/// <summary>
/// Parses <paramref name="pattern"/>, calling appropriate overloads
/// in <paramref name="parser"/>
/// </summary>
/// <param name="pattern">Pattern to parse</param>
/// <param name="parser">Parser to call back</param>
public static void Parse(
WildcardPattern pattern, WildcardPatternParser parser)
{
parser.BeginWildcardPattern(pattern);
bool previousCharacterIsAnEscape = false;
bool previousCharacterStartedBracketExpression = false;
bool insideCharacterRange = false;
StringBuilder characterRangeContents = null;
StringBuilder characterRangeOperators = null;
foreach (char c in pattern.Pattern)
{
if (insideCharacterRange)
{
if (c == ']' && !previousCharacterStartedBracketExpression && !previousCharacterIsAnEscape)
{
// An unescaped closing square bracket closes the character set. In other
// words, there are no nested square bracket expressions
// This is different than the POSIX spec
// (at http://www.opengroup.org/onlinepubs/9699919799/functions/fnmatch.html),
// but we are keeping this behavior for back-compatibility.
insideCharacterRange = false;
parser.AppendBracketExpression(characterRangeContents.ToString(), characterRangeOperators.ToString(), pattern.Pattern);
characterRangeContents = null;
characterRangeOperators = null;
}
else if (c != pattern.EscapeCharacter || previousCharacterIsAnEscape)
{
characterRangeContents.Append(c);
characterRangeOperators.Append((c == '-') && !previousCharacterIsAnEscape ? '-' : ' ');
}
previousCharacterStartedBracketExpression = false;
}
else
{
if (c == '*' && !previousCharacterIsAnEscape)
{
parser.AppendAsterix();
}
else if (c == '?' && !previousCharacterIsAnEscape)
{
parser.AppendQuestionMark();
}
else if (c == '[' && !previousCharacterIsAnEscape)
{
insideCharacterRange = true;
characterRangeContents = new StringBuilder();
characterRangeOperators = new StringBuilder();
previousCharacterStartedBracketExpression = true;
}
else if (c != pattern.EscapeCharacter || previousCharacterIsAnEscape)
{
parser.AppendLiteralCharacter(c);
}
}
previousCharacterIsAnEscape = (c == pattern.EscapeCharacter) && (!previousCharacterIsAnEscape);
}
if (insideCharacterRange)
{
throw NewWildcardPatternException(pattern.Pattern);
}
if (previousCharacterIsAnEscape)
{
if (!pattern.Pattern.Equals($"{pattern.EscapeCharacter}", StringComparison.Ordinal)) // Win7 backcompatibility requires treating '`' pattern as '' pattern when this code was used with PowerShell.
{
parser.AppendLiteralCharacter(pattern.Pattern[pattern.Pattern.Length - 1]);
}
}
parser.EndWildcardPattern();
}
/// <summary>
/// Called from <see cref="Parse"/> method to indicate
/// the beginning of the wildcard pattern.
/// Default implementation simply returns.
/// </summary>
/// <param name="pattern">
/// <see cref="WildcardPattern"/> object that includes both
/// the text of the pattern (<see cref="WildcardPattern.Pattern"/>)
/// and the pattern options (<see cref="WildcardPattern.Options"/>)
/// </param>
protected virtual void BeginWildcardPattern(WildcardPattern pattern)
{
}