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libremetaverse/LibreMetaverse.LslTools/Tools/ProdItem.cs
2024-01-15 14:41:36 -06:00

112 lines
3.4 KiB
C#

/*
* Copyright (c) 2019-2024, Sjofn LLC
* All rights reserved.
*
* - Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* - Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
* - Neither the name of the openmetaverse.co nor the names
* of its contributors may be used to endorse or promote products derived from
* this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
using System;
using System.Collections;
namespace LibreMetaverse.LslTools
{
public class ProdItem
{
public Production m_prod;
public int m_pos;
public bool m_done;
private SymbolSet follow;
public ProdItem(Production prod, int pos)
{
this.m_prod = prod;
this.m_pos = pos;
this.m_done = false;
}
public ProdItem()
{
this.m_prod = (Production) null;
this.m_pos = 0;
this.m_done = false;
}
public CSymbol Next()
{
if (this.m_pos < this.m_prod.m_rhs.Count)
return (CSymbol) this.m_prod.m_rhs[this.m_pos];
return (CSymbol) null;
}
public bool IsReducingAction()
{
if (this.m_pos == this.m_prod.m_rhs.Count - 1)
return this.Next().IsAction();
return false;
}
public SymbolSet FirstOfRest(SymbolsGen syms)
{
if (this.follow != null)
return this.follow;
this.follow = new SymbolSet(syms);
bool flag = false;
int count = this.m_prod.m_rhs.Count;
for (int index = this.m_pos + 1; index < count; ++index)
{
CSymbol rh = (CSymbol) this.m_prod.m_rhs[index];
foreach (CSymbol key in (IEnumerable) rh.m_first.Keys)
this.follow.CheckIn(key);
if (!rh.IsNullable())
{
flag = true;
break;
}
}
if (!flag)
this.follow.Add(this.m_prod.m_lhs.m_follow);
this.follow = this.follow.Resolve();
return this.follow;
}
public void Print()
{
Console.Write(" {0} {1} : ", (object) this.m_prod.m_pno, this.m_prod.m_lhs == null ? (object) "$start" : (object) this.m_prod.m_lhs.yytext);
int index;
for (index = 0; index < this.m_prod.m_rhs.Count; ++index)
{
if (index == this.m_pos)
Console.Write("_");
else
Console.Write(" ");
string str = ((TOKEN) this.m_prod.m_rhs[index]).yytext;
if (str.Equals("\n"))
str = "\\n";
Console.Write(str);
}
if (index == this.m_pos)
Console.Write("_");
Console.Write(" ");
}
}
}