Skip to content

Add Enum class, instances and [x..] [x..y] sugar #139

New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Merged
chrisdone-artificial merged 4 commits into from
Aug 12, 2026
+31 −0
Merged

Add Enum class, instances and [x..] [x..y] sugar #139

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
4 commits
Select commit Hold shift + click to select a range
efae14c
Add Enum.enumFrom/Enum.enumFromTo
Aug 12, 2026
2d5fdf6
Add instances of Enum for Int/Integer/Day/DayOfWeek/Bool/Char
Aug 12, 2026
7c64eea
Add syntactic sugar for [x..] and [x..y]
Aug 12, 2026
151f3b7
Add example
Aug 12, 2026
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
12 changes: 12 additions & 0 deletions examples/45-enum.hell
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -0,0 +1,12 @@
main = do
IO.print $ List.take 5 $ Enum.enumFrom 1
IO.print $ Enum.enumFromTo 1 10
IO.print $ List.take 5 $ Enum.enumFrom 'a'
IO.print $ List.take 5 $ Enum.enumFrom Bool.False
IO.print $ List.take 5 $ Enum.enumFrom (Int.toInteger 1)
IO.print $ List.take 5 $ Enum.enumFrom $
Maybe.maybe (Error.error "Bad day.") Function.id $ Day.fromGregorianValid (Int.toInteger 2020) 01 01

-- simple list generators
IO.print [1 .. 3]
IO.print $ List.take 5 ['a' ..]
19 changes: 19 additions & 0 deletions src/Hell.hs
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -904,6 +904,12 @@ instances =
instance0 @Ord @Text,
instance0 @Ord @ByteString,
instance0 @Ord @ExitCode,
instance0 @Enum @Int,
instance0 @Enum @Integer,
instance0 @Enum @Day,
instance0 @Enum @DayOfWeek,
instance0 @Enum @Bool,
instance0 @Enum @Char,
instance0 @Monad @IO,
instance0 @Monad @Maybe,
instance0 @Monad @[],
Expand Down Expand Up @@ -1226,6 +1232,15 @@ desugarExp userDefinedTypeAliases globals = go mempty
squash _ = Left BadDoNotation
squash stmts >>= go scope
HSE.RecConstr _ qname fields -> go scope $ makeConstructRecord qname fields
-- generators sugars
HSE.EnumFromTo l from to -> do
let enumFromTo' = HSE.Var l (HSE.Qual l (HSE.ModuleName l "Enum") (HSE.Ident l "enumFromTo"))
go scope $
HSE.App l (HSE.App l enumFromTo' from) to
HSE.EnumFrom l from -> do
let enumFrom' = HSE.Var l (HSE.Qual l (HSE.ModuleName l "Enum") (HSE.Ident l "enumFrom"))
go scope $ HSE.App l enumFrom' from
-- end of generator sugars
e -> Left $ UnsupportedSyntax $ show e

-- | Handles both user-defined case and primitive type case (Maybe, Either, etc.)
Expand Down Expand Up @@ -2184,6 +2199,10 @@ polyLits =
"Ord.lt" (Ord.<) :: forall a. (Ord a) => a -> a -> Bool
"Ord.gt" (Ord.>) :: forall a. (Ord a) => a -> a -> Bool

-- Enum
"Enum.enumFrom" enumFrom :: forall a. Enum a => a -> [a]
"Enum.enumFromTo" enumFromTo :: forall a. Enum a => a -> a -> [a]

-- Tuples
"Tuple.(,)" (,) :: forall a b. a -> b -> (a, b)
"Tuple.(,)" (,) :: forall a b. a -> b -> (a, b)
Expand Down