From 5c38ded1a699a06da954610323574af284fe2738 Mon Sep 17 00:00:00 2001
From: Matthijs Kooijman <matthijs@stdin.nl>
Date: Thu, 27 Aug 2009 13:46:35 +0200
Subject: [PATCH] Update normal form example.

---
 Chapters/Normalization.tex | 38 +++++++++++++++++++++++---------------
 1 file changed, 23 insertions(+), 15 deletions(-)

diff --git a/Chapters/Normalization.tex b/Chapters/Normalization.tex
index a8194de..2acd1c8 100644
--- a/Chapters/Normalization.tex
+++ b/Chapters/Normalization.tex
@@ -62,27 +62,35 @@ An example of a program in canonical form would be:
 
 \startlambda
   -- All arguments are an inital lambda
-  λx.λc.λd.
-  -- There is one let expression at the top level
+  λa.λd.λsp.
+  -- There are nested let expressions at top level
   let
+    -- Unpack the state by coercion
+    s = sp :: (Word, Word)
+    -- Extract both registers from the state
+    r1 = case s of (fst, snd) -> fst
+    r2 = case s of (fst, snd) -> snd
     -- Calling some other user-defined function.
-    s = foo x
-    -- Extracting result values from a tuple
-    a = case s of (a, b) -> a
-    b = case s of (a, b) -> b
-    -- Some builtin expressions
-    rh = add c d
-    rhh = sub d c
+    d' = foo d
     -- Conditional connections
-    rl = case b of
-      High -> rhh
+    out = case a of
+      High -> r1
+      Low -> r2
+    r1' = case a of
+      High -> d
+      Low -> r1
+    r2' = case a of
+      High -> r2
       Low -> d
-    r = case a of
-      High -> rh
-      Low -> rl
+    -- Packing a tuple
+    s' = (,) r1' r2'
+    -- Packing the state by coercion
+    sp' = s' :: State (Word, Word)
+    -- Pack our return value
+    res = (,) sp' out
   in
     -- The actual result
-    r
+    res
 \stoplambda
 
 When looking at such a program from a hardware perspective, the top level
-- 
2.30.2