Exemplo n.º 1
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		public ParserReduce(ParserAction action,int depth,Production prod) : base(action) {m_depth=depth; m_prod = prod; }
Exemplo n.º 2
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		public bool Lookback(Production pr,ParseState p) { return new Path(this,pr.Prefix(pr.m_rhs.Count)).Top==this; }
Exemplo n.º 3
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		public ProdItem(Production prod, int pos) 
		{
			m_prod=prod; 
			m_pos=pos; 
			m_done=false; 
		}
Exemplo n.º 4
0
		public Precedence.PrecType ShiftPrecedence(Production prod,ParseState ps) // 4.5h
		{
			if (prod==null) // no reduce available
				return Precedence.PrecType.left; // shift // 4.5h
			if (!((SymbolSet)prod.m_lhs.m_follow).Contains(this)) // if this is not a follow symbol of the prod's lhs, there is no conflict
				return Precedence.PrecType.left; // shift  // 4.5h
			if (m_prec==null) 
			{ // no precedence information
				Console.WriteLine("Shift/Reduce conflict {0} on reduction {1} in state {2}", yytext, prod.m_pno,ps.m_state);
				return Precedence.PrecType.left; // shift anyway // 4.5h
			}
			if (m_prec.m_type==Precedence.PrecType.nonassoc) // 4.5h
				return Precedence.PrecType.nonassoc; // 4.5h
			int p = Precedence.Check(this,prod,0);
			if (p==0) 
			{
				if (Precedence.Check(m_prec,Precedence.PrecType.right,0)!=0) 
				{ // equal precedence but right associative: shift
					return Precedence.PrecType.left; // 4.5h
				}
				return Precedence.PrecType.right; // don't shift // 4.5h
			}
			return (p>0)?Precedence.PrecType.left:Precedence.PrecType.right; // shift if symbol has higher precedence than production, else reduce // 4.5h
		}
Exemplo n.º 5
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		public static void Check(Production p) 
		{
			int efflen = p.m_rhs.Count;
			while (efflen>1 && ((CSymbol)p.m_rhs[efflen-1]).IsAction())
				efflen--;
			if (efflen==3) 
			{
				CSymbol op = (CSymbol)p.m_rhs[1];
				int b = CheckType(op.m_prec, PrecType.left, 0);
				if (b!=0 && ((CSymbol)p.m_rhs[2])==p.m_lhs) 
				 // allow operators such as E : V = E here
					p.m_prec = b;
			} 
			else if (efflen==2) 
			{
				if ((CSymbol)p.m_rhs[0]==p.m_lhs) 
				{
					int aft = Check(((CSymbol)p.m_rhs[1]).m_prec, PrecType.after,0);
					if (aft!=0)
						p.m_prec = aft;
				} 
				else if ((CSymbol)p.m_rhs[1]==p.m_lhs) 
				{
					int bef = Check(((CSymbol)p.m_rhs[0]).m_prec, PrecType.before,0);
					if (bef!=0)
						p.m_prec = bef;
				}
			}
		}
Exemplo n.º 6
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		public static int Check(CSymbol s, Production p, int d) 
		{
			if (s.m_prec==null)
				return 0;
			int a = CheckType(s.m_prec, PrecType.after,d+1);
			int b = CheckType(s.m_prec, PrecType.left,d+1);
			if (a>b)
				return a - p.m_prec;
			else
				return b - p.m_prec;
		}
Exemplo n.º 7
0
 /// <exclude/>
 public ProdItem()
 {
     m_prod = null;
     m_pos = 0;
     m_done=false;
 }