brittany often fails on files with TemplateHaskell #206

New Issue

2018-12-15T16:50:48+01:00

dspies-leapyear commented

2018-12-15 16:50:48 +01:00

(Migrated from github.com)

Unfortunately I don't know exactly what's causing it because it doesn't seem to fails on all files which use TemplateHaskell, but it does seem to happen on a lot of them.

On
0d98f92420/persistwrap-table/test/PersistWrap/TableSpec.hs

I get
brittanyCmd: HsSpliceTy{} Brittany error - invalid output

Unfortunately I don't know exactly what's causing it because it doesn't seem to fails on _all_ files which use TemplateHaskell, but it _does_ seem to happen on a lot of them. On https://github.com/dspies-leapyear/persistwrap/blob/0d98f924208e2f4936e06c0b28ac5d223812c0fe/persistwrap-table/test/PersistWrap/TableSpec.hs I get `brittanyCmd: HsSpliceTy{} Brittany error - invalid output`

👍 1

tfausak commented

2019-06-18 04:01:46 +02:00

(Migrated from github.com)

Can you provide a smaller failing example? There's a lot going on in that file. It's not clear what the problem could be.

charlescrain commented

2019-10-02 23:39:30 +02:00

(Migrated from github.com)

I got this error whenever brittany puts some template haskell on its own line.

Ex:


import           Data.FileEmbed                 ( embedStringFile , makeRelativeToProject)
import           Data.Text                            ( Text )

data Example = Example { longExampleRecordName :: Text }

mkExampleWithTH = Example
  { longExampleRecordName     = $(embedStringFile =<< makeRelativeToProject "./example/with/long/path/to/file")
  }

gets formatted to

mkExampleWithTH = Example
  { longExampleRecordName =
    $(embedStringFile =<< makeRelativeToProject "./example/with/long/path/to/file")
  }

and then whenever I attempt to format, it errors with:

ERROR: encountered unknown syntactical constructs: HsSpliceE{}

If written so that the TH isn't at the beginning of line, it works fine, so there is a work around.

I got this error whenever brittany puts some template haskell on its own line. Ex: ```haskell import Data.FileEmbed ( embedStringFile , makeRelativeToProject) import Data.Text ( Text ) data Example = Example { longExampleRecordName :: Text } mkExampleWithTH = Example { longExampleRecordName = $(embedStringFile =<< makeRelativeToProject "./example/with/long/path/to/file") } ``` gets formatted to ```haskell mkExampleWithTH = Example { longExampleRecordName = $(embedStringFile =<< makeRelativeToProject "./example/with/long/path/to/file") } ``` and then whenever I attempt to format, it errors with: ``` ERROR: encountered unknown syntactical constructs: HsSpliceE{} ``` If written so that the TH isn't at the beginning of line, it works fine, so there is a work around.

👍 1

ghorn commented

2019-10-03 00:38:16 +02:00

(Migrated from github.com)

I can reproduce this as well with a slightly different example:

{-# LANGUAGE QuasiQuotes #-}

module Test
  ( foo
  ) where

foo :: String
foo =
  [fmt|this causes error|]

gives this error:

ERROR: brittany pretty printer returned syntactically invalid result.
ERROR: encountered unknown syntactical constructs:
HsSpliceE{} at Test.hs:9:3-26

If the quasiquote is on the same line as foo = then there is no error.

I can reproduce this as well with a slightly different example: ```haskell {-# LANGUAGE QuasiQuotes #-} module Test ( foo ) where foo :: String foo = [fmt|this causes error|] ``` gives this error: ``` ERROR: brittany pretty printer returned syntactically invalid result. ERROR: encountered unknown syntactical constructs: HsSpliceE{} at Test.hs:9:3-26 ``` If the quasiquote is on the same line as `foo =` then there is no error.

andys8 commented

2020-03-24 14:22:12 +01:00

(Migrated from github.com)

Another example:

Fails

f = case parse of
  Left  err  -> error (formatErr err)
  Right res -> res
 where
  parse = lexAndParse
    "File"
    $(runIO (readFile "prelude/File.ext") >>= \x -> [| x |])

HsSpliceE{} at src/Bot/Dsl/Prelude.hs:25:5-63
make: *** [Makefile:106: format] Error 1

Working

f = case parse of
  Left  err  -> error (formatErr err)
  Right res -> res
 where
  content = $(runIO (readFile "prelude/File.ext") >>= \x -> [| x |])
  parse = lexAndParse "File" content

Another example: ### Fails ```hs f = case parse of Left err -> error (formatErr err) Right res -> res where parse = lexAndParse "File" $(runIO (readFile "prelude/File.ext") >>= \x -> [| x |]) ``` ```shell HsSpliceE{} at src/Bot/Dsl/Prelude.hs:25:5-63 make: *** [Makefile:106: format] Error 1 ``` ### Working ```hs f = case parse of Left err -> error (formatErr err) Right res -> res where content = $(runIO (readFile "prelude/File.ext") >>= \x -> [| x |]) parse = lexAndParse "File" content ```

tfausak commented

2020-03-24 19:22:28 +01:00

(Migrated from github.com)

Here's a minimal example:

{-# language TemplateHaskell #-}
module I206 where
x = $( works )
y =
 $( doesn't work )

$ stack exec -- brittany --version
brittany version 0.12.1.1
Copyright (C) 2016-2019 Lennart Spitzner
Copyright (C) 2019 PRODA LTD
There is NO WARRANTY, to the extent permitted by law.

$ stack exec -- brittany --output-on-errors I206.hs
ERROR: brittany pretty printer returned syntactically invalid result.
ERROR: encountered unknown syntactical constructs:
HsSpliceE{} at I206.hs:5:2-18
{-# language TemplateHaskell #-}
module I206 where
x = $( works )
y = {- BRITTANY ERROR UNHANDLED SYNTACTICAL CONSTRUCT -}

You can work around this by adding a -- brittany-disable-next-binding comment above the troublesome splice.

{-# language TemplateHaskell #-}
module I206 where
x = $( works )
-- brittany-disable-next-binding
y =
 $( doesn't work )

I wasn't able to reproduce the error with quasi quotes.

Here's a minimal example: ``` hs {-# language TemplateHaskell #-} module I206 where x = $( works ) y = $( doesn't work ) ``` ``` sh $ stack exec -- brittany --version brittany version 0.12.1.1 Copyright (C) 2016-2019 Lennart Spitzner Copyright (C) 2019 PRODA LTD There is NO WARRANTY, to the extent permitted by law. ``` ``` sh $ stack exec -- brittany --output-on-errors I206.hs ERROR: brittany pretty printer returned syntactically invalid result. ERROR: encountered unknown syntactical constructs: HsSpliceE{} at I206.hs:5:2-18 {-# language TemplateHaskell #-} module I206 where x = $( works ) y = {- BRITTANY ERROR UNHANDLED SYNTACTICAL CONSTRUCT -} ``` You can work around this by adding a `-- brittany-disable-next-binding` comment above the troublesome splice. ``` hs {-# language TemplateHaskell #-} module I206 where x = $( works ) -- brittany-disable-next-binding y = $( doesn't work ) ``` I wasn't able to reproduce the error with quasi quotes.

majkrzak commented

2020-06-11 22:05:13 +02:00

(Migrated from github.com)

I'm not exactly sure if it is related or should be spearated issue, but when trying to format:

get "/" $ do
  setHeader "Content-Type" "text/html"
  raw $ fromStrict $(embedFile "app/index.html")

I'm getting ...ct $ (em... which results in broken code

I'm not exactly sure if it is related or should be spearated issue, but when trying to format: ```haskell get "/" $ do setHeader "Content-Type" "text/html" raw $ fromStrict $(embedFile "app/index.html") ``` I'm getting ...`ct $ (em`... which results in broken code

tfausak commented

2021-11-29 03:21:30 +01:00

(Migrated from github.com)

To fix the embedFile problem you need to let Brittany know that the TemplateHaskell language extension is enabled. You can do that by either adding the {-# LANGUAGE TemplateHaskell #-} pragma to the file, or calling Brittany with --ghc-options -XTemplateHaskell.

To fix the `embedFile` problem you need to let Brittany know that the `TemplateHaskell` language extension is enabled. You can do that by either adding the `{-# LANGUAGE TemplateHaskell #-}` pragma to the file, or calling Brittany with `--ghc-options -XTemplateHaskell`.

Sign in to join this conversation.

No Milestone

No project

No Assignees

1 Participants

Notifications

Due Date

The due date is invalid or out of range. Please use the format 'yyyy-mm-dd'.

No due date set.

Dependencies

No dependencies set.

Reference: hexagoxel/brittany#206