gistfile1.txt

Prelude> :load microlens-ex.hs 
[1 of 1] Compiling Main             ( microlens-ex.hs, interpreted )

microlens-ex.hs:17:5: error:
    • No instance for (Data.String.IsString (Maybe Text))
        arising from the literal ‘"true"’
    • In the first argument of ‘(&)’, namely ‘"true"’
      In the expression: "true" & _Bool .~ False
      In an equation for ‘b’: b = "true" & _Bool .~ False
   |
17 | b = "true" & _Bool .~ False  -- "false"
   |     ^^^^^^

microlens-ex.hs:17:14: error:
    • No instance for (AsPrimitive (Maybe Text))
        arising from a use of ‘_Bool’
    • In the first argument of ‘(.~)’, namely ‘_Bool’
      In the second argument of ‘(&)’, namely ‘_Bool .~ False’
      In the expression: "true" & _Bool .~ False
   |
17 | b = "true" & _Bool .~ False  -- "false"
   |              ^^^^^

microlens-ex.hs:24:5: error:
    • Ambiguous type variable ‘s2’ arising from the literal ‘"[1, 2, 3]"’
      prevents the constraint ‘(Data.String.IsString
                                  s2)’ from being solved.
      Probable fix: use a type annotation to specify what ‘s2’ should be.
      These potential instances exist:
        instance Data.String.IsString Value
          -- Defined in ‘aeson-1.2.4.0:Data.Aeson.Types.Internal’
        instance Data.String.IsString Text -- Defined in ‘Data.Text’
        instance a ~ Char => Data.String.IsString [a]
          -- Defined in ‘Data.String’
        ...plus 8 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the first argument of ‘(^..)’, namely ‘"[1, 2, 3]"’
      In the expression: "[1, 2, 3]" ^.. values
      In an equation for ‘c’: c = "[1, 2, 3]" ^.. values
   |
24 | c = "[1, 2, 3]" ^.. values  -- [Number 1.0, Number 2.0, Number 3.0]
   |     ^^^^^^^^^^^

microlens-ex.hs:24:21: error:
    • Ambiguous type variable ‘s2’ arising from a use of ‘values’
      prevents the constraint ‘(AsValue s2)’ from being solved.
      Probable fix: use a type annotation to specify what ‘s2’ should be.
      These potential instances exist:
        instance AsValue Value -- Defined in ‘Lens.Micro.Aeson’
        instance AsValue Text -- Defined in ‘Lens.Micro.Aeson’
        instance AsValue String -- Defined in ‘Lens.Micro.Aeson’
        ...plus three instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the second argument of ‘(^..)’, namely ‘values’
      In the expression: "[1, 2, 3]" ^.. values
      In an equation for ‘c’: c = "[1, 2, 3]" ^.. values
   |
24 | c = "[1, 2, 3]" ^.. values  -- [Number 1.0, Number 2.0, Number 3.0]
   |                     ^^^^^^

microlens-ex.hs:28:5: error:
    • Ambiguous type variable ‘s1’ arising from the literal ‘"[1, 2, 3]"’
      prevents the constraint ‘(Data.String.IsString
                                  s1)’ from being solved.
      Probable fix: use a type annotation to specify what ‘s1’ should be.
      These potential instances exist:
        instance Data.String.IsString Value
          -- Defined in ‘aeson-1.2.4.0:Data.Aeson.Types.Internal’
        instance Data.String.IsString Text -- Defined in ‘Data.Text’
        instance a ~ Char => Data.String.IsString [a]
          -- Defined in ‘Data.String’
        ...plus 8 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the first argument of ‘(^..)’, namely ‘"[1, 2, 3]"’
      In the expression: "[1, 2, 3]" ^.. values . _Double
      In an equation for ‘d’: d = "[1, 2, 3]" ^.. values . _Double
   |
28 | d = "[1, 2, 3]" ^.. values . _Double  -- [1.0, 2.0, 3.0]
   |     ^^^^^^^^^^^

microlens-ex.hs:28:21: error:
    • Ambiguous type variable ‘s1’ arising from a use of ‘values’
      prevents the constraint ‘(AsValue s1)’ from being solved.
      Probable fix: use a type annotation to specify what ‘s1’ should be.
      These potential instances exist:
        instance AsValue Value -- Defined in ‘Lens.Micro.Aeson’
        instance AsValue Text -- Defined in ‘Lens.Micro.Aeson’
        instance AsValue String -- Defined in ‘Lens.Micro.Aeson’
        ...plus three instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the first argument of ‘(.)’, namely ‘values’
      In the second argument of ‘(^..)’, namely ‘values . _Double’
      In the expression: "[1, 2, 3]" ^.. values . _Double
   |
28 | d = "[1, 2, 3]" ^.. values . _Double  -- [1.0, 2.0, 3.0]
   |                     ^^^^^^

microlens-ex.hs:49:5: error:
    • Ambiguous type variable ‘s0’ arising from the literal ‘"{\"a\":4,\"b\":7}"’
      prevents the constraint ‘(Data.String.IsString
                                  s0)’ from being solved.
      Probable fix: use a type annotation to specify what ‘s0’ should be.
      These potential instances exist:
        instance Data.String.IsString Value
          -- Defined in ‘aeson-1.2.4.0:Data.Aeson.Types.Internal’
        instance Data.String.IsString Text -- Defined in ‘Data.Text’
        instance a ~ Char => Data.String.IsString [a]
          -- Defined in ‘Data.String’
        ...plus 8 instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the first argument of ‘(^?)’, namely ‘"{\"a\":4,\"b\":7}"’
      In the expression: "{\"a\":4,\"b\":7}" ^? _Value
      In an equation for ‘h’: h = "{\"a\":4,\"b\":7}" ^? _Value
   |
49 | h = "{\"a\":4,\"b\":7}" ^? _Value
   |     ^^^^^^^^^^^^^^^^^^^

microlens-ex.hs:49:28: error:
    • Ambiguous type variable ‘s0’ arising from a use of ‘_Value’
      prevents the constraint ‘(AsValue s0)’ from being solved.
      Probable fix: use a type annotation to specify what ‘s0’ should be.
      These potential instances exist:
        instance AsValue Value -- Defined in ‘Lens.Micro.Aeson’
        instance AsValue Text -- Defined in ‘Lens.Micro.Aeson’
        instance AsValue String -- Defined in ‘Lens.Micro.Aeson’
        ...plus three instances involving out-of-scope types
        (use -fprint-potential-instances to see them all)
    • In the second argument of ‘(^?)’, namely ‘_Value’
      In the expression: "{\"a\":4,\"b\":7}" ^? _Value
      In an equation for ‘h’: h = "{\"a\":4,\"b\":7}" ^? _Value
   |
49 | h = "{\"a\":4,\"b\":7}" ^? _Value
   |                            ^^^^^^
Failed, no modules loaded.