internal void AddChild(RegexNode newChild)
{
RegexNode reducedChild;
if (_children == null)
{
_children = new List <RegexNode>(4);
}
reducedChild = newChild.Reduce();
_children.Add(reducedChild);
reducedChild._next = this;
}
/// <summary>
/// The main RegexCode generator. It does a depth-first walk
/// through the tree and calls EmitFragment to emits code before
/// and after each child of an interior node, and at each leaf.
/// </summary>
private void EmitFragment(int nodetype, RegexNode node, int curIndex)
{
int bits = 0;
if (nodetype <= RegexNode.Ref)
{
if (node.UseOptionR())
{
bits |= RegexCode.Rtl;
}
if ((node._options & RegexOptions.IgnoreCase) != 0)
{
bits |= RegexCode.Ci;
}
}
switch (nodetype)
{
case RegexNode.Concatenate | BeforeChild:
case RegexNode.Concatenate | AfterChild:
case RegexNode.Empty:
break;
case RegexNode.Alternate | BeforeChild:
if (curIndex < node._children.Count - 1)
{
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
}
break;
case RegexNode.Alternate | AfterChild:
{
if (curIndex < node._children.Count - 1)
{
int LBPos = PopInt();
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
PatchJump(LBPos, CurPos());
}
else
{
int I;
for (I = 0; I < curIndex; I++)
{
PatchJump(PopInt(), CurPos());
}
}
break;
}
case RegexNode.Testref | BeforeChild:
switch (curIndex)
{
case 0:
Emit(RegexCode.Setjump);
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
Emit(RegexCode.Testref, MapCapnum(node._m));
Emit(RegexCode.Forejump);
break;
}
break;
case RegexNode.Testref | AfterChild:
switch (curIndex)
{
case 0:
{
int Branchpos = PopInt();
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
PatchJump(Branchpos, CurPos());
Emit(RegexCode.Forejump);
if (node._children.Count > 1)
{
break;
}
// else fallthrough
goto case 1;
}
case 1:
PatchJump(PopInt(), CurPos());
break;
}
break;
case RegexNode.Testgroup | BeforeChild:
switch (curIndex)
{
case 0:
Emit(RegexCode.Setjump);
Emit(RegexCode.Setmark);
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
break;
}
break;
case RegexNode.Testgroup | AfterChild:
switch (curIndex)
{
case 0:
Emit(RegexCode.Getmark);
Emit(RegexCode.Forejump);
break;
case 1:
int Branchpos = PopInt();
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
PatchJump(Branchpos, CurPos());
Emit(RegexCode.Getmark);
Emit(RegexCode.Forejump);
if (node._children.Count > 2)
{
break;
}
// else fallthrough
goto case 2;
case 2:
PatchJump(PopInt(), CurPos());
break;
}
break;
case RegexNode.Loop | BeforeChild:
case RegexNode.Lazyloop | BeforeChild:
if (node._n < int.MaxValue || node._m > 1)
{
Emit(node._m == 0 ? RegexCode.Nullcount : RegexCode.Setcount, node._m == 0 ? 0 : 1 - node._m);
}
else
{
Emit(node._m == 0 ? RegexCode.Nullmark : RegexCode.Setmark);
}
if (node._m == 0)
{
PushInt(CurPos());
Emit(RegexCode.Goto, 0);
}
PushInt(CurPos());
break;
case RegexNode.Loop | AfterChild:
case RegexNode.Lazyloop | AfterChild:
{
int StartJumpPos = CurPos();
int Lazy = (nodetype - (RegexNode.Loop | AfterChild));
if (node._n < int.MaxValue || node._m > 1)
{
Emit(RegexCode.Branchcount + Lazy, PopInt(), node._n == int.MaxValue ? int.MaxValue : node._n - node._m);
}
else
{
Emit(RegexCode.Branchmark + Lazy, PopInt());
}
if (node._m == 0)
{
PatchJump(PopInt(), StartJumpPos);
}
}
break;
case RegexNode.Group | BeforeChild:
case RegexNode.Group | AfterChild:
break;
case RegexNode.Capture | BeforeChild:
Emit(RegexCode.Setmark);
break;
case RegexNode.Capture | AfterChild:
Emit(RegexCode.Capturemark, MapCapnum(node._m), MapCapnum(node._n));
break;
case RegexNode.Require | BeforeChild:
// NOTE: the following line causes lookahead/lookbehind to be
// NON-BACKTRACKING. It can be commented out with (*)
Emit(RegexCode.Setjump);
Emit(RegexCode.Setmark);
break;
case RegexNode.Require | AfterChild:
Emit(RegexCode.Getmark);
// NOTE: the following line causes lookahead/lookbehind to be
// NON-BACKTRACKING. It can be commented out with (*)
Emit(RegexCode.Forejump);
break;
case RegexNode.Prevent | BeforeChild:
Emit(RegexCode.Setjump);
PushInt(CurPos());
Emit(RegexCode.Lazybranch, 0);
break;
case RegexNode.Prevent | AfterChild:
Emit(RegexCode.Backjump);
PatchJump(PopInt(), CurPos());
Emit(RegexCode.Forejump);
break;
case RegexNode.Greedy | BeforeChild:
Emit(RegexCode.Setjump);
break;
case RegexNode.Greedy | AfterChild:
Emit(RegexCode.Forejump);
break;
case RegexNode.One:
case RegexNode.Notone:
Emit(node._type | bits, node._ch);
break;
case RegexNode.Notoneloop:
case RegexNode.Notonelazy:
case RegexNode.Oneloop:
case RegexNode.Onelazy:
if (node._m > 0)
{
Emit(((node._type == RegexNode.Oneloop || node._type == RegexNode.Onelazy) ?
RegexCode.Onerep : RegexCode.Notonerep) | bits, node._ch, node._m);
}
if (node._n > node._m)
{
Emit(node._type | bits, node._ch, node._n == int.MaxValue ?
int.MaxValue : node._n - node._m);
}
break;
case RegexNode.Setloop:
case RegexNode.Setlazy:
if (node._m > 0)
{
Emit(RegexCode.Setrep | bits, StringCode(node._str), node._m);
}
if (node._n > node._m)
{
Emit(node._type | bits, StringCode(node._str),
(node._n == int.MaxValue) ? int.MaxValue : node._n - node._m);
}
break;
case RegexNode.Multi:
Emit(node._type | bits, StringCode(node._str));
break;
case RegexNode.Set:
Emit(node._type | bits, StringCode(node._str));
break;
case RegexNode.Ref:
Emit(node._type | bits, MapCapnum(node._m));
break;
case RegexNode.Nothing:
case RegexNode.Bol:
case RegexNode.Eol:
case RegexNode.Boundary:
case RegexNode.Nonboundary:
case RegexNode.ECMABoundary:
case RegexNode.NonECMABoundary:
case RegexNode.Beginning:
case RegexNode.Start:
case RegexNode.EndZ:
case RegexNode.End:
Emit(node._type);
break;
default:
throw new ArgumentException("");
}
}
/*
* This is a related computation: it takes a RegexTree and computes the
* leading substring if it see one. It's quite trivial and gives up easily.
*/
internal static RegexPrefix Prefix(RegexTree tree)
{
RegexNode curNode;
RegexNode concatNode = null;
int nextChild = 0;
curNode = tree._root;
for (; ;)
{
switch (curNode._type)
{
case RegexNode.Concatenate:
if (curNode.ChildCount() > 0)
{
concatNode = curNode;
nextChild = 0;
}
break;
case RegexNode.Greedy:
case RegexNode.Capture:
curNode = curNode.Child(0);
concatNode = null;
continue;
case RegexNode.Oneloop:
case RegexNode.Onelazy:
if (curNode._m > 0)
{
string pref = string.Empty.PadRight(curNode._m, curNode._ch);
return(new RegexPrefix(pref, 0 != (curNode._options & RegexOptions.IgnoreCase)));
}
else
{
return(RegexPrefix.Empty);
}
case RegexNode.One:
return(new RegexPrefix(curNode._ch.ToString(), 0 != (curNode._options & RegexOptions.IgnoreCase)));
case RegexNode.Multi:
return(new RegexPrefix(curNode._str, 0 != (curNode._options & RegexOptions.IgnoreCase)));
case RegexNode.Bol:
case RegexNode.Eol:
case RegexNode.Boundary:
case RegexNode.ECMABoundary:
case RegexNode.Beginning:
case RegexNode.Start:
case RegexNode.EndZ:
case RegexNode.End:
case RegexNode.Empty:
case RegexNode.Require:
case RegexNode.Prevent:
break;
default:
return(RegexPrefix.Empty);
}
if (concatNode == null || nextChild >= concatNode.ChildCount())
{
return(RegexPrefix.Empty);
}
curNode = concatNode.Child(nextChild++);
}
}
/*
* FC computation and shortcut cases for each node type
*/
private void CalculateFC(int NodeType, RegexNode node, int CurIndex)
{
bool ci = false;
bool rtl = false;
if (NodeType <= RegexNode.Ref)
{
if ((node._options & RegexOptions.IgnoreCase) != 0)
{
ci = true;
}
if ((node._options & RegexOptions.RightToLeft) != 0)
{
rtl = true;
}
}
switch (NodeType)
{
case RegexNode.Concatenate | BeforeChild:
case RegexNode.Alternate | BeforeChild:
case RegexNode.Testref | BeforeChild:
case RegexNode.Loop | BeforeChild:
case RegexNode.Lazyloop | BeforeChild:
break;
case RegexNode.Testgroup | BeforeChild:
if (CurIndex == 0)
{
SkipChild();
}
break;
case RegexNode.Empty:
PushFC(new RegexFC(true));
break;
case RegexNode.Concatenate | AfterChild:
if (CurIndex != 0)
{
RegexFC child = PopFC();
RegexFC cumul = TopFC();
_failed = !cumul.AddFC(child, true);
}
if (!TopFC()._nullable)
{
_skipAllChildren = true;
}
break;
case RegexNode.Testgroup | AfterChild:
if (CurIndex > 1)
{
RegexFC child = PopFC();
RegexFC cumul = TopFC();
_failed = !cumul.AddFC(child, false);
}
break;
case RegexNode.Alternate | AfterChild:
case RegexNode.Testref | AfterChild:
if (CurIndex != 0)
{
RegexFC child = PopFC();
RegexFC cumul = TopFC();
_failed = !cumul.AddFC(child, false);
}
break;
case RegexNode.Loop | AfterChild:
case RegexNode.Lazyloop | AfterChild:
if (node._m == 0)
{
TopFC()._nullable = true;
}
break;
case RegexNode.Group | BeforeChild:
case RegexNode.Group | AfterChild:
case RegexNode.Capture | BeforeChild:
case RegexNode.Capture | AfterChild:
case RegexNode.Greedy | BeforeChild:
case RegexNode.Greedy | AfterChild:
break;
case RegexNode.Require | BeforeChild:
case RegexNode.Prevent | BeforeChild:
SkipChild();
PushFC(new RegexFC(true));
break;
case RegexNode.Require | AfterChild:
case RegexNode.Prevent | AfterChild:
break;
case RegexNode.One:
case RegexNode.Notone:
PushFC(new RegexFC(node._ch, NodeType == RegexNode.Notone, false, ci));
break;
case RegexNode.Oneloop:
case RegexNode.Onelazy:
PushFC(new RegexFC(node._ch, false, node._m == 0, ci));
break;
case RegexNode.Notoneloop:
case RegexNode.Notonelazy:
PushFC(new RegexFC(node._ch, true, node._m == 0, ci));
break;
case RegexNode.Multi:
if (node._str.Length == 0)
{
PushFC(new RegexFC(true));
}
else if (!rtl)
{
PushFC(new RegexFC(node._str[0], false, false, ci));
}
else
{
PushFC(new RegexFC(node._str[node._str.Length - 1], false, false, ci));
}
break;
case RegexNode.Set:
PushFC(new RegexFC(node._str, false, ci));
break;
case RegexNode.Setloop:
case RegexNode.Setlazy:
PushFC(new RegexFC(node._str, node._m == 0, ci));
break;
case RegexNode.Ref:
PushFC(new RegexFC(RegexCharClass.AnyClass, true, false));
break;
case RegexNode.Nothing:
case RegexNode.Bol:
case RegexNode.Eol:
case RegexNode.Boundary:
case RegexNode.Nonboundary:
case RegexNode.ECMABoundary:
case RegexNode.NonECMABoundary:
case RegexNode.Beginning:
case RegexNode.Start:
case RegexNode.EndZ:
case RegexNode.End:
PushFC(new RegexFC(true));
break;
default:
throw new ArgumentException("");
}
}