使用F#进行算术操作
基本类型:
类型 | 描述 | 示例 | .NET 类型 |
bool | True/false values | true,false | System.Boolean |
byte | 8-bit unsigned integers | 0uy,19uy,0xFFuy | System.Byte |
sbyte | 8-bit signed integers | 0y, 19y,0xFFy | System.SByte |
int16 | 16-bit signed integers | 0s, 19s,0x0800s | System.Int16 |
uint16 | 16-bit unsigned integers | 0us,19us,0x0800us | System.UInt16 |
int, int32 | 32-bit signed integers | 0, 19,0x0800,0b0001 | System.Int32 |
uint32 | 32-bit unsigned integers | 0u, 19u,0x0800u | System.UInt32 |
int64 | 64-bit signed integers | 0L, 19L,0x0800L | System.Int64 |
uint64 | 64-bit unsigned integers | 0UL,19UL,0x0800UL | System.UInt64 |
nativeint | Machine-sized signed integers | 0n, 19n,0x0800n | System.IntPtr |
unativeint | Machine-sized unsigned integers | 0un,19un,0x0800un | System.UIntPtr |
single,float32 | 32-bit IEEE floating-point | 0.0f,19.7f,1.3e4f | System.Single |
double,float | 64-bit IEEE floating-point | 0.0,19.7,1.3e4 | System.Double |
decimal | High-precision decimal values | 0M, 19M,19.03M | System.Decimal |
bigint | Arbitrarily large integers | 0I, 19I | Math.BigInt |
bignum | Arbitrary-precision rationals | 0N, 19N | Math.BigNum |
unit | The type with only one value | () | Core.Unit |
在F#中,对数字的加减乘除操作均是不检查的(unchecked);就是说如果超出范围,不会得到异常。例如,2147483647是最大的32位整数:
> 2147483647+1;;
val it : int = -2147483648
同时,我们也提供了检查溢出的实现:Microsoft.FSharp.Core.Operators.Checked。这个模块(module)中实现的操作将在移除发生时抛出System.OverflowException异常。
如果希望避免溢出,可以使用decimal,bigint和bignum类型。
除零将会得到System.DivideByZeroException,但浮点数(floating-point number)除外,浮点数除零将会返回Infinity和-Infinity。
通过类型推导(type inference)来确定操作符重载—如果没有重载则F#约定使用32位整数的操作符。
如果希望使用指定类型的操作符,则必须使用类型注释(type annotation)来帮助类型推导器推导出正确的结果:
> let squareAndAdd a b = a * a + b;;
val squareAndAdd : int -> int -> int
时间: 2024-08-07 03:26:47