isBlockedName function

bool isBlockedName(String first, String second)

Whether the two-word name first second is blocked: a blocked word, a blocked bigram, a blocked substring created by the join, or blocked initials.

Implementation

bool isBlockedName(String first, String second) {
  final a = first.toLowerCase();
  final b = second.toLowerCase();
  if (blockedWords.contains(a) || blockedWords.contains(b)) return true;
  if (a == b) return true;
  for (final (x, y) in blockedBigrams) {
    bool match(String p, String q) =>
        (x.isEmpty || p == x) && (y.isEmpty || q == y);
    if (match(a, b) || match(b, a)) return true;
  }
  for (final (p, q) in [(a, b), (b, a)]) {
    final joined = '$p$q';
    final boundary = p.length;
    for (final bad in blockedJoinSubstrings) {
      // Created by the join iff an occurrence spans the boundary.
      final from = boundary - bad.length + 1;
      final start = from < 0 ? 0 : from;
      final i = joined.indexOf(bad, start);
      if (i >= 0 && i < boundary) return true;
    }
  }
  final initials = '${first[0]}${second[0]}'.toUpperCase();
  return blockedInitials.contains(initials);
}