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| diff --git a/zh-cn/nim-cn.html.markdown b/zh-cn/nim-cn.html.markdown new file mode 100644 index 00000000..dc662b1e --- /dev/null +++ b/zh-cn/nim-cn.html.markdown @@ -0,0 +1,283 @@ +--- +language: Nim +filename: learnNim-cn.nim +contributors: +    - ["Jason J. Ayala P.", "http://JasonAyala.com"] +    - ["Dennis Felsing", "http://felsin9.de/nnis/"] +translators: +    - ["lzw-723", "https://github.com/lzw-723"] +lang: zh-cn +--- + +Nim(原名Nimrod)是一种静态类型的命令式编程语言, +它能在不影响运行时效率的情况下为程序员提供强大的功能。 + +Nim语言高效、有表现力、优雅。 + +```nim +# 单行注释以一个#开头 + +#[ +  这是多行注释 +  在Nim语言中,多行注释可以嵌套,以#[开头,以]#结尾 +]# + +discard """ +这也可以作为多行注释使用。 +或者用于无法解析、损坏的代码 +""" + +var                     # 声明(和赋值)变量 +  letter: char = 'n'    # 带或不带类型批注 +  lang = "N" & "im" +  nLength: int = len(lang) +  boat: float +  truth: bool = false + + let            # 使用let*一次性*声明和绑定变量。 +  legs = 400   # legs是不可改变的。 +  arms = 2_000 # _会被忽略,对long类型非常有用。 +  aboutPi = 3.15 + +const            # 常量在编译时计算。这确保了 +  debug = true   # 性能,在编译时表达式中很有用。 +  compileBadCode = false + +when compileBadCode:            # `when`是编译时的`if` +  legs = legs + 1               # 这个错误永远不会被编译。 +  const input = readline(stdin) # const在编译时必须是已知的。 + +discard 1 > 2 # 注意:如果表达式的结果未使用, +              # 编译器会发出警告。`discard`绕过了这一点。 + + +# +# 数据结构 +# + +# 元组(Tuple) + +var +  child: tuple[name: string, age: int]   # 元组有*字段名* +  today: tuple[sun: string, temp: float] # 和*顺序* + + +child = (name: "Rudiger", age: 2) # 使用字面值()一次性赋值全部 +today.sun = "Overcast"            # 也可以单独赋值 +today.temp = 70.1 + +# 序列(Sequence) + +var +  drinks: seq[string] + +drinks = @["Water", "Juice", "Chocolate"] # @[V1,..,Vn] 是序列的字面值 + +drinks.add("Milk") + +if "Milk" in drinks: +  echo "We have Milk and ", drinks.len - 1, " other drinks" + +let myDrink = drinks[2] + +# +# 自定义类型 +# + +# 定义你自己的类型使得编译器为你工作。 +# 这使得静态类型变得强大和有用。 + +type +  Name = string # 类型别名为你提供一个新类型, +  Age = int     # 该类型可与旧类型互换,但更具描述性。 +  Person = tuple[name: Name, age: Age] # 也可以定义数据结构。 +  AnotherSyntax = tuple +    fieldOne: string +    secondField: int + +var +  john: Person = (name: "John B.", age: 17) +  newage: int = 18 # 在这里使用Age比int要好 + +john.age = newage # 仍然有效,因为int和Age同义 + +type +  Cash = distinct int    # `distinct`使一个新类型与它的基本类型不兼容。 +  Desc = distinct string + +var +  money: Cash = 100.Cash # `.Cash`把int转换成我们的类型 +  description: Desc  = "Interesting".Desc + +when compileBadCode: +  john.age  = money        # 错误!age是int类型、money是Cash类型 +  john.name = description  # 编译器说:“没门!” + +# +# 更多类型和数据结构 +# + +# 枚举类型只能具有有限数量的值之一 + +type +  Color = enum cRed, cBlue, cGreen +  Direction = enum # 可选格式 +    dNorth +    dWest +    dEast +    dSouth +var +  orient = dNorth # `orient`的类型是Direction,值是`dNorth` +  pixel = cGreen # `pixel`的类型是Color,值是`cGreen` + +discard dNorth > dEast # Enum通常是“序数”类型 + +# 子范围指定有限的有效范围 + +type +  DieFaces = range[1..20] # 只有从1到20的int才是有效值 +var +  my_roll: DieFaces = 13 + +when compileBadCode: +  my_roll = 23 # 错误! + +# 数组(Array) + +type +  RollCounter = array[DieFaces, int]  # 数组长度固定 +  DirNames = array[Direction, string] # 以任意有序类型索引 +  Truths = array[42..44, bool] +var +  counter: RollCounter +  directions: DirNames +  possible: Truths + +possible = [false, false, false] # 数组字面以[V1,..,Vn]表示 +possible[42] = true + +directions[dNorth] = "Ahh. The Great White North!" +directions[dWest] = "No, don't go there." + +my_roll = 13 +counter[my_roll] += 1 +counter[my_roll] += 1 + +var anotherArray = ["Default index", "starts at", "0"] + +# 可用的数据结构包括表、集合、列表、队列、压缩前缀树。 +# http://nim-lang.org/docs/lib.html#collections-and-algorithms + +# +# IO和控制流 +# + +# `case`, `readLine()` + +echo "Read any good books lately?" +case readLine(stdin) +of "no", "No": +  echo "Go to your local library." +of "yes", "Yes": +  echo "Carry on, then." +else: +  echo "That's great; I assume." + +# `while`, `if`, `continue`, `break` + +import strutils as str # http://nim-lang.org/docs/strutils.html +echo "I'm thinking of a number between 41 and 43. Guess which!" +let number: int = 42 +var +  raw_guess: string +  guess: int +while guess != number: +  raw_guess = readLine(stdin) +  if raw_guess == "": continue # 跳出循环 +  guess = str.parseInt(raw_guess) +  if guess == 1001: +    echo("AAAAAAGGG!") +    break +  elif guess > number: +    echo("Nope. Too high.") +  elif guess < number: +    echo(guess, " is too low") +  else: +    echo("Yeeeeeehaw!") + +# +# 循环(Iteration) +# + +for i, elem in ["Yes", "No", "Maybe so"]: # 也可以是`for elem in` +  echo(elem, " is at index: ", i) + +for k, v in items(@[(person: "You", power: 100), (person: "Me", power: 9000)]): +  echo v + +let myString = """ +an <example> +`string` to +play with +""" # 多行字符串 + +for line in splitLines(myString): +  echo(line) + +for i, c in myString:       # 索引和字符。或使用'for j in'只有字符 +  if i mod 2 == 0: continue # 紧凑的'if'形式 +  elif c == 'X': break +  else: echo(c) + +# +# 过程(Procedure) +# + +type Answer = enum aYes, aNo + +proc ask(question: string): Answer = +  echo(question, " (y/n)") +  while true: +    case readLine(stdin) +    of "y", "Y", "yes", "Yes": +      return Answer.aYes  # 枚举类型可以 +    of "n", "N", "no", "No": +      return Answer.aNo +    else: echo("Please be clear: yes or no") + +proc addSugar(amount: int = 2) = # amount默认是2,不返回任何值 +  assert(amount > 0 and amount < 9000, "Crazy Sugar") +  for a in 1..amount: +    echo(a, " sugar...") + +case ask("Would you like sugar in your tea?") +of aYes: +  addSugar(3) +of aNo: +  echo "Oh do take a little!" +  addSugar() +# 这里不需要使用`else` 。只能是`yes`和`no`。 + +# +# 外部函数接口(FFI) +# + +# 因为Nim可以编译为C,使用外部函数接口(FFI)很简单: + +proc strcmp(a, b: cstring): cint {.importc: "strcmp", nodecl.} + +let cmp = strcmp("C?", "Easy!") +``` + +除此以外,Nim通过元编程、性能和编译时特性将自己与其他同类分离开来。 + +## 进阶阅读 + +* [主页](http://nim-lang.org) +* [下载](http://nim-lang.org/download.html) +* [社区](http://nim-lang.org/community.html) +* [常见问题](http://nim-lang.org/question.html) +* [文档](http://nim-lang.org/documentation.html) +* [参考手册](http://nim-lang.org/docs/manual.html) +* [标准库](http://nim-lang.org/docs/lib.html) +* [Rosetta Code](http://rosettacode.org/wiki/Category:Nim) | 
