Question

示例代码：

Printf.ksprintf ignore "static string"

let dynamicString = Printf.StringFormat<unit>("dynamic string")
Printf.ksprintf ignore dynamicString // <- error

当我将静态字符串传递给 ksprintf 时，一切正常。但是如果我动态地形成一个字符串，则会出现编译错误：

类型'unit'与'string'类型不匹配

P.S。发现在FSharp.Core的来源：

/// <summary>Represents a statically-analyzed format when formatting 
/// arguments of the format operation and the last the overall return type.</summary>
type StringFormat<'T,'Result> = Format<'T, unit, string, 'Result>

/// <summary>Represents a statically-analyzed format when formatting builds a string. 
/// The type parameter indicates the arguments and return type of the 
/// format operation.</summary>
type StringFormat<'T> = StringFormat<'T,string>

Answer 1

格式字符串的正确类型不是unit。它应该是

let dynamicString = Printf.StringFormat<unit,unit>("dynamic string")

要找到它，请创建一个这样的函数：

let test arg = Printf.ksprintf ignore arg

并查看arg

的生成类型

使用动态字符串时ksprintf类型错误

1 个答案: