From 45c380d1b77198449fb8e3beadb39dc8f77abb72 Mon Sep 17 00:00:00 2001
From: Tuncer Ayaz <tuncer.ayaz@gmail.com>
Date: Tue, 20 Apr 2010 20:44:45 +0200
Subject: Document R14 paren-less record access/update

Add a section to the reference manual describing the R14
change to not require parentheses when accessing or updating
fields in nested records.

Signed-off-by: Tuncer Ayaz <tuncer.ayaz@gmail.com>
---
 system/doc/reference_manual/records.xml | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)

(limited to 'system/doc/reference_manual')

diff --git a/system/doc/reference_manual/records.xml b/system/doc/reference_manual/records.xml
index e2fe5fe8de..e901b7bccf 100644
--- a/system/doc/reference_manual/records.xml
+++ b/system/doc/reference_manual/records.xml
@@ -144,6 +144,29 @@ is_person(_P) ->
       unbound variables.</p>
   </section>
 
+  <section>
+    <title>Nested records</title>
+    <p>Beginning with R14 parentheses when accessing or updating nested
+      records can be omitted. Assuming we have the following record
+      definitions:</p>
+    <pre>
+-record(nrec0, {name = "nested0"}).
+-record(nrec1, {name = "nested1", nrec0=#nrec0{}}).
+-record(nrec2, {name = "nested2", nrec1=#nrec1{}}).
+
+N2 = #nrec2{},
+    </pre>
+    <p>Before R14 you would have needed to use parentheses as following:</p>
+    <pre>
+"nested0" = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0.name,
+N0n = ((N2#nrec2.nrec1)#nrec1.nrec0)#nrec0{name = "nested0a"},
+    </pre>
+    <p>Since R14 you can also write:</p>
+    <pre>
+"nested0" = N2#nrec2.nrec1#nrec1.nrec0#nrec0.name,
+N0n = N2#nrec2.nrec1#nrec1.nrec0#nrec0{name = "nested0a"},</pre>
+  </section>
+
   <section>
     <title>Internal Representation of Records</title>
     <p>Record expressions are translated to tuple expressions during
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