可读代码的艺术

send: deliver, dispatch, announce, distribute, route
find: search, extract, locate, recover
start: launch, create, begin, open
make: create, set up, build, generate, compose, add, new

delay → delay_secs
password → plaintext_password

// 外形不同
public class PerformanceTester {
 public static final TcpConnectionSimulator wifi = new TcpConnectionSimulator(
 500, /* Kbps */
 80, /* millisecs latency */
 200, /* jitter */
 1 /* packet loss % */);
 public static final TcpConnectionSimulator t3_fiber =
 new TcpConnectionSimulator(
 45000, /* Kbps */
 10, /* millisecs latency */
 0, /* jitter */
 0 /* packet loss % */);
 public static final TcpConnectionSimulator cell = new TcpConnectionSimulator(
 100, /* Kbps */
 400, /* millisecs latency */
 250, /* jitter */
 5 /* packet loss % */);
}

// 外形相同
public class PerformanceTester {
 public static final TcpConnectionSimulator wifi =
 new TcpConnectionSimulator(
 500, /* Kbps */
 80, /* millisecs latency */
 200, /* jitter */
 1 /* packet loss % */);
 public static final TcpConnectionSimulator t3_fiber =
 new TcpConnectionSimulator(
 45000, /* Kbps */
 10, /* millisecs latency */
 0, /* jitter */
 0 /* packet loss % */);
 public static final TcpConnectionSimulator cell =
 new TcpConnectionSimulator(
 100, /* Kbps */
 400, /* millisecs latency */
 250, /* jitter */
 5 /* packet loss % */);
}

// 另一种注释方法
public class PerformanceTester {
 // TcpConnectionSimulator(throughput, latency, jitter, packet_loss)
 // [Kbps] [ms] [ms] [percent]
 public static final TcpConnectionSimulator wifi =
 new TcpConnectionSimulator(500, 80, 200, 1);
 public static final TcpConnectionSimulator t3_fiber =
 new TcpConnectionSimulator(45000, 10, 0, 0);
 public static final TcpConnectionSimulator cell =
 new TcpConnectionSimulator(100, 400, 250, 5);
}

# remove everything after the second '*'
name = '*'.join(line.split('*')[:2])

// Find the Node in the given subtree, with the given name, using the given depth.
Node* FindNodeInSubtree(Node* subtree, string name, int depth);

// Find a Node with the given 'name' or return NULL.
// If depth <= 0, only 'subtree' is inspected.
// If depth == N, only 'subtree' and N levels below are inspected.
Node* FindNodeInSubtree(Node* subtree, string name, int depth);

// Surprisingly, a binary tree was 40% faster than a hash table for this data.
// The cost of computing a hash was more than the left/right comparisons.

// TODO(dustin): handle other image formats besides JPEG

TODO: Stuff I haven’t gotten around to yet
FIXME: Known-broken code here
HACK: Admittedly inelegant solution to a problem
XXX: Danger! major problem here

// Impose a reasonable limit - no human can read that much anyway.
const int MAX_RSS_SUBSCRIPTIONS = 1000;

// This class contains a number of members that store the same information as in the
// database, but are stored here for speed. When this class is read from later, those
// members are checked first to see if they exist, and if so are returned; otherwise the
// database is read from and that data stored in those fields for next time.

// 其实就是 ↓

// This class acts as a caching layer to the database.

while (bytes_received < bytes_expected)

exponent >= 0 ? mantissa * (1 << exponent) : mantissa / (1 << -exponent)

public boolean Contains(String str, String substr) {
 if (str == null || substr == null) return false;
 if (substr.equals("")) return true;
 // ...
}

if (user_result == SUCCESS) {
  if (permission_result != SUCCESS) {
    reply.WriteErrors('error reading permissions')
    reply.Done()
    return
  }
  reply.WriteErrors('')
} else {
  reply.WriteErrors(user_result)
}
reply.Done()

if (user_result != SUCCESS) {
  reply.WriteErrors(user_result)
  reply.Done()
  return
}
if (permission_result != SUCCESS) {
  reply.WriteErrors(permission_result)
  reply.Done()
  return
}
reply.WriteErrors('')
reply.Done()

var remove_one = function(array, value_to_remove) {
  var index_to_remove = null
  for (var i = 0; i < array.length; i += 1) {
    if (array[i] === value_to_remove) {
      index_to_remove = i
      break
    }
  }
  if (index_to_remove !== null) {
    array.splice(index_to_remove, 1)
  }
}

class LargeClass {
 string str_;
 void Method1() {
 str_ = ...;
 Method2();
 }
 void Method2() {
 // Uses str_
 }
 // Lots of other methods that don't use str_ ...
};

class LargeClass {
 void Method1() {
 string str = ...;
 Method2(str);
 }
 void Method2(string str) {
 // Uses str
 }
 // Now other methods can't see str.
};

var vote_changed = function(old_vote, new_vote) {
  var score = get_score()
  if (new_vote !== old_vote) {
    if (new_vote === 'Up') {
      score += old_vote === 'Down' ? 2 : 1
    } else if (new_vote === 'Down') {
      score -= old_vote === 'Up' ? 2 : 1
    } else if (new_vote === '') {
      score += old_vote === 'Up' ? -1 : 1
    }
  }
  set_score(score)
}

var vote_value = function(vote) {
  if (vote === 'Up') {
    return +1
  }
  if (vote === 'Down') {
    return -1
  }
  return 0
}
var vote_changed = function(old_vote, new_vote) {
  var score = get_score()
  score -= vote_value(old_vote) // remove the old vote
  score += vote_value(new_vote) // add the new vote
  set_score(score)
}

$is_admin = is_admin_request();
if ($document) {
 if (!$is_admin && ($document['username'] != $_SESSION['username'])) {
 return not_authorized();
 }
} else {
 if (!$is_admin) {
 return not_authorized();
 }
}

if (is_admin_request()) {
 // authorized
} elseif ($document && ($document['username'] == $_SESSION['username'])) {
 // authorized
} else {
 return not_authorized();
}
// continue rendering the page ...