[#1175] Empty Entity Parsing

[parsonsmatt]

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• Documented new APIs with Haddock markup
• Added @since declarations to the Haddock

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• Update the Changelog.md file with a link to your PR
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Fixes #1175

---

Currently just a failing test. I should really get this fixed soon.

[parsonsmatt]

Test failure message:

  test/main.hs:316:13:
  1) #1175 empty entity associateLines works
       Actual list is not a permutation of expected list!
         expected list contains:   [LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "Foo" :|
 []} :| [Line {lineIndent = 4, tokens = "name" :| ["String"]},Line {lineIndent = 4, tokens = "age" :| ["I
nt"]}], lwcComments = []}, LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "EmptyEntity" :|
[]} :| [], lwcComments = []}, LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "Bar" :| []} :
| [Line {lineIndent = 4, tokens = "name" :| ["String"]}], lwcComments = []}, LinesWithComments {lwcLines
= Line {lineIndent = 0, tokens = "Baz" :| []} :| [Line {lineIndent = 4, tokens = "a" :| ["Int"]},Line {li
neIndent = 4, tokens = "b" :| ["String"]},Line {lineIndent = 4, tokens = "c" :| ["FooId"]}], lwcComments
= []}]
         actual list contains:     [LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "Foo" :|
 []} :| [Line {lineIndent = 4, tokens = "name" :| ["String"]},Line {lineIndent = 4, tokens = "age" :| ["I
nt"]}], lwcComments = []}, LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "EmptyEntity" :|
[]} :| [Line {lineIndent = 0, tokens = "Bar" :| []},Line {lineIndent = 4, tokens = "name" :| ["String"]}]
, lwcComments = []}, LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "Baz" :| []} :| [Line {
lineIndent = 4, tokens = "a" :| ["Int"]},Line {lineIndent = 4, tokens = "b" :| ["String"]},Line {lineInde
nt = 4, tokens = "c" :| ["FooId"]}], lwcComments = []}]
         the missing elements are: [LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "EmptyEn
tity" :| []} :| [], lwcComments = []}, LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "Bar"
 :| []} :| [Line {lineIndent = 4, tokens = "name" :| ["String"]}], lwcComments = []}]
         the extra elements are:   [LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "EmptyEn
tity" :| []} :| [Line {lineIndent = 0, tokens = "Bar" :| []},Line {lineIndent = 4, tokens = "name" :| ["S
tring"]}], lwcComments = []}]

Or, with formatting,

expected =
    [ LinesWithComments
        {lwcLines = Line {lineIndent = 0, tokens = "Foo" :|
     []} :| [Line {lineIndent = 4, tokens = "name" :| ["String"]},Line {lineIndent = 4, tokens = "age" :| ["I
    nt"]}], lwcComments = []}, LinesWithComments {lwcLines = Line {lineIndent = 0, tokens = "EmptyEntity" :|
    []} :| [], lwcComments = []}
    , LinesWithComments
        {lwcLines = Line {lineIndent = 0, tokens = "Bar" :| []} : | [Line {lineIndent = 4, tokens = "name" :| ["String"]}], lwcComments = []}
    , LinesWithComments
        { lwcLines =
            Line {lineIndent = 0, tokens = "Baz" :| []} :|
                [ Line
                    { lineIndent = 4
                    , tokens = "a" :| ["Int"]
                    }
                , Line
                    { lineIndent = 4
                    , tokens = "b" :| ["String"]
                    }
                , Line {lineIndent = 4, tokens = "c" :| ["FooId"]}]
        , lwcComments = []
        }
]

actual =
    [ LinesWithComments
        { lwcLines =
            Line { lineIndent = 0 , tokens = "Foo" :| [] } :|
                [ Line { lineIndent = 4, tokens = "name" :| ["String"]}
                , Line { lineIndent = 4, tokens = "age" :| ["Int"]}
                ]
        , lwcComments = []
        }
    , LinesWithComments
        { lwcLines =
            Line {lineIndent = 0, tokens = "EmptyEntity" :| []} :|
                [ Line {lineIndent = 0, tokens = "Bar" :| []}
                , Line {lineIndent = 4, tokens = "name" :| ["String"]}
                ]
        , lwcComments = []
        }
    , LinesWithComments
        { lwcLines = Line {lineIndent = 0, tokens = "Baz" :| []} :|
            [ Line { lineIndent = 4, tokens = "a" :| ["Int"]}
            , Line {lineIndent = 4, tokens = "b" :| ["String"]}
            , Line {lineIndent = 4, tokens = "c" :| ["FooId"]}
            ]
        , lwcComments = []
        }
    ]

missing =
        [ LinesWithComments
            { lwcLines = Line {lineIndent = 0, tokens = "EmptyEntity" :| []} :| []
            , lwcComments = []
            }
        , LinesWithComments
            { lwcLines = Line {lineIndent = 0, tokens = "Bar":| []} :| [Line {lineIndent = 4, tokens = "name" :| ["String"]}]
            , lwcComments = []
            }
        ]

extra =
    [ LinesWithComments
        { lwcLines = Line {lineIndent = 0, tokens = "EmptyEntity" :| []} :|
            [ Line {lineIndent = 0, tokens = "Bar" :| []}
            , Line {lineIndent = 4, tokens = "name" :| ["String"]}
            ]
        , lwcComments = []
        }
    ]

So, what's happening is that the parser is recognizing the syntax and combining EmptyEntity and Bar into a single LinesWIthComments record, when in reality, they should be split.

[parsonsmatt]

By using Debug.traceShowId, I'm able to determine the exact cause of the problem in associateLines:

associateLines :: [Line' NonEmpty] -> [LinesWithComments]
associateLines lines =
    foldr combine [] $
    Debug.traceShowId $
    foldr toLinesWithComments [] lines
  where

So the problem occurs in toLinesWIthComments.