问题
I'm doing a simple task for investigation purposes. The problem is as follows:
- Create an arithmetic expression with variables.
- Build an AST for the expression.
- Send it to the server (using Sockets)
- Calculate an result of the server side and return the results.
Now I can to build a tree. This method doing it:
private readonly Stack<Expression> expressionStack = new Stack<Expression>();
private readonly Stack<Symbol> operatorStack = new Stack<Symbol>();
private readonly List<string> parameters = new List<string>();
public Expression<Func<decimal[], decimal>> Parse(string expression)
{
if (string.IsNullOrWhiteSpace(expression))
{
return s => 0;
}
var arrayParameter = Expression.Parameter(typeof(decimal[]), "args");
parameters.Clear();
operatorStack.Clear();
expressionStack.Clear();
using (var reader = new StringReader(expression))
{
int peek;
while ((peek = reader.Peek()) > -1)
{
var next = (char)peek;
if (char.IsDigit(next))
{
expressionStack.Push(ReadOperand(reader));
continue;
}
if (char.IsLetter(next))
{
expressionStack.Push(ReadParameter(reader, arrayParameter));
continue;
}
if (Operation.IsDefined(next))
{
if (next == '-' && expressionStack.Count == 0)
{
reader.Read();
operatorStack.Push(Operation.UnaryMinus);
continue;
}
var currentOperation = ReadOperation(reader);
EvaluateWhile(() => operatorStack.Count > 0 && operatorStack.Peek() != Parentheses.Left &&
currentOperation.Precedence <= ((Operation)operatorStack.Peek()).Precedence);
operatorStack.Push(currentOperation);
continue;
}
if (next == '(')
{
reader.Read();
operatorStack.Push(Parentheses.Left);
if (reader.Peek() == '-')
{
reader.Read();
operatorStack.Push(Operation.UnaryMinus);
}
continue;
}
if (next == ')')
{
reader.Read();
EvaluateWhile(() => operatorStack.Count > 0 && operatorStack.Peek() != Parentheses.Left);
operatorStack.Pop();
continue;
}
if (next == ' ')
{
reader.Read();
}
else
{
throw new ArgumentException(string.Format("Encountered invalid character {0}", next),
"expression");
}
}
}
EvaluateWhile(() => operatorStack.Count > 0);
return Expression.Lambda<Func<decimal[], decimal>>(expressionStack.Pop(), arrayParameter);
}
This method works, and returns the expected result.
Before being sent to the server I want to serialize a tree to binary type. My question is as follows. Which is the simplest way I can apply for this?
I found a lot of solutions for LINQ serialization, but they are too big. I don't need the full functionality of these solutions. In addition, usually, they provide the JSON or XML-serialization, but I need a binary serialization.
Can somebody suggest a simple and easy solution for this problem?
来源:https://stackoverflow.com/questions/41871706/serialize-arithmetic-expression-tree