pipe<T, R> function

R Function(T) pipe<T, R>(List<R Function(dynamic)> fns)

Pipe (chain unary functions). Compose (f(g(x))). Once (run block only once). Roadmap #246-248.

Implementation

R Function(T) pipe<T, R>(List<R Function(dynamic)> fns) {
  return (T x) {
    dynamic v = x;
    for (final R Function(dynamic) f in fns) {
      v = f(v);
    }
    if (v is R) return v;
    throw StateError('pipe: result is ${v.runtimeType}, expected $R');
  };
}