where method

void where(
  1. String param,
  2. String regex
)

only match param when its text matches regex, see Route.where. A leading ^ and a trailing $ are dropped: the regex must match the whole param text anyway, and inside the route regex they would never match.

Implementation

void where(String param, String regex) {
  (wheres ??= <String, String>{})[param] = _withoutAnchors(regex);
  _compiledFor = null;
  _whereChecks = null;
}