WIP start cleanup

Author: LPTK

hkmc2/shared/src/main/scala/hkmc2/semantics/Elaborator.scala

@@ -56,6 +56,7 @@ object Elaborator:
     case NotInFunction
     case Forbidden
 
+  /** Context used to keep track of underscores representing lambda shorthands, eg `_ + 1`. */
   class UnderCtx(val unders: Opt[mutable.ArrayBuffer[VarSymbol]])
 
   case class Ctx(outer: OuterCtx, parent: Opt[Ctx], env: Map[Str, Ctx.Elem], 

hkmc2/shared/src/main/scala/hkmc2/semantics/ucs/Desugarer.scala

@@ -246,7 +246,6 @@ class Desugarer(val elaborator: Elaborator)(using UnderCtx)
         ):
           nominate(ctx, finish(term(headCoda)(using ctx))):
             expandMatch(_, headPattern, tailSplit)(fallback)
-    // ! WARNING: this is just slop generated by Copilot. TODO: rewrite
     case tree @ OpApp(lhs, opIdent @ Ident(opName), rhss) => fallback => ctx => trace(
       pre = s"termSplit: after op <<< $opName",
       post = (res: Split) => s"termSplit: after op >>> $res"
@@ -320,45 +319,6 @@ class Desugarer(val elaborator: Elaborator)(using UnderCtx)
           case rhs => ctx =>
             raise(ErrorReport(msg"Unrecognized operator branch." -> rhs.toLoc :: Nil))
             elabFallback(ctx)
-    // TODO: BEGIN rm
-    case tree @ App(lhs, blk @ OpBlock(opRhsApps)) => fallback => ctx =>
-      nominate(ctx, finish(term(lhs)(using ctx))): vs =>
-        val mkInnerFinish = (op: Term) => (rhsTerm: Term) =>
-          val first = Fld(FldFlags.empty, vs.ref(/* FIXME ident? */), N)
-          val second = Fld(FldFlags.empty, rhsTerm, N)
-          val rawTup = Tup(lhs :: Nil): Tup // <-- loc might be wrong
-          val arguments = Term.Tup(first :: second :: Nil)(rawTup)
-          val joint = FlowSymbol("‹applied-result›")
-          Term.App(op, arguments)(tree, N, joint)
-        opRhsApps.foldRight(Function.const(fallback): Sequel): (tt, elabFallback) =>
-          tt match
-          case (Tree.Empty(), LetLike(`let`, pat, termTree, N)) => ctx =>
-            val ident = pat match // TODO handle patterns and rm special cases
-              case ident: Ident => ident
-              case und: Under => new Ident("_").withLocOf(und)
-              case _ => ???
-            termTree match
-            case S(termTree) =>
-              val sym = VarSymbol(ident)
-              val fallbackCtx = ctx + (ident.name -> sym)
-              Split.Let(sym, term(termTree)(using ctx), elabFallback(fallbackCtx))
-          case (Tree.Empty(), Modified(Keyword.`do`, doLoc, computation)) => ctx => trace(
-            pre = s"termSplit: do $computation",
-            post = (res: Split) => s"termSplit: else >>> $res"
-          ):
-            val sym = TempSymbol(N, "doTemp")
-            Split.Let(sym, term(computation)(using ctx), elabFallback(ctx))
-          case (Tree.Empty(), Modified(Keyword.`else`, elsLoc, default)) => ctx =>
-            // TODO: report `rest` as unreachable
-            Split.default(term(default)(using ctx))
-          case ((rawOp @ Ident(_)), rhs) => ctx =>
-            val op = term(rawOp)(using ctx)
-            val innerFinish = mkInnerFinish(op)
-            termSplit(rhs, innerFinish)(elabFallback(ctx))(ctx)
-          case (op, rhs) => ctx =>
-            raise(ErrorReport(msg"Unrecognized operator branch." -> op.toLoc :: Nil))
-            elabFallback(ctx)
-    // TODO: END rm
     case _ => fallback => _ =>
       raise(ErrorReport(msg"Unrecognized term split (${tree.describe})." -> tree.toLoc :: Nil))
       fallback.withoutLoc // Hacky... a loc is always added for the result

hkmc2/shared/src/main/scala/hkmc2/semantics/ucs/package.scala

@@ -4,9 +4,9 @@ package semantics
 import sourcecode.{Name, Line, FileName}
 
 package object ucs:
-  def error(using Line, FileName)(msgs: (Message, Option[Loc])*)(using Raise)(using Name): Unit =
+  def error(using Line, FileName)(msgs: (Message, Option[Loc])*)(using Raise, Name): Unit =
     raise(ErrorReport(msgs.toList))
 
-  def warn(using Line, FileName)(msgs: (Message, Option[Loc])*)(using Raise)(using Name): Unit =
+  def warn(using Line, FileName)(msgs: (Message, Option[Loc])*)(using Raise, Name): Unit =
     raise(WarningReport(msgs.toList))
 end ucs

hkmc2/shared/src/main/scala/hkmc2/syntax/Tree.scala

@@ -80,8 +80,6 @@ enum Tree extends AutoLocated:
   case IfLike(kw: Keyword.`if`.type | Keyword.`while`.type, kwLoc: Opt[Loc], split: Tree)
   case SplitPoint()
   case OpSplit(lhs: Tree, ops_rhss: Ls[Tree]) // the rhss trees are expressions rooted in `SplitPoint`s
-  @deprecated("Use If instead", "hkmc2-ucs")
-  case IfElse(cond: Tree, alt: Tree)
   case Case(kwLoc: Opt[Loc], branches: Tree)
   case Region(name: Tree, body: Tree)
   case RegRef(reg: Tree, value: Tree)
@@ -90,10 +88,9 @@ enum Tree extends AutoLocated:
   case Spread(kw: Keyword.Ellipsis, kwLoc: Opt[Loc], body: Opt[Tree])
   case Annotated(annotation: Tree, target: Tree)
   case Constructor(decl: Tree)
-  /** It represents a term that has already been elaborated. When desugaring the
-   *  operator splits in UCS, the `lhs` of `OpSplit` has already been elaborated
-   *  into a `Term`, we need to embed `Term` into `Tree` using `Trm`.
-   */
+  /** Represents a term that has already been elaborated. When desugaring
+   *  operator splits in the UCS, the `lhs` of `OpSplit` has already been elaborated
+   *  into a `Term`, so we need to embed `Term` into `Tree` using `Trm`. */
   case Trm(term: semantics.Term)
 
   def splitOn(acc: Tree): Tree = this match
@@ -105,7 +102,7 @@ enum Tree extends AutoLocated:
     case InfixApp(lhs, kw, rhs) => InfixApp(lhs.splitOn(acc), kw, rhs)
     case _: (Ident | Literal | Error) => acc
 
-  def children: Ls[Tree] = this match
+  def children: Ls[Located] = this match
     case _: Empty | _: Error | _: Ident | _: Literal | _: Under | _: Unt => Nil
     case Pun(_, e) => e :: Nil
     case Bra(_, e) => e :: Nil
@@ -129,7 +126,6 @@ enum Tree extends AutoLocated:
     case TermDef(k, head, rhs) => head :: rhs.toList
     case New(body, rft) => body.toList ::: rft.toList
     case IfLike(_, _, split) => split :: Nil
-    case IfElse(cond, alt) => cond :: alt :: Nil
     case Case(_, bs) => Ls(bs)
     case Region(name, body) => name :: body :: Nil
     case RegRef(reg, value) => reg :: value :: Nil
@@ -150,7 +146,7 @@ enum Tree extends AutoLocated:
     case Dummy => Nil
     case OpSplit(lhs, ops_rhss) => lhs :: ops_rhss
     case SplitPoint() => Nil
-    case Trm(_) => Nil
+    case Trm(trm) => trm :: Nil
 
   def describe: Str = this match
     case Empty() => "empty"
@@ -175,9 +171,7 @@ enum Tree extends AutoLocated:
     case Tup(fields) => "tuple"
     case TyTup(tys) => "type tuple"
     case App(lhs, rhs) => "application"
-    case OpApp(lhs, op, rhss) => "operator application" + (op match
-      case Ident(nme) => s" `$nme`"
-      case _ => "")
+    case OpApp(lhs, op, rhss) => "operator application"
     case Jux(lhs, rhs) => "juxtaposition"
     case Sel(prefix, name) => "selection"
     case SynthSel(prefix, name) => "synthetic selection"
@@ -200,9 +194,8 @@ enum Tree extends AutoLocated:
     case Constructor(_) => "constructor"
     case MemberProj(_, _) => "member projection"
     case Keywrd(kw) => s"'${kw.name}' keyword"
-    case Unt() => "unit"
     case Dummy => "‹dummy›"
-    case Trm(_) => "term"
+    case Trm(t) => t.describe + " term"
 
   def deparenthesized: Tree = this match
     case Bra(BracketKind.Round, inner) => inner.deparenthesized

hkmc2/shared/src/test/mlscript/backlog/UCS.mls

@@ -122,7 +122,7 @@ if 1 + 1
 //│ ╔══[PARSE ERROR] Expected end of input; found literal instead
 //│ ║  l.107: 	    * 2 == 4 then "X"
 //│ ╙──       	           ^
-//│ ═══[ERROR] Unrecognized term split (term).
+//│ ═══[ERROR] Unrecognized term split (reference term).
 //│ ╔══[ERROR] Unrecognized term split (integer literal).
 //│ ║  l.107: 	    * 2 == 4 then "X"
 //│ ╙──       	      ^

hkmc2/shared/src/test/mlscript/bbml/bbBasics.mls

@@ -130,7 +130,7 @@ let t = new Some(true) in t.Some#value
 //│ ╔══[LEXICAL ERROR] Expect at least one digit after the  decimal point
 //│ ║  l.129: 	42.Some#value
 //│ ╙──       	   ^
-//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application `#`).
+//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application).
 //│ ║  l.129: 	42.Some#value
 //│ ╙──       	   ^^^^^^^^^^
 //│ Type: Num

hkmc2/shared/src/test/mlscript/codegen/Juxtapositions.mls

@@ -125,7 +125,7 @@ inc(2) * 2
 42
   inc() * 1
     add(2)
-//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application `*`).
+//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application).
 //│ ║  l.126: 	  inc() * 1
 //│ ║         	  ^^^^^^^^^
 //│ ║  l.127: 	    add(2)
@@ -148,7 +148,7 @@ inc(2) * 2
 :todo // ?
 42
   inc() + 1
-//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application `+`).
+//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application).
 //│ ║  l.150: 	  inc() + 1
 //│ ╙──       	  ^^^^^^^^^
 //│ = 42
@@ -157,7 +157,7 @@ inc(2) * 2
 42
   add(2) + 1
   inc()
-//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application `+`).
+//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application).
 //│ ║  l.158: 	  add(2) + 1
 //│ ╙──       	  ^^^^^^^^^^
 //│ = 43
@@ -166,7 +166,7 @@ inc(2) * 2
 42
   add(2)
   inc() + 1
-//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application `+`).
+//│ ╔══[ERROR] Illegal juxtaposition right-hand side (operator application).
 //│ ║  l.168: 	  inc() + 1
 //│ ╙──       	  ^^^^^^^^^
 //│ = 44

hkmc2/shared/src/test/mlscript/handlers/Debugging.mls

@@ -184,28 +184,16 @@ let res =
   Runtime.try(() => Test.main())
 //│ res = EffectHandle()
 
-res
-//│ = EffectHandle()
-
 :re
 res.raise()
 //│ ═══[RUNTIME ERROR] Error: Unhandled effect Handler$h$
 
-res
-//│ = EffectHandle()
-
 set res = res.resumeWith(42)
 
-res
-//│ = EffectHandle()
-
 :re
 res.raise()
 //│ ═══[RUNTIME ERROR] Error: Unhandled effect Handler$h$
 
-res
-//│ = EffectHandle()
-
 res.resumeWith(666)
 //│ = 0.33676533676533676
 
@@ -223,9 +211,9 @@ fun f() =
 f()
 //│ > [FnLocalsInfo("‹top level›", [LocalVarInfo("i", 100)]), FnLocalsInfo("f", [LocalVarInfo("j", 200)])]
 //│ > Stack Trace:
-//│ > 	at f (Debugging.mls:216:3) with locals: j=200
+//│ > 	at f (Debugging.mls:204:3) with locals: j=200
 //│ > Stack Trace:
-//│ > 	at f (Debugging.mls:218:3)
+//│ > 	at f (Debugging.mls:206:3)
 //│ > Stack Trace:
-//│ > 	at f (Debugging.mls:219:3) with locals: j=300
+//│ > 	at f (Debugging.mls:207:3) with locals: j=300
 //│ > [FnLocalsInfo("‹top level›", [LocalVarInfo("i", 100)]), FnLocalsInfo("f", [LocalVarInfo("j", 300)])]

hkmc2/shared/src/test/mlscript/rp/RangePatterns.mls

@@ -58,7 +58,7 @@ pattern UnsignedByte = 0..< 256
 //│ ╔══[ERROR] Name not found: .<
 //│ ║  l.51: 	pattern UnsignedByte = 0..< 256
 //│ ╙──      	                         ^^
-//│ ╔══[ERROR] Unrecognized pattern (operator application `.<`)
+//│ ╔══[ERROR] Unrecognized pattern (operator application)
 //│ ║  l.51: 	pattern UnsignedByte = 0..< 256
 //│ ╙──      	                       ^^^^^^^^