRight.value);
case ParserUtils.Token.TokenValue.LEQ:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.booleanType, (int)oLeft.value <= (int)oRight.value);
case ParserUtils.Token.TokenValue.GEQ:
oRight = evalSimpleExpression(binExp.e2);
return new ObjectExpression(ObjectType.booleanType, (int)oLeft.value >= (int)oRight.value);
case ParserUtils.Token.TokenValue.EQBOOL:
oRight = evalSimpleExpression(binExp.e2);
if (oLeft.type == ObjectType.intType)
{
return new ObjectExpression(ObjectType.booleanType, (int)oLeft.value == (int)oRight.value);
}
if (oLeft.type == ObjectType.stringType)
{
return new ObjectExpression(ObjectType.booleanType, ((string)oLeft.value).Equals((string)oRight.value));
}
if (oLeft.type == ObjectType.booleanType)
{
return new ObjectExpression(ObjectType.booleanType, (bool)oLeft.value == (bool)oRight.value);
}
if (oLeft.type == ObjectType.charType)
{
return new ObjectExpression(ObjectType.booleanType, (char)oLeft.value == (char)oRight.value);
}
break;
default:
break;
}
}
else if (exp is UnaryOperatorExpression)
{
unExp = (UnaryOperatorExpression)exp;
switch (unExp.op)
{
case ParserUtils.Token.TokenValue.NEG:
o1 = evalSimpleExpression(((UnaryOperatorExpression)exp).exp);
return new ObjectExpression(ObjectType.booleanType, !((bool)o1.value));
}
}
else if (exp is VariableExpression)
{
return variables[((VariableExpression)exp).name];
}
else if (exp is CharacterVariableExpression)
{
return new ObjectExpression(ObjectType.intType, IrisData.getPlayerVariable(((CharacterVariableExpression)exp).name));
}
return null;
}
public CaseExpression(LiteralExpression literalValue, Expression bodyExp)
{
this.literal = literalValue;
}
