| static private IsMergeable ( string charClass ) : bool | ||
| charClass | string | |
| return | bool | |
/*
* ReduceAlternation:
*
* Basic optimization. Single-letter alternations can be replaced
* by faster set specifications, and nested alternations with no
* intervening operators can be flattened:
*
* a|b|c|def|g|h -> [a-c]|def|[gh]
* apple|(?:orange|pear)|grape -> apple|orange|pear|grape
*/
internal RegexNode ReduceAlternation()
{
// Combine adjacent sets/chars
bool wasLastSet;
bool lastNodeCannotMerge;
RegexOptions optionsLast;
RegexOptions optionsAt;
int i;
int j;
RegexNode at;
RegexNode prev;
if (_children == null)
{
return(new RegexNode(RegexNode.Nothing, _options));
}
wasLastSet = false;
lastNodeCannotMerge = false;
optionsLast = 0;
for (i = 0, j = 0; i < _children.Count; i++, j++)
{
at = _children[i];
if (j < i)
{
_children[j] = at;
}
for (; ;)
{
if (at._type == Alternate)
{
for (int k = 0; k < at._children.Count; k++)
{
at._children[k]._next = this;
}
_children.InsertRange(i + 1, at._children);
j--;
}
else if (at._type == Set || at._type == One)
{
// Cannot merge sets if L or I options differ, or if either are negated.
optionsAt = at._options & (RegexOptions.RightToLeft | RegexOptions.IgnoreCase);
if (at._type == Set)
{
if (!wasLastSet || optionsLast != optionsAt || lastNodeCannotMerge || !RegexCharClass.IsMergeable(at._str))
{
wasLastSet = true;
lastNodeCannotMerge = !RegexCharClass.IsMergeable(at._str);
optionsLast = optionsAt;
break;
}
}
else if (!wasLastSet || optionsLast != optionsAt || lastNodeCannotMerge)
{
wasLastSet = true;
lastNodeCannotMerge = false;
optionsLast = optionsAt;
break;
}
// The last node was a Set or a One, we're a Set or One and our options are the same.
// Merge the two nodes.
j--;
prev = _children[j];
RegexCharClass prevCharClass;
if (prev._type == RegexNode.One)
{
prevCharClass = new RegexCharClass();
prevCharClass.AddChar(prev._ch);
}
else
{
prevCharClass = RegexCharClass.Parse(prev._str);
}
if (at._type == RegexNode.One)
{
prevCharClass.AddChar(at._ch);
}
else
{
RegexCharClass atCharClass = RegexCharClass.Parse(at._str);
prevCharClass.AddCharClass(atCharClass);
}
prev._type = RegexNode.Set;
prev._str = prevCharClass.ToStringClass();
}
else if (at._type == RegexNode.Nothing)
{
j--;
}
else
{
wasLastSet = false;
lastNodeCannotMerge = false;
}
break;
}
}
if (j < i)
{
_children.RemoveRange(j, i - j);
}
return(StripEnation(RegexNode.Nothing));
}
internal RegexNode ReduceAlternation()
{
if (this._children == null)
{
return(new RegexNode(0x16, this._options));
}
bool flag = false;
bool flag2 = false;
RegexOptions none = RegexOptions.None;
int num = 0;
int index = 0;
while (num < this._children.Count)
{
RegexCharClass class2;
RegexNode node = this._children[num];
if (index < num)
{
this._children[index] = node;
}
if (node._type == 0x18)
{
for (int i = 0; i < node._children.Count; i++)
{
node._children[i]._next = this;
}
this._children.InsertRange(num + 1, node._children);
index--;
goto Label_01C2;
}
if ((node._type != 11) && (node._type != 9))
{
goto Label_01AB;
}
RegexOptions options2 = node._options & (RegexOptions.RightToLeft | RegexOptions.IgnoreCase);
if (node._type == 11)
{
if ((flag && (none == options2)) && (!flag2 && RegexCharClass.IsMergeable(node._str)))
{
goto Label_011B;
}
flag = true;
flag2 = !RegexCharClass.IsMergeable(node._str);
none = options2;
goto Label_01C2;
}
if ((!flag || (none != options2)) || flag2)
{
flag = true;
flag2 = false;
none = options2;
goto Label_01C2;
}
Label_011B:
index--;
RegexNode node2 = this._children[index];
if (node2._type == 9)
{
class2 = new RegexCharClass();
class2.AddChar(node2._ch);
}
else
{
class2 = RegexCharClass.Parse(node2._str);
}
if (node._type == 9)
{
class2.AddChar(node._ch);
}
else
{
RegexCharClass cc = RegexCharClass.Parse(node._str);
class2.AddCharClass(cc);
}
node2._type = 11;
node2._str = class2.ToStringClass();
goto Label_01C2;
Label_01AB:
if (node._type == 0x16)
{
index--;
}
else
{
flag = false;
flag2 = false;
}
Label_01C2:
num++;
index++;
}
if (index < num)
{
this._children.RemoveRange(index, num - index);
}
return(this.StripEnation(0x16));
}