private readonly int[] _rules; // negative -> group #, positive -> string #
/// <summary>
/// Since RegexReplacement shares the same parser as Regex,
/// the constructor takes a RegexNode which is a concatenation
/// of constant strings and backreferences.
/// </summary>
public RegexReplacement(string rep, RegexNode concat, Hashtable _caps)
{
if (concat.Type != RegexNode.Concatenate)
{
throw ThrowHelper.CreateArgumentException(ExceptionResource.ReplacementError);
}
Span <char> vsbStack = stackalloc char[256];
var vsb = new ValueStringBuilder(vsbStack);
FourStackStrings stackStrings = default;
var strings = new ValueListBuilder <string>(MemoryMarshal.CreateSpan(ref stackStrings.Item1 !, 4));
var rules = new ValueListBuilder <int>(stackalloc int[64]);
int childCount = concat.ChildCount();
for (int i = 0; i < childCount; i++)
{
RegexNode child = concat.Child(i);
switch (child.Type)
{
case RegexNode.Multi:
vsb.Append(child.Str !);
break;
case RegexNode.One:
vsb.Append(child.Ch);
break;
case RegexNode.Ref:
if (vsb.Length > 0)
{
rules.Append(strings.Length);
strings.Append(vsb.ToString());
vsb = new ValueStringBuilder(vsbStack);
}
int slot = child.M;
if (_caps != null && slot >= 0)
{
slot = (int)_caps[slot] !;
}
rules.Append(-Specials - 1 - slot);
break;
default:
throw ThrowHelper.CreateArgumentException(ExceptionResource.ReplacementError);
}
}
if (vsb.Length > 0)
{
rules.Append(strings.Length);
strings.Append(vsb.ToString());
}
Pattern = rep;
_strings = strings.AsSpan().ToArray();
_rules = rules.AsSpan().ToArray();
rules.Dispose();
}
private bool _hasBackreferences; // true if the replacement has any backreferences; otherwise, false
/// <summary>
/// Since RegexReplacement shares the same parser as Regex,
/// the constructor takes a RegexNode which is a concatenation
/// of constant strings and backreferences.
/// </summary>
public RegexReplacement(string rep, RegexNode concat, Hashtable _caps)
{
Debug.Assert(concat.Kind == RegexNodeKind.Concatenate, $"Expected Concatenate, got {concat.Kind}");
var vsb = new ValueStringBuilder(stackalloc char[256]);
FourStackStrings stackStrings = default;
var strings = new ValueListBuilder <string>(MemoryMarshal.CreateSpan(ref stackStrings.Item1 !, 4));
var rules = new ValueListBuilder <int>(stackalloc int[64]);
int childCount = concat.ChildCount();
for (int i = 0; i < childCount; i++)
{
RegexNode child = concat.Child(i);
switch (child.Kind)
{
case RegexNodeKind.Multi:
vsb.Append(child.Str !);
break;
case RegexNodeKind.One:
vsb.Append(child.Ch);
break;
case RegexNodeKind.Backreference:
if (vsb.Length > 0)
{
rules.Append(strings.Length);
strings.Append(vsb.AsSpan().ToString());
vsb.Length = 0;
}
int slot = child.M;
if (_caps != null && slot >= 0)
{
slot = (int)_caps[slot] !;
}
rules.Append(-Specials - 1 - slot);
_hasBackreferences = true;
break;
default:
Debug.Fail($"Unexpected child kind {child.Kind}");
break;
}
}
if (vsb.Length > 0)
{
rules.Append(strings.Length);
strings.Append(vsb.ToString());
}
vsb.Dispose();
Pattern = rep;
_strings = strings.AsSpan().ToArray();
_rules = rules.AsSpan().ToArray();
rules.Dispose();
}
