Merge pull request #4369 from unisonweb/fix/pretty-printing

Fix parser issue caused by virtual semicolons being emitted inside parens
unisonweb · Nov 6, 2023 · ebc848a · ebc848a
2 parents 2d4215d + 4a43458
commit ebc848a
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Showing 3 changed files with 67 additions and 2 deletions.
diff --git a/unison-src/transcripts-round-trip/main.output.md b/unison-src/transcripts-round-trip/main.output.md
@@ -598,6 +598,37 @@ So we can see the pretty-printed output:
             _ -> 2
       go (SomethingUnusuallyLong "one" "two" "three")
     
+    stew_issue : ()
+    stew_issue =
+      error x = ()
+      a ++ b = 0
+      toText a = a
+      Debug : a -> b -> ()
+      Debug a b = ()
+      error (Debug None '(Debug "Failed " 42))
+    
+    stew_issue2 : ()
+    stew_issue2 =
+      error x = ()
+      a ++ b = 0
+      toText a = a
+      Debug : a -> b -> ()
+      Debug a b = ()
+      error (Debug None '("Failed " ++ toText 42))
+    
+    stew_issue3 : ()
+    stew_issue3 =
+      id x = x
+      error x = ()
+      a ++ b = 0
+      blah x y = 99
+      toText a = a
+      configPath = 0
+      Debug a b = ()
+      error
+        (Debug None '("Failed to get timestamp of config file "
+            ++ toText configPath))
+    
     test3 : '('('r))
     test3 = do
       run : Nat -> a

diff --git a/unison-src/transcripts-round-trip/reparses-with-same-hash.u b/unison-src/transcripts-round-trip/reparses-with-same-hash.u
@@ -492,4 +492,38 @@ fix_4258 x y z =
   _ = "fix_4258"
   ()
 
-fix_4258_example = fix_4258 1 () 2
+fix_4258_example = fix_4258 1 () 2
+
+-- previously, lexer was emitting virtual semicolons inside parens, which
+-- led to some very odd parse errors in cases like these
+
+stew_issue = 
+  error x = ()
+  (++) a b = 0
+  toText a = a
+  Debug : a -> b -> ()
+  Debug a b = ()
+  error
+    (Debug None '(Debug "Failed " -- virtual semicolon here was tripping up parser 
+                  42))
+stew_issue2 = 
+  error x = ()
+  (++) a b = 0
+  toText a = a
+  Debug : a -> b -> ()
+  Debug a b = ()
+  error
+    (Debug None '("Failed " ++ 
+           toText 42))
+
+stew_issue3 = 
+  id x = x
+  error x = ()
+  (++) a b = 0
+  blah x y = 99
+  toText a = a
+  configPath = 0
+  Debug a b = ()
+  error
+    (Debug None '("Failed to get timestamp of config file " ++ 
+           toText configPath))
diff --git a/unison-syntax/src/Unison/Syntax/Lexer.hs b/unison-syntax/src/Unison/Syntax/Lexer.hs
@@ -233,7 +233,7 @@ token'' tok p = do
     pops p = do
       env <- S.get
       let l = layout env
-      if top l == column p
+      if top l == column p && topBlockName l /= Just "(" -- don't emit virtual semis inside parens
         then pure [Token (Semi True) p p]
         else
           if column p > top l || topHasClosePair l