[commit: ghc] master: Comments only (8249b50)

[git at git.haskell.org]

Repository : ssh://git@git.haskell.org/ghc

On branch  : master
Link       : http://ghc.haskell.org/trac/ghc/changeset/8249b509461c936d1d5fc6a81275d37fade5d1dc/ghc

>---------------------------------------------------------------

commit 8249b509461c936d1d5fc6a81275d37fade5d1dc
Author: Simon Peyton Jones <simonpj at microsoft.com>
Date:   Sun Jul 20 21:47:50 2014 +0100

    Comments only


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8249b509461c936d1d5fc6a81275d37fade5d1dc
 compiler/typecheck/TcSMonad.lhs | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/compiler/typecheck/TcSMonad.lhs b/compiler/typecheck/TcSMonad.lhs
index 898e2b8..9b73fe6 100644
--- a/compiler/typecheck/TcSMonad.lhs
+++ b/compiler/typecheck/TcSMonad.lhs
@@ -1559,6 +1559,8 @@ data XEvTerm
   = XEvTerm { ev_preds  :: [PredType]           -- New predicate types
             , ev_comp   :: [EvTerm] -> EvTerm   -- How to compose evidence
             , ev_decomp :: EvTerm -> [EvTerm]   -- How to decompose evidence
+            -- In both ev_comp and ev_decomp, the [EvTerm] is 1-1 with ev_preds
+            -- and each EvTerm has type of the corresponding EvPred
             }
 
 data MaybeNew = Fresh CtEvidence | Cached EvTerm
@@ -1645,16 +1647,16 @@ Note [xCFlavor]
 ~~~~~~~~~~~~~~~
 A call might look like this:
 
-    xCtFlavor ev subgoal-preds evidence-transformer
+    xCtEvidence ev evidence-transformer
 
-  ev is Given   => use ev_decomp to create new Givens for subgoal-preds,
+  ev is Given   => use ev_decomp to create new Givens for ev_preds,
                    and return them
 
-  ev is Wanted  => create new wanteds for subgoal-preds,
+  ev is Wanted  => create new wanteds for ev_preds,
                    use ev_comp to bind ev,
                    return fresh wanteds (ie ones not cached in inert_cans or solved)
 
-  ev is Derived => create new deriveds for subgoal-preds
+  ev is Derived => create new deriveds for ev_preds
                       (unless cached in inert_cans or solved)
 
 Note: The [CtEvidence] returned is a subset of the subgoal-preds passed in