private void _parse() {
if (PathString.IsEmpty()) {
BplRuntimeException.Throw("Path string is empty");
}
var parts = PathString.Split(@"\.");
_segments = new PathSegment[parts.Length];
for (int i = 0, j = 0; i < parts.Length; i++) {
try {
var part = parts[i];
var name = part;
var k1 = part.IndexOf("[");
var k2 = part.IndexOf("]");
if (k1 < 0 && k2 < 0) {
_segments[i] = new SingleItemSegment(name);
} else {
if (k1 <= 0 || k1 >= k2) {
j += k1; throw new Exception();
}
if (k2 != part.Length - 1) {
j += k2; throw new Exception();
}
name = part.Before(k1);
if (k1 == k2 - 1) {
if (i == parts.Length - 1) {
j += k1; throw new Exception("A cursor expression [] cannot appear at the end of the property path.");
}
_segments[i] = new CurrentItemSegment(name);
} else {
var qualifier = part.Between(k1 + 1, k2 - 1);
if (qualifier == "*") {
if (i < parts.Length - 1) {
j += k1; throw new Exception("A collection expression [*] can only appear at the end of the property path.");
}
_segments[i] = new CollectionSegment(name);
} else {
int index;
if (Int32.TryParse(qualifier, out index) && index >= 0) {
_segments[i] = new IndexedItemSegment(name, index);
} else {
j += k1; throw new Exception("Invalid index [{0}].".Substitute(qualifier));
}
}
}
}
if (!BplLanguage.IsLazyLoading && !BplLanguage.PropertyNames.Contains(name)) {
throw new Exception("'{0}' is an invalid or unknown property name.".Substitute(name));
}
j += part.Length;
} catch (Exception e) {
BplRuntimeException.Throw("Error in path string '{0}', near position {1}.".Substitute(PathString, j), e);
}
}
}
public ValueTask <int> GetTotalCount(
[Parent] CollectionSegment segment,
CancellationToken cancellationToken) =>
segment.GetTotalCountAsync(cancellationToken);
