计算表达凹痕混乱

Question

我显然不了解计算表达中的缩进（我通常是地图/绑定的人）。

此代码编译

        seq {
            for concept in model.EsWondomainmodelconcepts do
                let attLookup = seq {
                    for att in concept.Attributes.EsWondomainmodelattributes do
                        for tag in (att.XmlTag |> Option.toArray) do
                            for mult in (att.Multiplicity.EspEnumeration.Identificationdisplaystring.String |> Option.toArray) do
                                (tag,multiplicityToRelationshipCardinality mult)
                } 
                (concept.XmlTag, attLookup |> Map.ofSeq)
        }
        |> Map.ofSeq
        |> WOnSchemaRawData

这并不是

        seq {
            for concept in model.EsWondomainmodelconcepts do
                let attLookup = seq { // FS3118 on this line
                    for att in concept.Attributes.EsWondomainmodelattributes do
                        for tag in (att.XmlTag |> Option.toArray) do
                            for mult in (att.Multiplicity.EspEnumeration.Identificationdisplaystring.String |> Option.toArray) do
                                (tag,multiplicityToRelationshipCardinality mult)
                } |> Map.ofSeq // FS0588 here
                (concept.XmlTag, attLookup)
        }
        |> Map.ofSeq
        |> WOnSchemaRawData

“让attlookup = ....” comply

Severity    Code    Description Project File    Line    Suppression State
Error   FS3118  Incomplete value or function definition. If this is in an expression, the body of the expression must be indented to the same column as the 'let' keyword.  

和1st“ |＆gt; map.ofseq”行clock offe

Severity    Code    Description Project File    Line    Suppression State
Error   FS0588  The block following this 'let' is unfinished. Every code block is an expression and must have a result. 'let' cannot be the final code element in a block. Consider giving this block an explicit result    

Answer 1

我相信我理解这一点而无需与编译器尝试。我将说明一些简单的代码段所发生的事情。

允许这样做：

let x = seq { 1; 2;
    3 }

但是这是不允许的，这对我来说很有意义，为什么不允许：

let x = seq { 1; 2;
    3 }
    |> Seq.sum

这对我也很有意义：

let x =
    seq { 1; 2;
        3 }
    |> Seq.sum

所以我怀疑您可以像最后一段一样格式化代码，这将是好的。