Dhall

Question

我正在使用 Dhall 1.39.0 并收到此错误：

Error: Expression doesn't match annotation

- Text
+ { … : … } (a record type)
[snip]

You or the interpreter annotated this expression:

[ file contents ] 

... with this type or kind:

↳ Text

... but the inferred type or kind of the expression is actually:

↳ { Sentences :
      List
        { Name : Text
        , Object : Text
        , Statement : Bool
        , Subject : Text
        , Verb : Text
        }
  , Version : Text
  }

这是从 cat show-and-tell.dhall | ~/external-programs/bin/dhall --explain text 产生的。

请注意，我可以将相关的 dhall 文件加载到 dhall-golang 库中，并使其正确呈现。所以我有点困惑。

这里有一个有点做作的示例文件：


let Sentence : Type  =
{
  Name : Text,
  Subject : Text ,
  Verb : Text ,
  Object : Text ,
  Statement : Bool
}
let Information : Type = {
  Version : Text,
  Sentences : List Sentence
}


let all = ".+"

let answer : Information =  {
    Version = "v1"
    , Sentences =
    [ { Name = "s1"
    , Subject = "bobross"
    , Verb = "${all}"
    , Object = "${all}"
    , Statement = True
    }
    , { Name = "s2"
    , Subject = "Everyone"
    , Verb = "${all}"
    , Object = "${all}"
    , Statement = False
    }
    , { Name = "s3"
    , Subject = "picasso"
    , Verb = "questions"
    , Object = "${all}"
    , Statement = True
    }
  ]
}
in answer

Answer 1

dhall text 用于呈现 Text 类型的 Dhall 表达式的值（有点像，例如 jq 的 -r 选项）：

$ echo '"Foo"' | dhall text
Foo

与

相比

$ echo '"Foo"' | dhall
"Foo"

您的表达式的类型为 Information；你只需要 dhall 本身。

$ cat show-and-tell.dhall | dhall
{ Sentences =
  [ { Name = "s1"
    , Object = ".+"
    , Statement = True
    , Subject = "bobross"
    , Verb = ".+"
    }
  , { Name = "s2"
    , Object = ".+"
    , Statement = False
    , Subject = "Everyone"
    , Verb = ".+"
    }
  , { Name = "s3"
    , Object = ".+"
    , Statement = True
    , Subject = "picasso"
    , Verb = "questions"
    }
  ]
, Version = "v1"
}

Dhall - 表达式与注释不匹配，应键入文本

Dhall - Expression doesn't match annotation, type Text expected