Fix computation of never-Nothing indicator nn

1 files changed, 4 insertions, 3 deletions

diff --git a/src/c.bqn b/src/c.bqn
index 1093cf61..1827d563 100644
--- a/src/c.bqn
+++ b/src/c.bqn
@@ -220,8 +220,8 @@ Parse ← {r‿vn‿i‿e‿def←𝕨⋄nv←≠vn
   "Nothing (·) cannot be assigned"_nerr ne×a
   oa←⌽/hf<op←(er<2)∧r≥2⋄ro←op∨«op∧m2←r=3    # op: active modifiers; ro: mod or right operand
   "Missing operand"_nerr op×2(«⌈m2×»)no⌈2×m2≥ro∨r∊↕2
-  s←𝕩=sep⋄fo←𝕩=2+⊑bB⋄ls←s∧fo<○IT lo←𝕩=4+⊑bB # List Separators: after ⟨lo, not {fo
-  fc←𝕩=1+⊑bH
+  s←𝕩=sep⋄fo←𝕩∊⟨2+⊑bB,1+⊑bH⟩                # Separators, function open { or ;
+  ls←s∧fo<○IT lo←𝕩=4+⊑bB                    # List Separators: after ⟨lo, not {fo
   "Can't use Nothing (·) in lists"_nerr ne×»lo∨ls
   "Double subjects (missing ‿?)"_err_(G) ∧⟜«ro»⊸∨⊸<r=0
   ma←tr<(𝕩=2+⊑bG)∧«ir≥1                     # Modified assignment
@@ -235,6 +235,7 @@ Parse ← {r‿vn‿i‿e‿def←𝕨⋄nv←≠vn
   fw←H gi⊏nx                                # Bodies where 𝕨 must be defined
   {"Can't return Nothing (·)"_err_(𝕩⊏⍋∘Rev) 2=fw⌈↩nf¬⊸×𝕩⊏nr} 1-˜0∾cc⊏rev
   "Invalid use of 𝕨 in monadic case"_err_(/CB) 1↓fw∧cw=0
+  fw∨↩2=cw
   nn←fo+`⊸⊏fw⋄no(⊣-=)↩nn⋄ne(⊣-=)↩nn         # fw indicates 𝕨 is never Nothing
   "Assignment target must be a name or list of targets"_err_(G) (a∨aid∨ps∨𝕩(=⟜(3+⊑)<M)bB)<aa
   "Can't nest assignments (write aliases with ⇐)"_err_(ai⊏G) (ak=2)<ai⊏aa
@@ -282,7 +283,7 @@ Parse ← {r‿vn‿i‿e‿def←𝕨⋄nv←≠vn
   cn←pi∾lt←/𝕩≥cl←vi+nv⋄ob∾↩(cl-˜≠u)+lt⊏𝕩    # Constants
   bk←c⊏gi                                   # Block loads
   ll←sll∾˜(¬lo/1«ps)+-⟜»1↓(lo∾1)/+`ls∾0     # List Length
-  dr←/s>(2=ne)∨ls∨»r=¯5⋄rt←/fo∨fc           # Drop (block separator) and return
+  dr←/s>(2=ne)∨ls∨»r=¯5⋄rt←/fo              # Drop (block separator) and return
   fl←(dy×⊏⟜os)⊸+fa+dy                       # Function application site
   dr∾↩((1+dy)×fn←2=fm←fa⊏ne)/fl             # Turn function applications on · to drops
   fn↩¬fn⋄fa/˜↩fn⋄fl/˜↩fn                    # And remove them