xvm VS ghc

Parts of Ecstasy are now implemented in Ecstasy. Here's the Lexer, for example.

Ecstasy

A Future reference has the various capabilities that you'd imagine, taking lambdas for thenDo(), whenComplete(), etc. The reference, in the above example, is a local variable, so you just obtain it using the C-style & operator:

FWIW - here is the stage manager code that I referred to.

Ecstasy (xtclang.org): Currently working on session management for a cloud-based HTTP back end. Not exactly compiler or language stuff, but it certainly is exercising the compiler and language.

I prefer to make my AST nodes fairly rich, and let them do the brunt of the work themselves. Instead of the 5 lines of code above, the assignment statement node in Ecstasy is over 1000 LOC. But it handles everything from initial validation through the MLIR emission.

No, not that specific project. It's our own Mid Level Intermediate Representation (or Mid Level Intermediate Language), aka MLIR/MLIL. Here's a snapshot of the operators.

Ecstasy project on Github: https://github.com/xtclang/xvm

Quite a few improvements in Ecstasy over the past month:

Early on, we had the This keyword, and its meaning was "this type". So if a method on class Collection was declared as This add(Element), it meant that the method returned the auto-narrowing type of this. We later changed it from This to Collection (or whatever the class name is) and added the Collection! (non-narrowing) form, because there were syntactic needs (e.g. inner and outer auto-narrowing class references) that could not be covered by This. We evaluated a few different options, and we liked (and still like) the result that we came up with. That said, I still wish we had a This keyword (see the 5th bullet point) for the "this type", but 🤷‍♂️.

[email protected] % cat > File.hs pred 1 = 4 succ 4 = 1 succ 1 = 2 [email protected] % ghci -XNoImplicitPrelude File.hs GHCi, version 9.0.2: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf [1 of 1] Compiling Main ( File.hs, interpreted ) Ok, one module loaded. (0.04 secs,) GHCi> pred 1 4 it :: GHC.Num.Num p => p (0.01 secs, 79,688 bytes) GHCi> succ 1 2 it :: GHC.Num.Num p => p (0.01 secs, 78,088 bytes)

GHCi, version 9.0.2: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf GHCi> :{ GHCi| pred 1 = 4 GHCi| succ 4 = 1 GHCi| succ 1 = 2 GHCi| :} pred :: (Eq a, Num a, Num p) => a -> p succ :: (Eq a, Num a, Num p) => a -> p (0.04 secs, 0 bytes) GHCi> pred 1 4 it :: Num p => p (0.01 secs, 62,784 bytes) GHCi> succ 4 1 it :: Num p => p (0.01 secs, 61,864 bytes) GHCi> succ 1 2 it :: Num p => p (0.01 secs, 61,928 bytes)

[jumper deriving-trans @master]$ nix develop [jumper deriving-trans @master]$ cabal repl Build profile: -w ghc-9.2.4 -O1 In order, the following will be built (use -v for more details): - deriving-trans-0.8.0.0 (lib) (first run) Preprocessing library for deriving-trans-0.8.0.0.. GHCi, version 9.2.4: https://www.haskell.org/ghc/ :? for help :1:1: warning: [-Wmissing-local-signatures] Polymorphic local binding with no type signature: _compileParsedExpr :: forall {a}. ghc-prim:GHC.Types.IO a -> ghc-prim:GHC.Types.IO a macro 'doc' overwrites builtin command. Use ':def!' to overwrite. Loaded GHCi configuration from /home/jumper/.ghc/ghci.conf : warning: [-Wunused-packages] The following packages were specified via -package or -package-id flags, but were not needed for compilation: - unliftio-core-0.2.0.1-4aEaNp8xHRK6Ey6KEoq0BU - transformers-base-0.4.6-BO3yqj8kK7N1FV1bV9s5yP - transformers-0.6.0.4-F8uVRiS1g8K3h8Rsxr0UMd - resourcet-1.2.6-GkviYKmTWlu24k3qS4ih9J - random-1.2.1.1-DsRhotp5Bx34wv1CRGomTB - primitive-0.7.3.0-1lmZ3PZm6JAE7HP2AgnD1I - mtl-2.3.1-A9dQ96c1wA8f1tgidK0Kj - monad-control-identity-0.2.0.0-C96eAiqAq5HPusYxrNzzr - monad-control-1.0.3.1-9k4XD0NyvERHbSFKJZxIuC - logict-0.8.0.0-5sZNS401Hrq2OkYkpVhzEI - exceptions-0.10.7-LidfE6miSbs6Y1NYj1lBV5 - base-4.16.3.0 [1 of 7] Compiling Control.Monad.Accum.OrphanInstances ( src/Control/Monad/Accum/OrphanInstances.hs, interpreted ) [2 of 7] Compiling Control.Monad.Select.OrphanInstances ( src/Control/Monad/Select/OrphanInstances.hs, interpreted ) [3 of 7] Compiling Control.Monad.Trans.Elevator ( src/Control/Monad/Trans/Elevator.hs, interpreted ) [4 of 7] Compiling Control.Monad.Trans.Compose.Transparent ( src/Control/Monad/Trans/Compose/Transparent.hs, interpreted ) [5 of 7] Compiling Control.Monad.Trans.Compose ( src/Control/Monad/Trans/Compose.hs, interpreted ) [6 of 7] Compiling Control.Monad.Trans.Compose.Stack ( src/Control/Monad/Trans/Compose/Stack.hs, interpreted ) [7 of 7] Compiling Control.Monad.Trans.Compose.Infix ( src/Control/Monad/Trans/Compose/Infix.hs, interpreted ) Ok, 7 modules loaded. λ *Control.Monad.Trans.Compose > :set -XPartialTypeSignatures λ *Control.Monad.Trans.Compose > import Control.Monad.Trans.Compose.Infix λ *Control.Monad.Trans.Compose Control.Monad.Trans.Compose.Infix > import Control.Monad.Trans.Compose.Transparent λ *Control.Monad.Trans.Compose Control.Monad.Trans.Compose.Infix Control.Monad.Trans.Compose.Transparent > runTransparentT ./> (`Mtl.T.runReaderT` 'a') ./> (`Mtl.T.runReaderT` True) $ (,) <$> (Mtl.ask :: _ Char) <*> (Mtl.ask :: _ Bool) :4:98: warning: [-Wpartial-type-signatures] • Found type wildcard ‘_’ standing for ‘ComposeT (Mtl.T.ReaderT Bool) (ComposeT (Mtl.T.ReaderT Char) (Elevator NoT)) IO :: * -> *’ • In the type ‘_ Char’ In an expression type signature: _ Char In the second argument of ‘(<$>)’, namely ‘(Mtl.ask :: _ Char)’ :4:98: warning: [-Wmonomorphism-restriction] • The Monomorphism Restriction applies to the binding for ‘’ Consider giving it a type signature • In the second argument of ‘(<$>)’, namely ‘(Mtl.ask :: _ Char)’ In the first argument of ‘(<*>)’, namely ‘(,) <$> (Mtl.ask :: _ Char)’ In the second argument of ‘($)’, namely ‘(,) <$> (Mtl.ask :: _ Char) <*> (Mtl.ask :: _ Bool)’ :4:122: warning: [-Wpartial-type-signatures] • Found type wildcard ‘_’ standing for ‘ComposeT (Mtl.T.ReaderT Bool) (ComposeT (Mtl.T.ReaderT Char) (Elevator NoT)) IO :: * -> *’ • In the type ‘_ Bool’ In an expression type signature: _ Bool In the second argument of ‘(<*>)’, namely ‘(Mtl.ask :: _ Bool)’ :4:122: warning: [-Wmonomorphism-restriction] • The Monomorphism Restriction applies to the binding for ‘’ Consider giving it a type signature • In the second argument of ‘(<*>)’, namely ‘(Mtl.ask :: _ Bool)’ In the second argument of ‘($)’, namely ‘(,) <$> (Mtl.ask :: _ Char) <*> (Mtl.ask :: _ Bool)’ In the first argument of ‘GHC.GHCi.ghciStepIO :: IO a -> IO a’, namely ‘(runTransparentT ./> (`Mtl.T.runReaderT` 'a') ./> (`Mtl.T.runReaderT` True) $ (,) <$> (Mtl.ask :: _ Char) <*> (Mtl.ask :: _ Bool))’ ('a',True)

GHCi, version 8.10.7: https://www.haskell.org/ghc/ :? for help

Haskell (in the form of GHC) uses Alex, which is regular expression-based.

A good starting point for the JS backend is the module-level documentation in GHC.StgToJS, but it doesn't look like there's much good documentation yet, no.

GHCi, version 9.4.2: https://www.haskell.org/ghc/ :? for help ghci> :load Evolution.hs [1 of 2] Compiling Main ( Evolution.hs, interpreted ) Ok, one module loaded. ghci> :t fac four fac four :: Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ (Succ Zero)))))))))))))))))))))))

[email protected] % ghci GHCi, version 8.8.4: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf GHCi> :t foldMap foldMap :: (Foldable t, Monoid m) => (a -> m) -> t a -> m GHCi> :t fold :1:1: error: • Variable not in scope: fold • Perhaps you meant one of these: ‘foldl’ (imported from Prelude), ‘foldr’ (imported from Prelude) GHCi> :t Data.Foldable.fold Data.Foldable.fold :: (Foldable t, Monoid m) => t m -> m GHCi> :t foldMap id foldMap id :: (Foldable t, Monoid m) => t m -> m

% ghci GHCi, version 8.8.4: https://www.haskell.org/ghc/ :? for help Loaded GHCi configuration from /home/bss/.ghc/ghci.conf GHCi> import Control.Applicative (liftA3) (0.00 secs, 0 bytes) GHCi> import Data.Bool (bool) (0.00 secs, 0 bytes) GHCi> liftA3 bool (* 2) (`div` 2) even 4 2 it :: Integral t => t (0.01 secs, 60,272 bytes)

“I was a maintainer for Haddock. It's the de facto standard documentation tooling for Haskell. And I also contributed to the core build system called Cabal and also contributed a few small patches to GHC itself, as well as, all the ecosystem around it."