public void CreateBinaryExpression()
{
IExpression leftExpression = new ConstantExpression(1);
IExpression rightExpression = new ConstantExpression(2);
BinaryExpression expression = new ArithmeticBinaryExpression(ArithmeticOperator.Add, leftExpression, rightExpression);
Assert.IsTrue(expression.LeftExpression == leftExpression);
Assert.IsTrue(expression.RightExpression == rightExpression);
}
private static object EvaluateArithmeticBinaryOperator(ArithmeticOperator operation, object left, object right)
{
IExpression expression = new ArithmeticBinaryExpression(operation, new ConstantExpression(left), new ConstantExpression(right));
return expression.Evaluate(null);
}
private IExpression ParseBinaryExpressionLevelMultiply()
{
IExpression expression = this.ParseBinaryExpressionLevelAdd();
if (expression == null)
return null;
Token token = this.NextToken();
while (token != null && token.Type == TokenType.Operator && (token.Value == "*" || token.Value == "/"))
{
ArithmeticOperator oper = token.Value == "*" ? ArithmeticOperator.Multiply : ArithmeticOperator.Divide;
expression = new ArithmeticBinaryExpression(oper, expression, this.ParseBinaryExpressionLevelAdd());
token = this.NextToken();
}
if (token != null)
this.PushToken(token);
return expression;
}
private IExpression ParseStringInterpolation(string text)
{
IList<IExpression> expressions = new List<IExpression>();
while (true)
{
int pos = text.IndexOf('$');
if (pos < 0)
{
if (!string.IsNullOrEmpty(text))
{
IExpression textexpr = new ConstantExpression(text);
expressions.Add(textexpr);
}
break;
}
if (pos == text.Length - 1)
throw new ParserException("Unexpected End of String");
string left = text.Substring(0, pos);
if (!string.IsNullOrEmpty(left))
expressions.Add(new ConstantExpression(left));
if (text[pos + 1] == '{')
{
int pos2 = text.IndexOf('}', pos + 1);
if (pos2 < 0)
throw new ParserException("Unexpected End of String");
string subtext = text.Substring(pos + 2, pos2 - pos - 2);
text = text.Substring(pos2 + 1);
Parser parser = new Parser(subtext);
IExpression newexpr = parser.ParseExpression();
if (parser.ParseExpression() != null)
throw new ParserException("Bad String Interpolation");
expressions.Add(newexpr);
}
else if (char.IsLetter(text[pos + 1]))
{
Parser parser = new Parser(text.Substring(pos + 1));
string name = parser.ParseName();
IExpression varexpr = new VariableExpression(name);
expressions.Add(varexpr);
text = text.Substring(pos + name.Length + 1);
}
else
throw new ParserException("Bad String Interpolation");
}
if (expressions.Count == 1)
return expressions[0];
IExpression expression = expressions[0];
foreach (var expr in expressions.Skip(1))
expression = new ArithmeticBinaryExpression(ArithmeticOperator.Add, expression, expr);
return expression;
}
private IExpression ParseBinaryExpressionLevelAdd()
{
IExpression expression = this.ParseDotExpression();
if (expression == null)
return null;
Token token = this.NextToken();
while (token != null && token.Type == TokenType.Operator && (token.Value == "+" || token.Value == "-"))
{
ArithmeticOperator oper = token.Value == "+" ? ArithmeticOperator.Add : ArithmeticOperator.Subtract;
expression = new ArithmeticBinaryExpression(oper, expression, this.ParseDotExpression());
token = this.NextToken();
}
if (token != null)
this.PushToken(token);
return expression;
}