Precedence.cs :  » Script » IronRuby » gpcc » C# / CSharp Open Source

// Copyright (c) Microsoft Corporation. All rights reserved.


using System;


namespace gpcc{
  public enum PrecType { left, right, nonassoc };
 
  public class Precedence
  {
    public PrecType type;
    public int prec;

    public Precedence(PrecType type, int prec)
    {
      this.type = type;
      this.prec = prec;
    }

    public static void Calculate(Production p)
    {
      // Precedence of a production is that of its rightmost terminal
      // unless explicitly labelled with %prec

      if (p.prec == null)
        for (int i = p.rhs.Count - 1; i >= 0; i--)
          if (p.rhs[i] is Terminal)
          {
            p.prec = ((Terminal)p.rhs[i]).prec;
            break;
          }
    }
  }
}