Document BasicTypes

diff --git a/compiler/basicTypes/BasicTypes.lhs b/compiler/basicTypes/BasicTypes.lhs
index f782da3..aa1741c 100644 (file)
--- a/compiler/basicTypes/BasicTypes.lhs
+++ b/compiler/basicTypes/BasicTypes.lhs
@@ -372,17 +372,20 @@ the base of the module hierarchy.  So it seemed simpler to put the
 defn of OccInfo here, safely at the bottom
 
 \begin{code}
+-- | Identifier occurrence information
 data OccInfo 
-  = NoOccInfo          -- Many occurrences, or unknown
+  = NoOccInfo          -- ^ There are many occurrences, or unknown occurences
 
-  | IAmDead            -- Marks unused variables.  Sometimes useful for
+  | IAmDead            -- ^ Marks unused variables.  Sometimes useful for
                        -- lambda and case-bound variables.
 
-  | OneOcc             -- Occurs exactly once, not inside a rule
+  | OneOcc
        !InsideLam
        !OneBranch
-       !InterestingCxt
+       !InterestingCxt -- ^ Occurs exactly once, not inside a rule
 
+  -- | This identifier breaks a loop of mutually recursive functions. The field
+  -- marks whether it is only a loop breaker due to a reference in a rule
   | IAmALoopBreaker    -- Note [LoopBreaker OccInfo]
        !RulesOnly      -- True <=> This is a weak or rules-only loop breaker
                        --          See OccurAnal Note [Weak loop breakers]