note for "The Art of Readable Code" - CH13 Writing Less Code

The most readable code is no code at all.

Programmer最重要的技能之一就是知道哪些code不用寫，因為寫出來就要測試&維護，越小的程式碼越容易被維護，coupling程度越低越好，最好彼此獨立，有幾個方向:

1. Create as much generic “utility” code as possible to remove duplicated code. (See Chapter 10, Extracting Unrelated Subproblems.)
2. Remove unused code or useless features. (See the following sidebar.)
3. Keep your project compartmentalized into disconnected subprojects.
4. Generally, be conscious of the “weight” of your codebase. Keep it light and nimble.

Be Familiar with the Libraries Around You

每隔一段時間應該要花一下時間，讀一下你的 standard library，目的在於能對standard library的API有概念，以便在coding時能聯想到,並大量且反覆地使用這些library。

參考資料:
• The Art of Readable Code

note for "The Art of Readable Code" - CH12 Turning Thoughts into Code

You do not really understand something unless you can explain it to your grandmother. 
  — Albert Einstein  

先用口語描述演算法後，再轉成程式碼，能讓programmer寫出更自然的code，也有助於找出可以分解的子問題。

 We are reading three row iterators in parallel.
 Whenever the rows' times don't line up, advance the rows so they do line up.
 Then print the aligned rows, and advance the rows again.
 Keep doing this until there are no more matching rows left.

上述口語轉成的code為

def PrintStockTransactions(): 
    stock_iter = ...
    price_iter = ... 
    num_shares_iter = ...

    while True:
        time = AdvanceToMatchingTime(stock_iter, price_iter, num_shares_iter) 
        if time is None:
            return
        # Print the aligned rows.
        print "@", time,
        print stock_iter.ticker_symbol,
        print price_iter.price,
        print num_shares_iter.number_of_shares
        stock_iter.NextRow()
        price_iter.NextRow()
        num_shares_iter.NextRow()

參考資料:
• The Art of Readable Code

note for "The Art of Readable Code" - CH11 One Task at a Time

Code should be organized so that it’s doing only one task at a time.舉個投票例子，投UP則+1，Down則-1，結果為所有投票總和，如果依據該rule，則code應該是

var vote_changed = function (vote) {
    var score = get_score();
    score += vote_value(vote);
    set_score(score);
};

基本上這個章節的概念跟前一章節差不多"將子問題抽離，讓function專注在處理問題本身上面"。其餘細節就不贅述了。

參考資料:
• The Art of Readable Code