Forbid { field, ... } record patterns.

why

• readability and error prone-ness: Similar to exposing from an import, it becomes hard to follow where a certain value originated from

  checkForConcatOnMap { nodeRange, firstArg } =
      case toSpecificCall ( "List", "map" ) firstArg of
          Just { fnRange } ->
              let ...
              in
              Fix.replaceByExpression nodeRange firstArg
                  ++ Fix.replace fnRange "List.concatMap"
  
  
          Nothing ->
              Nothing

  Since fnRange, nodeRange and firstArg could have all come from either call, it's really hard to trace their origin without jumping around in your code.

  checkForConcatOnMap concatCall =
      case toSpecificCall ( "List", "map" ) concatCall.firstArg of
          Just mapCall ->
              let ...
              in
              Fix.replaceByExpression concatCall.nodeRange concatCall.firstArg
                  ++ Fix.replace mapCall.fnRange "List.concatMap"
  
  
          Nothing ->
              Nothing

  Here it's always very clear what thing a field refers to. Don't you agree this is much easier to understand?

• less syntax to learn to use right and keep in your head

• name clashes: Using record destructuring relies on the assumption that no values with the same name will ever in the lifetime of this file be introduced.

  module Ui exposing (icon)
  
  
  icon { image, style } =
      ...

  future iteration

  module Ui exposing (icon, image)
  
  
  image { proportions, url } =
      ...
  
  
  icon { image, style } =
      ...

  Ok, we have to change this one completely unrelated field into a record access. That's not too bad.

  module Ui exposing (icon, image)
  
  
  image { proportions, url } =
      ...
  
  
  icon ({ style } as config) =
      ...

  future iteration

  module Ui exposing (icon, image, url)
  
  
  image { proportions, url } =
      ...
  
  
  icon ({ style } as config) =
      ...
  
  
  url { path, openInNewTab } =
      ...

  Oh well, another clash

  module Ui exposing (icon, image, url)
  
  
  image ({ proportions } as config) =
      ...
  
  
  icon ({ style } as config) =
      ...
  
  
  url { path, openInNewTab } =
      ...

  This mixed use of record access and record destructuring is quite ugly I'd say. Maybe just use record access consistently so you don't have these problems?

• leaves potential future need to refactor: You can't really use record destructuring anywhere except at the most outer argument/let level because the field names quickly lose context and introduce name clashes.

  checkForConcatOnMap { nodeRange, firstArg } =
      case toSpecificCall ( "List", "map" ) firstArg of
          Just { fnRange, nodeRange } ->
              let ...
              in
              Fix.replaceByExpression nodeRange nodeRange -- well...
                  ++ Fix.replace fnRange "List.concatMap"
  
  
          Nothing ->
              Nothing