《Programming Abstractions In C》学习第 47 天，p111-p113，总结如下：
一、技术总结 1.boilerplate
/* * File: random.h * Version: 1.0 * Last modified on Fri Jul 22 16:44:36 1994 by eroberts * ----------------------------------------------------- * This interface provides several functions for generating * pseudo-random numbers. */
#ifndef _random_h#define _random_h
#include "genlib.h"#include <stdlib.h>
/* * Constant: RAND_MAX * ------------------ * Unfortunately, several libraries that supposedly conform to * the ANSI standard do not define RAND_MAX in <stdlib.h>. To * reduce portability problems, this interface defines RAND_MAX * to be the largest positive integer if it is undefined. */
#ifndef RAND_MAX# define RAND_MAX ((int) ((unsigned) ~0 >> 1))#endif
/* * Function: Randomize * Usage: Randomize(); * ------------------- * This function sets the random seed so that the random sequence * is unpredictable. During the debugging phase, it is best not * to call this function, so that program behavior is repeatable. */
void Randomize(void);
/* * Function: RandomInteger * Usage: n = RandomInteger(low, high); * ------------------------------------ * This function returns a random integer in the range low to high, * inclusive. */
int RandomInteger(int low, int high);
/* * Function: RandomReal * Usage: d = RandomReal(low, high); * --------------------------------- * This function returns a random real number in the half-open * interval [low .. high), meaning that the result is always * greater than or equal to low but strictly less than high. */
double RandomReal(double low, double high);
/* * Function: RandomChance * Usage: if (RandomChance(p)) . . . * --------------------------------- * The RandomChance function returns TRUE with the probability * indicated by p, which should be a floating-point number between * 0 (meaning never) and 1 (meaning always). For example, calling * RandomChance(.30) returns TRUE 30 percent of the time. */
bool RandomChance(double p);
#endif
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p113，These three lines are often referred to as interface boilerplate。boilerplate 这个词会在计算机相关的教材中会经常看到，英文的意思是：“text that can be copied and used in computer program，with only small changes.”(模板)，之所以叫模板，是因为在每个头文件中都有这三句。这个单词不难理解，关键是通过此次的教材对这个单词有一个具体的、形象的记录，当提到这个单词，就知道具体指的是什么。
二、英语总结
1.roll a die 一句里面的 die 是什么意思？答：die: n.a small cube with a different number of spots on each side.(骰子)，所以 roll a die 的就是"掷骰子"。
2.along with 语法
答：along with 在表示伴随、以及或连同等意思时，两者之间无先后顺序，可能在前也可能在后。这点与 follow 不同。示例：For each of these functions, the interface contains one-line prototype along with a comment that describe the purpose of the function from the perspective of clients.
3.up to 语法答：原文：The line:
cause the compiler to skip any text up to the #endif line if the the symbol _random_h has been previously defined。
up to 短语主要有两种用法：
(1)adv. used to say that sth is less than or equal to but not more than a stated value。
(2)adv. until。
都表示的是“程度”，而不是“方向”。
三、参考资料
1.编程
1)Eric S.Roberts，《Programming Abstractions in C》：https://book.douban.com/subject/2003414
2.英语
1)Etymology Dictionary：https://www.etymonline.com
2)Cambridage Dictionary：https://dictionary.cambridge.org
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