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mirror of https://github.com/anoma/juvix.git synced 2024-12-17 11:51:42 +03:00
juvix/app/Commands/Format.hs
Jan Mas Rovira 2c8a364143
New syntax for function definitions (#2243)
- Closes #2060
- Closes #2189


- This pr adds support for the syntax described in #2189. It does not
drop support for the old syntax.

It is possible to automatically translate juvix files to the new syntax
by using the formatter with the `--new-function-syntax` flag. E.g.

```
juvix format --in-place --new-function-syntax
```
# Syntax changes
Type signatures follow this pattern:
```
f (a1 : Expr) .. (an : Expr) : Expr
```
where each `ai` is a non-empty list of symbols. Braces are used instead
of parentheses when the argument is implicit.

Then, we have these variants:
1. Simple body. After the signature we have `:= Expr;`.
2. Clauses. The function signature is followed by a non-empty sequence
of clauses. Each clause has the form:
```
| atomPat .. atomPat := Expr
```
# Mutual recursion
Now identifiers **do not need to be defined before they are used**,
making it possible to define mutually recursive functions/types without
any special syntax.
There are some exceptions to this. We cannot forward reference a symbol
`f` in some statement `s` if between `s` and the definition of `f` there
is one of the following statements:
1. Local module
2. Import statement
3. Open statement

I think it should be possible to drop the restriction for local modules
and import statements
2023-07-10 19:57:55 +02:00

111 lines
4.0 KiB
Haskell

module Commands.Format where
import Commands.Base
import Commands.Format.Options
import Data.Text qualified as Text
import Juvix.Formatter
import Juvix.Prelude.Pretty
data FormatNoEditRenderMode
= ReformattedFile (NonEmpty AnsiText)
| InputPath (Path Abs File)
| Silent
data FormatRenderMode
= EditInPlace FormattedFileInfo
| NoEdit FormatNoEditRenderMode
data FormatTarget
= TargetFile (Path Abs File)
| TargetProject (Path Abs Dir)
| TargetStdin
isTargetProject :: FormatTarget -> Bool
isTargetProject = \case
TargetProject {} -> True
_ -> False
targetFromOptions :: Members '[Embed IO, App] r => FormatOptions -> Sem r FormatTarget
targetFromOptions opts = do
globalOpts <- askGlobalOptions
let isStdin = globalOpts ^. globalStdin
f <- mapM filePathToAbs (opts ^. formatInput)
pkgDir <- askPkgDir
case f of
Just (Left p) -> return (TargetFile p)
Just Right {} -> return (TargetProject pkgDir)
Nothing -> do
isPackageGlobal <- askPackageGlobal
if
| isStdin -> return TargetStdin
| not (isPackageGlobal) -> return (TargetProject pkgDir)
| otherwise -> do
printFailureExit $
Text.unlines
[ "juvix format error: either 'JUVIX_FILE_OR_PROJECT' or '--stdin' option must be specified",
"Use the --help option to display more usage information."
]
runCommand :: forall r. Members '[Embed IO, App, Resource, Files] r => FormatOptions -> Sem r ()
runCommand opts = do
target <- targetFromOptions opts
let newSyntax = NewSyntax (opts ^. formatNewSyntax)
runOutputSem (renderFormattedOutput target opts) $ runScopeFileApp $ do
res <- runReader newSyntax $ case target of
TargetFile p -> format p
TargetProject p -> formatProject p
TargetStdin -> formatStdin
let exitFail :: IO a
exitFail = exitWith (ExitFailure 1)
case res of
FormatResultFail -> embed exitFail
FormatResultNotFormatted ->
{- use exit code 1 for
* unformatted files when using --check
* when running the formatter on a Juvix project
-}
when (opts ^. formatCheck || isTargetProject target) (embed exitFail)
FormatResultOK -> pure ()
renderModeFromOptions :: FormatTarget -> FormatOptions -> FormattedFileInfo -> FormatRenderMode
renderModeFromOptions target opts formattedInfo
| opts ^. formatInPlace = whenContentsModified (EditInPlace formattedInfo)
| opts ^. formatCheck = NoEdit Silent
| otherwise = case target of
TargetFile {} -> NoEdit (ReformattedFile (formattedInfo ^. formattedFileInfoContentsAnsi))
TargetProject {} -> whenContentsModified (NoEdit (InputPath (formattedInfo ^. formattedFileInfoPath)))
TargetStdin -> NoEdit (ReformattedFile (formattedInfo ^. formattedFileInfoContentsAnsi))
where
whenContentsModified :: FormatRenderMode -> FormatRenderMode
whenContentsModified res
| formattedInfo ^. formattedFileInfoContentsModified = res
| otherwise = NoEdit Silent
renderFormattedOutput :: forall r. Members '[Embed IO, App, Resource, Files] r => FormatTarget -> FormatOptions -> FormattedFileInfo -> Sem r ()
renderFormattedOutput target opts fInfo = do
let renderMode = renderModeFromOptions target opts fInfo
outputResult renderMode
where
outputResult :: FormatRenderMode -> Sem r ()
outputResult = \case
EditInPlace i@FormattedFileInfo {..} ->
runTempFileIO
. restoreFileOnError _formattedFileInfoPath
$ writeFile' _formattedFileInfoPath (i ^. formattedFileInfoContentsText)
NoEdit m -> case m of
ReformattedFile ts -> forM_ ts renderStdOut
InputPath p -> say (pack (toFilePath p))
Silent -> return ()
runScopeFileApp :: Member App r => Sem (ScopeEff ': r) a -> Sem r a
runScopeFileApp = interpret $ \case
ScopeFile p -> do
let appFile =
AppPath
{ _pathPath = mkPrepath (toFilePath p),
_pathIsInput = False
}
runPipeline appFile upToScoping
ScopeStdin -> runPipelineNoFile upToScoping