update to fix cases of no discriminants

koka-lang · Jul 12, 2024 · 7a4b5ee · 7a4b5ee
1 parent f8d000e
commit 7a4b5ee
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Showing 5 changed files with 19 additions and 25 deletions.
diff --git a/src/Core/MatchMerge.hs b/src/Core/MatchMerge.hs
@@ -151,7 +151,7 @@ splitBranchConstructors' b@(Branch ps _) branches =
           --   ++ show (vcat (text (show accP) : map (text . show) ps')) 
           --   ++ "\nis\n" ++ show (vcat (map (text . show) patNews)) 
           --   ++ "\nwith new discriminators" ++ show newVars ++ "\n") $ return ()
-          if all isSimpleMatch patNews then
+          if all isSimpleMatch patNews || all null newVars then -- If there are no discriminators we assume they don't match because the guard distinguishes
             -- Didn't match the current branch (i.e. returned a trivial common superstructure - just wildcards / vars), keep the old pattern
             -- Add the new branch to the list of branches that don't match any subpattern
             return (bs', b':bs2', matchAnys, discriminators, accP)

diff --git a/test/parc/parc15.kk b/test/parc/parc15.kk
@@ -1,6 +1,6 @@
 fun test(xs:list<int>, y:int) {
   match(xs) {
-    Cons(x as 0) ->
+    Cons(x) ->
       /* dup x; drop y */
       match(xs) {
         Cons -> /* drop xs */ x

diff --git a/test/parc/parc15.kk.out b/test/parc/parc15.kk.out
@@ -21,14 +21,12 @@ import std/core = std/core = "";
 pub fun test : (xs : list<int>, y : int) -> int
  = fn(xs: list<int>, y: int){
  match (xs) {
- (std/core/types/Cons(((@skip std/core/types/@Box((@case40: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
+ (std/core/types/Cons(((@skip std/core/types/@Box((x: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
  -> val _ : int
- = std/core/types/@dup(@case40);
+ = std/core/types/@dup(x);
  val _ : ()
  = std/core/types/@drop(y);
- (match (@case40) {
- 0
- -> (match (xs) {
+ (match (xs) {
  (std/core/types/Cons(((@skip std/core/types/@Box((@pat@xxx: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
  -> val _ : ()
  = (match ((std/core/types/@is-unique(xs))) {
@@ -47,14 +45,16 @@ pub fun test : (xs : list<int>, y : int) -> int
  = std/core/types/@dec-ref(xs);
  std/core/types/Unit;
  });
- @case40;
+ x;
  (@skip std/core/types/Nil() : (list<int>) )
  -> val _ : ()
- = std/core/types/@drop(@case40);
+ = std/core/types/@drop(x);
  2;
  });
- _
+ (std/core/types/Cons(((@skip std/core/types/@Box((@pat@xxx: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
  -> val _ : ()
+ = std/core/types/@drop(y);
+ val _ : ()
  = (match ((std/core/types/@is-unique(xs))) {
  (std/core/types/True() : bool )
  -> val _ : ()
@@ -71,10 +71,7 @@ pub fun test : (xs : list<int>, y : int) -> int
  = std/core/types/@dec-ref(xs);
  std/core/types/Unit;
  });
- val _ : ()
- = std/core/types/@drop(@case40);
  2;
- });
  (@skip std/core/types/Nil() : (list<int>) )
  -> y;
  };

diff --git a/test/parc/parc16.kk b/test/parc/parc16.kk
@@ -1,7 +1,7 @@
 fun test(xs:list<int>, y:int, z:int) {
   // drop z
   match(xs) {
-    Cons(x as 0) ->
+    Cons(x) ->
       // dup x; drop y
       match(xs) {
         Cons -> /* drop xs */ x

diff --git a/test/parc/parc16.kk.out b/test/parc/parc16.kk.out
@@ -23,14 +23,12 @@ pub fun test : (xs : list<int>, y : int, z : int) -> int
  val _ : ()
  = std/core/types/@drop(z);
  match (xs) {
- (std/core/types/Cons(((@skip std/core/types/@Box((@case40: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
+ (std/core/types/Cons(((@skip std/core/types/@Box((x: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
  -> val _ : int
- = std/core/types/@dup(@case40);
+ = std/core/types/@dup(x);
  val _ : ()
  = std/core/types/@drop(y);
- (match (@case40) {
- 0
- -> (match (xs) {
+ (match (xs) {
  (std/core/types/Cons(((@skip std/core/types/@Box((@pat@xxx: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
  -> val _ : ()
  = (match ((std/core/types/@is-unique(xs))) {
@@ -49,14 +47,16 @@ pub fun test : (xs : list<int>, y : int, z : int) -> int
  = std/core/types/@dec-ref(xs);
  std/core/types/Unit;
  });
- @case40;
+ x;
  (@skip std/core/types/Nil() : (list<int>) )
  -> val _ : ()
- = std/core/types/@drop(@case40);
+ = std/core/types/@drop(x);
  2;
  });
- _
+ (std/core/types/Cons(((@skip std/core/types/@Box((@pat@xxx: int)) : @Box ) as @box-xxx: @Box), (@pat@xxx: list<int>)) : list<int> )
  -> val _ : ()
+ = std/core/types/@drop(y);
+ val _ : ()
  = (match ((std/core/types/@is-unique(xs))) {
  (std/core/types/True() : bool )
  -> val _ : ()
@@ -73,10 +73,7 @@ pub fun test : (xs : list<int>, y : int, z : int) -> int
  = std/core/types/@dec-ref(xs);
  std/core/types/Unit;
  });
- val _ : ()
- = std/core/types/@drop(@case40);
  2;
- });
  (@skip std/core/types/Nil() : (list<int>) )
  -> y;
  };