# Test lambda patterns
let
  # Basic destructuring
  f1 = {
    a,
    b,
  }:
    a + b;

  # With default values
  f2 = {
    a,
    b ? 10,
  }:
    a + b;

  # With ellipsis (extra fields allowed)
  f3 = {a, ...}: a * 2;

  # Named pattern with ellipsis to allow extra fields
  f4 = arg @ {
    a,
    b,
    ...
  }:
    a + b + arg.c;

  # Simple lambda (not a pattern)
  f5 = x: x + 1;
in {
  # Test basic destructuring
  test1 = f1 {
    a = 3;
    b = 4;
  };

  # Test with defaults (provide both)
  test2a = f2 {
    a = 5;
    b = 6;
  };

  # Test with defaults (use default for b)
  test2b = f2 {a = 5;};

  # Test ellipsis (extra field ignored)
  test3 = f3 {
    a = 7;
    extra = 999;
  };

  # Test named pattern
  test4 = f4 {
    a = 1;
    b = 2;
    c = 3;
  };

  # Test simple lambda
  test5 = f5 10;
}