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130 lines
3.2 KiB
Markdown
130 lines
3.2 KiB
Markdown
# 功能
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[](https://gezf7g7pd5.execute-api.ap-northeast-1.amazonaws.com/default/source_up_to_date?owner=erg-lang&repos=erg&ref=main&path=doc/EN/API/funcs.md&commit_hash=06f8edc9e2c0cee34f6396fd7c64ec834ffb5352)
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## 基本功能
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### if|T, U|(cond: Bool, then: T, else: U) -> T or U
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### map|T, U|(i: Iterable T, f: T -> U) -> Map U
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请注意，参数的顺序与 Python 相反
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### log(x: Object, type: LogType = Info) -> None
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在调试显示中记录"x"。执行完成后汇总并显示日志
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支持表情符号的终端根据"类型"添加前缀
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* type == Info: 💬
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* type == Ok: ✅
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* type == Warn: ⚠️
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* type == Hint: 💡
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### panic(msg: Str) -> Panic
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显示msg并停止
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支持表情符号的终端有一个🚨前缀
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### discard|T|(x: ...T) -> NoneType
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扔掉`x`。不使用返回值时使用。与 `del` 不同，它不会使变量 `x` 不可访问
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```python
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p! x =
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# q!应该返回一些不是None或()的值
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# 如果不需要，请使用`discard`
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discard q!(x)
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f x
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discard True
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assert True # OK
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```
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### import(path: Path) -> Module or CompilerPanic
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导入一个模块。如果找不到模块，则引发编译错误
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### eval(code: Str) -> Object
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将`code`作为代码进行评估并返回
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### classof(object: Object) -> Class
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返回`object`的类
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但是，由于无法比较类，如果要判断实例，请使用`object in Class`而不是`classof(object) == Class`
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编译时确定的结构类型是通过`Typeof`获得的
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## Iterator, Array生成系统
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### repeat|T|(x: T) -> RepeatIterator T
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```python
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rep = repeat 1 # Repeater(1)
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for! rep, i =>
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print! i
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# 1 1 1 1 1 ...
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```
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### dup|T, N|(x: T, N: Nat) -> [T; N]
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```python
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[a, b, c] = dup new(), 3
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print! a # <Object object>
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print! a == b # False
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```
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### cycle|T|(it: Iterable T) -> CycleIterator T
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```python
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cycle([0, 1]).take 4 # [0, 1, 0, 1]
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cycle("hello").take 3 # "hellohellohello"
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```
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## 定数式関数
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### Class
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生成新类。 与`Inherit`不同，通过`Class`与基类型（第一个参数`Base`）无关，并且方法丢失。
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```python
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C = Class {i = Int}
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NewInt = Class Int
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Months = Class 1..12
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jan = Months.new(1)
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jan + Months.new(2) # TypeError: `+` is not implemented for 'Months'
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match jan:
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1 -> log "January"
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_ -> log "Other"
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```
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### Inherit
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继承类可以直接使用父类(`Super`)的方法。可以在第二参数`Layout`中指定新的布局。
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此时，必须`Super.Base:> Layout`
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```python
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@Inheritable
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C = Class {i = Int}
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D = Inherit C, {i = Int; j = Int} # C.Layout == {i = Int} :> {i = Int; j = Int}
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E! = Inherit C, {i = Int!} # {i = Int} :> {i = Int!}
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```
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### Trait
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创造一个新的trait。目前，只能指定记录类型
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### Typeof
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返回参数类型。如果要获取运行时类，请使用`classof`
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如果您将其用于类型规范，则会出现警告
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```python,compile_warn
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x: Typeof i = ...
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# TypeWarning: Typeof(i) == Int, please replace it
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```
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### Deprecated
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作为解码器使用。警告不推荐使用的类型或函数
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