Newt in Newt compiles (but does not run)

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2025-01-04 09:26:33 -08:00
parent 46434cc555
commit 6b1eef86a7
21 changed files with 2970 additions and 91 deletions

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done/Lib/Compile.newt Normal file
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-- TODO Audit how much "outside" stuff could pile up in the continuation.
module Lib.Compile
import Lib.Types
import Lib.Prettier
import Lib.CompileExp
import Lib.TopContext
import Data.String
import Data.Maybe
import Data.Int
data StKind = Plain | Return | Assign String
JSStmt : StKind -> U
JSExp : U
data JAlt : U where
JConAlt : e. String -> JSStmt e -> JAlt
JDefAlt : e. JSStmt e -> JAlt
JLitAlt : e. JSExp -> JSStmt e -> JAlt
data JSExp : U where
LitArray : List JSExp -> JSExp
LitObject : List (String × JSExp) -> JSExp
LitString : String -> JSExp
LitInt : Int -> JSExp
Apply : JSExp -> List JSExp -> JSExp
Var : String -> JSExp
JLam : List String -> JSStmt Return -> JSExp
JUndefined : JSExp
Index : JSExp -> JSExp -> JSExp
Dot : JSExp -> String -> JSExp
data JSStmt : StKind -> U where
-- Maybe make this a snoc...
JSnoc : a. JSStmt Plain -> JSStmt a -> JSStmt a
JPlain : JSExp -> JSStmt Plain
JConst : (nm : String) -> JSExp -> JSStmt Plain
JReturn : JSExp -> JSStmt Return
JLet : (nm : String) -> JSStmt (Assign nm) -> JSStmt Plain -- need somebody to assign
JAssign : (nm : String) -> JSExp -> JSStmt (Assign nm)
-- TODO - switch to Int tags
-- FIXME add e to JAlt (or just drop it?)
JCase : a. JSExp -> List JAlt -> JSStmt a
-- throw can't be used
JError : a. String -> JSStmt a
Cont : StKind U
Cont e = JSExp -> JSStmt e
-- JSEnv contains `Var` for binders or `Dot` for destructured data. It
-- used to translate binders
record JSEnv where
constructor MkEnv
jsenv : List JSExp
depth : Int
-- this was like this, are we not using depth?
push : JSEnv -> JSExp -> JSEnv
push (MkEnv env depth) exp = MkEnv (exp :: env) depth
emptyJSEnv : JSEnv
emptyJSEnv = MkEnv Nil 0
litToJS : Literal -> JSExp
litToJS (LString str) = LitString str
litToJS (LChar c) = LitString $ pack (c :: Nil)
litToJS (LInt i) = LitInt i
-- Stuff nm.h1, nm.h2, ... into environment
-- TODO consider JSExp instead of nm, so we can have $foo.h1 instead of assigning a sc.
mkEnv : String -> Int -> JSEnv -> List String -> JSEnv
mkEnv nm k env Nil = env
mkEnv nm k env (x :: xs) = mkEnv nm (1 + k) (push env (Dot (Var nm) "h\{show k}")) xs
envNames : Env -> List String
-- given a name, find a similar one that doesn't shadow in Env
freshName : String -> JSEnv -> String
freshName nm env = if free env.jsenv nm then nm else go nm 1
where
free : List JSExp -> String -> Bool
free Nil nm = True
free (Var n :: xs) nm = if n == nm then False else free xs nm
free (_ :: xs) nm = free xs nm
go : String -> Int -> String
go nm k = let nm' = "\{nm}\{show k}" in if free env.jsenv nm' then nm' else go nm (1 + k)
freshName' : String -> JSEnv -> (String × JSEnv)
freshName' nm env =
let nm' = freshName nm env -- "\{nm}$\{show $ length env}"
env' = push env (Var nm')
in (nm', env')
freshNames : List String -> JSEnv -> (List String × JSEnv)
freshNames nms env = go nms env Lin
where
go : List Name -> JSEnv -> SnocList Name -> (List String × JSEnv)
go Nil env acc = (acc <>> Nil, env)
go (n :: ns) env acc =
let (n', env') = freshName' n env
in go ns env' (acc :< n')
-- This is inspired by A-normalization, look into the continuation monad
-- There is an index on JSStmt, adopted from Stefan Hoeck's code.
--
-- Here we turn a Term into a statement (which may be a sequence of statements), there
-- is a continuation, which turns the final JSExpr into a JSStmt, and the function returns
-- a JSStmt, wrapping recursive calls in JSnoc if necessary.
termToJS : ∀ e. JSEnv -> CExp -> Cont e -> JSStmt e
termToJS env (CBnd k) f = case getAt (cast k) env.jsenv of
(Just e) => f e
Nothing => fatalError "Bad bounds"
termToJS env CErased f = f JUndefined
termToJS env (CLam nm t) f =
let (nm',env') = freshName' nm env -- "\{nm}$\{show $ length env}"
in f $ JLam (nm' :: Nil) (termToJS env' t JReturn)
termToJS env (CFun nms t) f =
let (nms', env') = freshNames nms env
in f $ JLam nms' (termToJS env' t JReturn)
termToJS env (CRef nm) f = f $ Var nm
termToJS env (CMeta k) f = f $ LitString "META \{show k}"
termToJS env (CLit lit) f = f (litToJS lit)
-- if it's a var, just use the original
termToJS env (CLet nm (CBnd k) u) f = case getAt (cast k) env.jsenv of
Just e => termToJS (push env e) u f
Nothing => fatalError "bad bounds"
termToJS env (CLet nm t u) f =
let nm' = freshName nm env
env' = push env (Var nm')
-- If it's a simple term, use const
in case termToJS env t (JAssign nm') of
(JAssign _ exp) => JSnoc (JConst nm' exp) (termToJS env' u f)
t' => JSnoc (JLet nm' t') (termToJS env' u f)
termToJS env (CLetRec nm t u) f =
let nm' = freshName nm env
env' = push env (Var nm')
-- If it's a simple term, use const
in case termToJS env' t (JAssign nm') of
(JAssign _ exp) => JSnoc (JConst nm' exp) (termToJS env' u f)
t' => JSnoc (JLet nm' t') (termToJS env' u f)
termToJS env (CApp t args etas) f = termToJS env t (\ t' => (argsToJS t' args Lin f)) -- (f (Apply t' args'))))
where
etaExpand : JSEnv -> Nat -> SnocList JSExp -> JSExp -> JSExp
etaExpand env Z args tm = Apply tm (args <>> Nil)
etaExpand env (S etas) args tm =
let nm' = freshName "eta" env
env' = push env (Var nm')
in JLam (nm' :: Nil) $ JReturn $ etaExpand (push env (Var nm')) etas (args :< Var nm') tm
argsToJS : e. JSExp -> List CExp -> SnocList JSExp -> (JSExp -> JSStmt e) -> JSStmt e
argsToJS tm Nil acc k = k (etaExpand env (cast etas) acc tm)
-- k (acc <>> Nil)
argsToJS tm (x :: xs) acc k = termToJS env x (\ x' => argsToJS tm xs (acc :< x') k)
termToJS {e} env (CCase t alts) f =
-- need to assign the scrutinee to a variable (unless it is a var already?)
-- and add (Bnd -> JSExpr map)
-- TODO default case, let's drop the extra field.
termToJS env t $ \case
(Var nm) => maybeCaseStmt env nm alts
t' => do
-- TODO refactor nm to be a JSExp with Var{} or Dot{}
-- FIXME sc$ seemed to shadow something else, lets get this straightened out
-- we need freshName names that are not in env (i.e. do not play in debruijn)
let nm = "_sc$\{show env.depth}"
let env' = MkEnv env.jsenv (1 + env.depth)
JSnoc (JConst nm t') (maybeCaseStmt env' nm alts)
where
termToJSAlt : JSEnv -> String -> CAlt -> JAlt
termToJSAlt env nm (CConAlt name args u) = JConAlt name (termToJS (mkEnv nm 0 env args) u f)
-- intentionally reusing scrutinee name here
termToJSAlt env nm (CDefAlt u) = JDefAlt (termToJS (env) u f)
termToJSAlt env nm (CLitAlt lit u) = JLitAlt (litToJS lit) (termToJS env u f)
maybeCaseStmt : JSEnv -> String -> List CAlt -> JSStmt e
-- If there is a single alt, assume it matched
maybeCaseStmt env nm ((CConAlt _ args u) :: Nil) = (termToJS (mkEnv nm 0 env args) u f)
maybeCaseStmt env nm alts@(CLitAlt _ _ :: _) =
(JCase (Var nm) (map (termToJSAlt env nm) alts))
maybeCaseStmt env nm alts =
(JCase (Dot (Var nm) "tag") (map (termToJSAlt env nm) alts))
jsKeywords : List String
jsKeywords = (
"break" :: "case" :: "catch" :: "continue" :: "debugger" :: "default" :: "delete" :: "do" :: "else" ::
"finally" :: "for" :: "function" :: "if" :: "in" :: "instanceof" :: "new" :: "return" :: "switch" ::
"this" :: "throw" :: "try" :: "typeof" :: "var" :: "void" :: "while" :: "with" ::
"class" :: "const" :: "enum" :: "export" :: "extends" :: "import" :: "super" ::
"implements" :: "class" :: "let" :: "package" :: "private" :: "protected" :: "public" ::
"static" :: "yield" ::
"null" :: "true" :: "false" ::
-- might not be a big issue with namespaces on names now.
"String" :: "Number" :: "Array" :: "BigInt" :: Nil)
-- escape identifiers for js
jsIdent : String -> Doc
jsIdent id = if elem id jsKeywords then text ("$" ++ id) else text $ pack $ fix (unpack id)
where
fix : List Char -> List Char
fix Nil = Nil
fix (x :: xs) =
if isAlphaNum x || x == '_' then
x :: fix xs
-- make qualified names more readable
else if x == '.' then '_' :: fix xs
else if x == '$' then
'$' :: '$' :: fix xs
else
'$' :: (toHex (cast x)) ++ fix xs
stmtToDoc : e. JSStmt e -> Doc
expToDoc : JSExp -> Doc
expToDoc (LitArray xs) = fatalError "TODO - LitArray to doc"
expToDoc (LitObject xs) = text "{" <+> folddoc (\ a e => a ++ text ", " <+/> e) (map entry xs) <+> text "}"
where
entry : (String × JSExp) -> Doc
-- TODO quote if needed
entry (nm, exp) = jsIdent nm ++ text ":" <+> expToDoc exp
expToDoc (LitString str) = text $ quoteString str
expToDoc (LitInt i) = text $ show i
-- TODO add precedence
expToDoc (Apply x@(JLam _ _) xs) = text "(" ++ expToDoc x ++ text ")" ++ text "(" ++ nest 2 (commaSep (map expToDoc xs)) ++ text ")"
expToDoc (Apply x xs) = expToDoc x ++ text "(" ++ nest 2 (commaSep (map expToDoc xs)) ++ text ")"
expToDoc (Var nm) = jsIdent nm
expToDoc (JLam nms (JReturn exp)) = text "(" <+> commaSep (map jsIdent nms) <+> text ") =>" <+> text "(" ++ expToDoc exp ++ text ")"
expToDoc (JLam nms body) = text "(" <+> commaSep (map jsIdent nms) <+> text ") =>" <+> bracket "{" (stmtToDoc body) "}"
expToDoc JUndefined = text "undefined"
expToDoc (Index obj ix) = expToDoc obj ++ text "(" ++ expToDoc ix ++ text " :: Nil)"
expToDoc (Dot obj nm) = expToDoc obj ++ text "." ++ jsIdent nm
caseBody : e. JSStmt e -> Doc
caseBody stmt@(JReturn x) = nest 2 (line ++ stmtToDoc stmt)
-- caseBody {e = Return} stmt@(JCase{}) = nest 2 (line ++ stmtToDoc stmt)
caseBody {e} stmt@(JCase _ _) = nest 2 (line ++ stmtToDoc stmt </> text "break;")
caseBody stmt = line ++ text "{" ++ nest 2 (line ++ stmtToDoc stmt </> text "break;") </> text "}"
altToDoc : JAlt -> Doc
altToDoc (JConAlt nm stmt) = text "case" <+> text (quoteString nm) ++ text ":" ++ caseBody stmt
altToDoc (JDefAlt stmt) = text "default" ++ text ":" ++ caseBody stmt
altToDoc (JLitAlt a stmt) = text "case" <+> expToDoc a ++ text ":" ++ caseBody stmt
stmtToDoc (JSnoc x y) = stmtToDoc x </> stmtToDoc y
stmtToDoc (JPlain x) = expToDoc x ++ text ";"
-- I might not need these split yet.
stmtToDoc (JLet nm body) = text "let" <+> jsIdent nm ++ text ";" </> stmtToDoc body
stmtToDoc (JAssign nm expr) = jsIdent nm <+> text "=" <+> expToDoc expr ++ text ";"
stmtToDoc (JConst nm x) = text "const" <+> jsIdent nm <+> nest 2 (text "=" <+/> expToDoc x ++ text ";")
stmtToDoc (JReturn x) = text "return" <+> expToDoc x ++ text ";"
stmtToDoc (JError str) = text "throw new Error(" ++ text (quoteString str) ++ text ");"
stmtToDoc (JCase sc alts) =
text "switch (" ++ expToDoc sc ++ text ")" <+> bracket "{" (stack $ map altToDoc alts) "}"
mkArgs : Nat -> List String -> List String
mkArgs Z acc = acc
mkArgs (S k) acc = mkArgs k ("h\{show k}" :: acc)
dcon : QName -> Nat -> Doc
dcon qn@(QN ns nm) Z = stmtToDoc $ JConst (show qn) $ LitObject (("tag", LitString nm) :: Nil)
dcon qn@(QN ns nm) arity =
let args = mkArgs arity Nil
obj = ("tag", LitString nm) :: map (\x => (x, Var x)) args
in stmtToDoc $ JConst (show qn) (JLam args (JReturn (LitObject obj)))
-- use iife to turn stmts into expr
maybeWrap : JSStmt Return -> JSExp
maybeWrap (JReturn exp) = exp
maybeWrap stmt = Apply (JLam Nil stmt) Nil
entryToDoc : TopEntry -> M Doc
entryToDoc (MkEntry _ name ty (Fn tm)) = do
debug $ \ _ => "compileFun \{render 90 $ pprint Nil tm}"
ct <- compileFun tm
let exp = maybeWrap $ termToJS emptyJSEnv ct JReturn
pure $ text "const" <+> jsIdent (show name) <+> text "=" <+/> expToDoc exp ++ text ";"
entryToDoc (MkEntry _ name type Axiom) = pure $ text ""
entryToDoc (MkEntry _ name type (TCon strs)) = pure $ dcon name (piArity type)
entryToDoc (MkEntry _ name type (DCon arity str)) = pure $ dcon name (cast arity)
entryToDoc (MkEntry _ name type PrimTCon) = pure $ dcon name (piArity type)
entryToDoc (MkEntry _ name _ (PrimFn src _)) = pure $ text "const" <+> jsIdent (show name) <+> text "=" <+> text src
process : (List QName × List Doc) -> QName -> M (List QName × List Doc)
walkTm : Tm -> (List QName × List Doc) -> M (List QName × List Doc)
walkAlt : (List QName × List Doc) -> CaseAlt -> M (List QName × List Doc)
walkAlt acc (CaseDefault t) = walkTm t acc
walkAlt acc (CaseCons name args t) = walkTm t acc
walkAlt acc (CaseLit lit t) = walkTm t acc
walkTm (Ref x nm y) acc = process acc nm
walkTm (Lam x str _ _ t) acc = walkTm t acc
walkTm (App x t u) acc = walkTm u acc >>= walkTm t
walkTm (Pi x str icit y t u) acc = walkTm u acc >>= walkTm t
walkTm (Let x str t u) acc = walkTm u acc >>= walkTm t
walkTm (LetRec x str _ t u) acc = walkTm u acc >>= walkTm t
walkTm (Case x t alts) acc = foldlM walkAlt acc alts
walkTm _ acc = pure acc
-- This version (call `reverse ∘ snd <$> process "main" (Nil × Nil)`) will do dead
-- code elimination, but the Prelude js primitives are reaching for
-- stuff like True, False, MkUnit, fs which get eliminated
process (done,docs) nm = do
let (False) = elem nm done | _ => pure (done,docs)
top <- get
case lookup nm top of
Nothing => error emptyFC "\{show nm} not in scope"
Just entry@(MkEntry _ name ty (PrimFn src used)) => do
(done,docs) <- foldlM assign (nm :: done, docs) used
edoc <- entryToDoc entry
pure (done, edoc :: docs)
Just (MkEntry _ name ty (Fn tm)) => do
debug $ \ _ => "compileFun \{render 90 $ pprint Nil tm}"
ct <- compileFun tm
-- If ct has zero arity and is a compount expression, this fails..
let exp = maybeWrap $ termToJS emptyJSEnv ct JReturn
let doc = text "const" <+> jsIdent (show name) <+> text "=" <+/> expToDoc exp ++ text ";"
(done,docs) <- walkTm tm (nm :: done, docs)
pure (done, doc :: docs)
Just entry => do
edoc <- entryToDoc entry
pure (nm :: done, edoc :: docs)
where
assign : (List QName × List Doc) -> String -> M (List QName × List Doc)
assign (done, docs) nm = do
top <- get
case lookupRaw nm top of
Nothing => pure (done, docs)
(Just (MkEntry fc name type def)) => do
let tag = QN Nil nm
let (False) = elem tag done | _ => pure (done,docs)
(done,docs) <- process (done, docs) name
let doc = text "const" <+> jsIdent nm <+> text "=" <+> jsIdent (show name) ++ text ";"
pure (tag :: done, doc :: docs)
compile : M (List Doc)
compile = do
top <- get
case lookupRaw "main" top of
Just (MkEntry fc name type def) => do
tmp <- snd <$> process (Nil, Nil) name
let exec = stmtToDoc $ JPlain $ Apply (Var $ show name) Nil
pure $ reverse (exec :: tmp)
-- If there is no main, compile everything for the benefit of the playground
Nothing => do
top <- get
traverse entryToDoc $ map snd $ toList top.defs