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「Program=Proof筆記」修訂間的差異
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→1.3遞迴型別
Tankianting（討論 | 貢獻） （→1.1介紹） |
Tankianting（討論 | 貢獻） |
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<pre>let f = function ... 即 let f x = match x with ...</pre> | <pre>let f = function ... 即 let f x = match x with ...</pre> | ||
====Bool==== | |||
<pre>type bool = True | False</pre> | |||
====List==== | |||
<pre>type 'a list = | |||
| Nil | |||
| Cons of 'a * 'a list</pre> | |||
====coproducts==== | |||
<pre>type ('a, 'b) either = | |||
| Left of 'a | |||
| Right of 'b</pre> | |||
====unit==== | |||
<pre>type unit = | T</pre> | |||
只有這個值 <code>()</code> | |||
====Empty==== | |||
<pre>type Empty = |</pre> | |||
====Natural Number==== | |||
<pre>type Nat = | |||
|Zero | |||
|Suc of nat</pre> | |||
====例外處理：Option type and exception==== | |||
處理例外的方式 | |||
Option type | |||
<pre>type 'a option = | |||
| Some of 'a | |||
| None | |||
</pre> | |||
exception | |||
<pre>let hd l = | |||
match l with | |||
| x::l -> x | |||
| [] -> raise Not_found</pre> | |||
搭配 | |||
<pre>try | |||
... | |||
with | |||
| Not_found -> ...</pre> | |||
[[分類:資訊]] | [[分類:資訊]] | ||
[[分類:邏輯學]] | [[分類:邏輯學]] | ||