7、深入探索PHP函数式编程的高级技巧

深入探索PHP函数式编程的高级技巧

1. 函数式编程基础回顾

在函数式编程里，函数的结构化方式有多种，像递归和部分函数等技巧能让函数更具灵活性。例如下面这个封装 str_repeat 的函数：

# Our function to wrap str_repeat.
# Note it takes one parameter, the $count
function repeat_str($count) {
  # This function returns another (closure) function,
  # which binds $count, and accepts a single parameter
  # $string. Note that *this* returned closure is the
  # actual function that gets used in compose().
  return function ($string) use ($count) {
    return str_repeat($string, $count);
  };
};
# Now let's compose those two functions together.
$ten_chars = compose(
    repeat_str(10),
    'display'
  );
# and run our composed function
echo $ten_chars('*');

执行这段代码会输出 **********