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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) |