X-Git-Url: http://git.megacz.com/?a=blobdiff_plain;f=ghc%2Fcompiler%2Ftypecheck%2FTcRnTypes.lhs;fp=ghc%2Fcompiler%2Ftypecheck%2FTcRnTypes.lhs;h=50258cc75e0e904faa8a92eaf92a7ec08e31efe6;hb=1dfb756e01201c62ddde93010b3384d4d9644ad6;hp=33190e798768fc0c01be73acdc82ae3135a8ef79;hpb=eace8501f73b0b2ee55e02d84e45cec03ab898d7;p=ghc-hetmet.git

diff --git a/ghc/compiler/typecheck/TcRnTypes.lhs b/ghc/compiler/typecheck/TcRnTypes.lhs
index 33190e7..50258cc 100644
--- a/ghc/compiler/typecheck/TcRnTypes.lhs
+++ b/ghc/compiler/typecheck/TcRnTypes.lhs
@@ -361,7 +361,8 @@ topSpliceStage = Splice (topLevel - 1)	-- Stage for the body of a top-level spli
 ---------------------------
 
 -- In arrow notation, a variable bound by a proc (or enclosed let/kappa)
--- is not in scope to the left of an arrow tail (-<).  For example
+-- is not in scope to the left of an arrow tail (-<) or the head of (|..|).
+-- For example
 --
 --	proc x -> (e1 -< e2)
 --
@@ -369,7 +370,7 @@ topSpliceStage = Splice (topLevel - 1)	-- Stage for the body of a top-level spli
 -- a bit complicated:
 --
 --	let x = 3 in
---	prox y -> (proc z -> e1) -< e2
+--	proc y -> (proc z -> e1) -< e2
 --
 -- Here, x and z are in scope in e1, but y is not.  Here's how we track this:
 --	a) Assign an "proc level" to each proc, being the number of
@@ -378,7 +379,8 @@ topSpliceStage = Splice (topLevel - 1)	-- Stage for the body of a top-level spli
 --	   enclosing proc.
 --	c) Keep a list of out-of-scope procs.  When moving to the left of
 --	   an arrow-tail, add the proc-level of the immediately enclosing
---	   proc to the list.
+--	   proc to the list, and increment the proc-level so that variables
+--	   bound inside the expression are in scope.
 --	d) When looking up a variable, complain if its proc-level is in
 --	   the banned list