117 lines
3.7 KiB
C#
117 lines
3.7 KiB
C#
/*
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* Copyright (c) 2019-2024, Sjofn LLC
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* All rights reserved.
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*
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* - Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* - Redistributions of source code must retain the above copyright notice, this
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* list of conditions and the following disclaimer.
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* - Neither the name of the openmetaverse.co nor the names
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* of its contributors may be used to endorse or promote products derived from
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* this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
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* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
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* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
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* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
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* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
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* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
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* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
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* POSSIBILITY OF SUCH DAMAGE.
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*/
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using System;
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namespace LibreMetaverse.LslTools
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{
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public class Precedence
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{
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public Precedence.PrecType m_type;
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public int m_prec;
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public Precedence m_next;
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public Precedence(Precedence.PrecType t, int p, Precedence next)
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{
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if (Precedence.CheckType(next, t, 0) != 0)
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Console.WriteLine("redeclaration of precedence");
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this.m_next = next;
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this.m_type = t;
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this.m_prec = p;
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}
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private static int CheckType(Precedence p, Precedence.PrecType t, int d)
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{
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if (p == null)
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return 0;
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if (p.m_type == t || p.m_type <= Precedence.PrecType.nonassoc && t <= Precedence.PrecType.nonassoc)
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return p.m_prec;
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return Precedence.Check(p.m_next, t, d + 1);
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}
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public static int Check(Precedence p, Precedence.PrecType t, int d)
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{
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if (p == null)
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return 0;
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if (p.m_type == t)
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return p.m_prec;
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return Precedence.Check(p.m_next, t, d + 1);
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}
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public static int Check(CSymbol s, Production p, int d)
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{
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if (s.m_prec == null)
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return 0;
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int num1 = Precedence.CheckType(s.m_prec, Precedence.PrecType.after, d + 1);
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int num2 = Precedence.CheckType(s.m_prec, Precedence.PrecType.left, d + 1);
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if (num1 > num2)
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return num1 - p.m_prec;
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return num2 - p.m_prec;
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}
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public static void Check(Production p)
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{
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int count = p.m_rhs.Count;
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while (count > 1 && ((SYMBOL) p.m_rhs[count - 1]).IsAction())
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--count;
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switch (count)
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{
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case 2:
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if ((CSymbol) p.m_rhs[0] == p.m_lhs)
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{
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int num = Precedence.Check(((CSymbol) p.m_rhs[1]).m_prec, Precedence.PrecType.after, 0);
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if (num == 0)
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break;
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p.m_prec = num;
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break;
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}
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if ((CSymbol) p.m_rhs[1] != p.m_lhs)
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break;
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int num1 = Precedence.Check(((CSymbol) p.m_rhs[0]).m_prec, Precedence.PrecType.before, 0);
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if (num1 == 0)
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break;
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p.m_prec = num1;
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break;
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case 3:
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int num2 = Precedence.CheckType(((CSymbol) p.m_rhs[1]).m_prec, Precedence.PrecType.left, 0);
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if (num2 == 0 || (CSymbol) p.m_rhs[2] != p.m_lhs)
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break;
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p.m_prec = num2;
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break;
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}
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}
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public enum PrecType
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{
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left,
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right,
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nonassoc,
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before,
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after,
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}
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}
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}
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