Merge pull request #171 from moonbitlang/basic-types

add more description for basic types

README.md

@@ -260,7 +260,15 @@ fn init {
 
 ### Number
 
-MoonBit supports numeric literals, including decimal, binary, octal, and hexadecimal numbers.
+MoonBit have integer type and floating point type:
+
+|type|description|
+|-|-|
+|`Int`|32-bit signed integer|
+|`Int64`|64-bit signed integer|
+|`Double`|64-bit floating point, defined by IEEE754|
+
+MoonBit also supports numeric literals, including decimal, binary, octal, and hexadecimal numbers.
 
 To improve readability, you may place underscores in the middle of numeric literals such as `1_000_000`. Note that underscores can be placed anywhere within a number, not just every three digits.
 

zh-docs/README.md

@@ -268,7 +268,15 @@ fn init {
 
 ### 数字
 
-Moonbit 支持的数字字面量，包括十进制、二进制、八进制和十六进制。
+MoonBit 支持整型和浮点类型：
+
+|类型|描述|
+|-|-|
+|`Int`|32位有符号整数|
+|`Int64`|64位有符号整数|
+|`Double`|64位浮点数，由IEEE754定义|
+
+MoonBit 支持的数字字面量，包括十进制、二进制、八进制和十六进制。
 
 为了提升可读性，你可以在数字字面量内插入下划线，例如 `1_000_000`。
 注意，下划线可以插入到数字之间的任何位置，而非只能在每三个数字之间。