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

306 lines
8.9 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 Dfa : LNode
{
public Hashtable m_map = new Hashtable();
public string m_tokClass = "";
public int m_reswds = -1;
internal NList m_nfa = new NList();
private YyLexer m_tokens;
public Dfa.Action m_actions;
private Dfa()
{
}
public Dfa(TokensGen tks)
: base(tks)
{
this.m_tokens = tks.m_tokens;
}
public Dfa(Nfa nfa)
: base(nfa.m_tks)
{
this.m_tokens = this.m_tks.m_tokens;
this.AddNfaNode((NfaNode) nfa);
this.Closure();
this.AddActions();
}
public static void SetTokens(YyLexer tks, Hashtable h)
{
foreach (Dfa dfa in (IEnumerable) h.Values)
{
if (dfa.m_tokens == null)
{
dfa.m_tokens = tks;
Dfa.SetTokens(tks, dfa.m_map);
}
}
}
private void AddAction(int act)
{
this.m_actions = new Dfa.Action(act, this.m_actions);
}
private void MakeLastAction(int act)
{
while (this.m_actions != null && this.m_actions.a_act >= act)
this.m_actions = this.m_actions.a_next;
this.AddAction(act);
}
internal bool AddNfaNode(NfaNode nfa)
{
if (!this.m_nfa.Add(nfa))
return false;
if (nfa.m_sTerminal != "")
{
int length = 0;
string str1 = "";
string sTerminal = nfa.m_sTerminal;
if (sTerminal[0] == '%')
{
length = 0;
int index = 1;
while (index < sTerminal.Length && (sTerminal[index] != ' ' && sTerminal[index] != '\t') && (sTerminal[index] != '\n' && sTerminal[index] != '{' && sTerminal[index] != ':'))
{
++index;
++length;
}
str1 = nfa.m_sTerminal.Substring(1, length);
}
if (length > 0 && length + 1 < sTerminal.Length)
{
string str2 = nfa.m_sTerminal.Substring(length + 1).Trim();
if (str2.Length > 0 && str2.StartsWith("%except"))
{
this.m_reswds = nfa.m_state;
this.m_tks.m_tokens.reswds[(object) nfa.m_state] = (object) ResWds.New(this.m_tks, str2.Substring(7));
}
}
if (str1 == "")
{
if (this.m_tokClass == "" || this.m_actions.a_act > nfa.m_state)
this.AddAction(nfa.m_state);
}
else if (this.m_actions == null || this.m_actions.a_act > nfa.m_state)
{
this.MakeLastAction(nfa.m_state);
this.m_tokClass = str1;
}
}
return true;
}
internal void AddActions()
{
this.m_tks.states.Add((object) this);
foreach (Charset charset in (IEnumerable) this.m_tks.m_tokens.cats.Values)
{
foreach (char key in (IEnumerable) charset.m_chars.Keys)
{
Dfa dfa = this.Target(key);
if (dfa != null)
this.m_map[(object) key] = (object) dfa;
}
}
}
internal Dfa Target(char ch)
{
Dfa dfa = new Dfa(this.m_tks);
for (NList nlist = this.m_nfa; !nlist.AtEnd; nlist = nlist.m_next)
nlist.m_node.AddTarget(ch, dfa);
if (dfa.m_nfa.AtEnd)
return (Dfa) null;
dfa.Closure();
foreach (var t in this.m_tks.states)
{
if (((Dfa) t).SameAs(dfa))
return (Dfa) t;
}
dfa.AddActions();
return dfa;
}
private void Closure()
{
for (NList nlist = this.m_nfa; !nlist.AtEnd; nlist = nlist.m_next)
this.ClosureAdd(nlist.m_node);
}
private void ClosureAdd(NfaNode nfa)
{
foreach (var t in nfa.m_eps)
{
NfaNode ep = (NfaNode) t;
if (this.AddNfaNode(ep))
this.ClosureAdd(ep);
}
}
internal bool SameAs(Dfa dfa)
{
NList nlist1 = this.m_nfa;
NList nlist2;
for (nlist2 = dfa.m_nfa; nlist1.m_node == nlist2.m_node && !nlist1.AtEnd; nlist2 = nlist2.m_next)
nlist1 = nlist1.m_next;
return nlist1.m_node == nlist2.m_node;
}
public int Match(string str, int ix, ref int action)
{
Dfa dfa;
int num;
if (ix < str.Length && (dfa = (Dfa) this.m_map[(object) this.m_tokens.Filter(str[ix])]) != null && (num = dfa.Match(str, ix + 1, ref action)) >= 0)
return num + 1;
if (this.m_actions == null)
return -1;
action = this.m_actions.a_act;
return 0;
}
public void Print()
{
Console.Write("{0}:", (object) this.m_state);
if (this.m_actions != null)
{
Console.Write(" (");
for (Dfa.Action action = this.m_actions; action != null; action = action.a_next)
Console.Write("{0} <", (object) action.a_act);
if (this.m_tokClass != "")
Console.Write(this.m_tokClass);
Console.Write(">)");
}
Console.WriteLine();
Hashtable hashtable = new Hashtable();
IDictionaryEnumerator enumerator1 = this.m_map.GetEnumerator();
int count = this.m_map.Count;
while (count-- > 0)
{
enumerator1.MoveNext();
char key1 = (char) enumerator1.Key;
Dfa dfa1 = (Dfa) enumerator1.Value;
if (!hashtable.Contains((object) key1))
{
hashtable[(object) key1] = (object) true;
Console.Write(" {0} ", (object) dfa1.m_state);
int num1 = (int) key1;
if (num1 >= 32 && num1 < 128)
Console.Write(key1);
else
Console.Write(" #{0} ", (object) num1);
IDictionaryEnumerator enumerator2 = this.m_map.GetEnumerator();
do
{
enumerator2.MoveNext();
}
while ((Dfa) enumerator2.Value != dfa1);
for (int index = count; index > 0; --index)
{
enumerator2.MoveNext();
char key2 = (char) enumerator2.Key;
Dfa dfa2 = (Dfa) enumerator2.Value;
if (dfa1 == dfa2)
{
hashtable[(object) key2] = (object) true;
int num2 = (int) key2;
if (num2 >= 32 && num2 < 128)
Console.Write(key2);
else
Console.Write(" #{0} ", (object) num2);
}
}
Console.WriteLine();
}
}
}
public static object Serialise(object o, Serialiser s)
{
if (s == null)
return (object) new Dfa();
Dfa dfa = (Dfa) o;
if (s.Encode)
{
s.Serialise((object) dfa.m_state);
s.Serialise((object) dfa.m_map);
s.Serialise((object) dfa.m_actions);
s.Serialise((object) dfa.m_tokClass);
s.Serialise((object) dfa.m_reswds);
return (object) null;
}
dfa.m_state = (int) s.Deserialise();
dfa.m_map = (Hashtable) s.Deserialise();
dfa.m_actions = (Dfa.Action) s.Deserialise();
dfa.m_tokClass = (string) s.Deserialise();
dfa.m_reswds = (int) s.Deserialise();
return (object) dfa;
}
public class Action
{
public int a_act;
public Dfa.Action a_next;
public Action(int act, Dfa.Action next)
{
this.a_act = act;
this.a_next = next;
}
private Action()
{
}
public static object Serialise(object o, Serialiser s)
{
if (s == null)
return (object) new Dfa.Action();
Dfa.Action action = (Dfa.Action) o;
if (s.Encode)
{
s.Serialise((object) action.a_act);
s.Serialise((object) action.a_next);
return (object) null;
}
action.a_act = (int) s.Deserialise();
action.a_next = (Dfa.Action) s.Deserialise();
return (object) action;
}
}
}
}