From 2d429e75ce69e77f8c95490ac03881ec9aa0354a Mon Sep 17 00:00:00 2001
From: Marti Bolivar <mbolivar@mit.edu>
Date: Mon, 25 Oct 2010 21:15:28 -0400
Subject: arduino language reference nearing completion, properly CC-BY-SA 3.0
 attributed

---
 source/arduino/scope.rst | 63 +++++++++++++++++++++++++-----------------------
 1 file changed, 33 insertions(+), 30 deletions(-)

(limited to 'source/arduino/scope.rst')

diff --git a/source/arduino/scope.rst b/source/arduino/scope.rst
index bb56246..0e793ec 100644
--- a/source/arduino/scope.rst
+++ b/source/arduino/scope.rst
@@ -1,56 +1,59 @@
+.. highlight:: cpp
+
 .. _arduino-scope:
 
 Variable Scope
 ==============
 
-Variables in the C programming language, which Arduino uses, have a
-property called *scope*. This is in contrast to languages such as
-BASIC where every variable is a *global* variable.
-
-
-
-A global variable is one that can be *seen* by every function in a
-program. Local variables are only visible to the function in which
-they are declared. In the Arduino environment, any variable
-declared outside of a function (e.g. setup(), loop(), etc. ), is a
-global variable.
-
+Variables in the C++ programming language, which Maple uses (all of
+your sketches are C++ programs in disguise), have a property called
+*scope*. This is in contrast to languages such as BASIC where every
+variable is a *global* variable.
 
+A global variable is one that can be "seen" by every function in a
+program. Local variables are only usable within the function in which
+they are declared. In the :ref:`Maple IDE <ide>`, any variable
+declared outside of a function (like :ref:`setup() <arduino-setup>`,
+:ref:`loop() <arduino-loop>`, etc.), is a global variable.
 
 When programs start to get larger and more complex, local variables
-are a useful way to insure that only one function has access to its
-own variables. This prevents programming errors when one function
+are a useful way to ensure that a function has exclusive access to its
+own variables.  This prevents programming errors when one function
 inadvertently modifies variables used by another function.
 
+It is also sometimes useful to declare and initialize a variable
+inside a :ref:`for <arduino-for>` loop. This creates a variable that
+can only be accessed from inside the loop body.
 
-
-It is also sometimes handy to declare and initialize a variable
-inside a *for* loop. This creates a variable that can only be
-accessed from inside the for-loop brackets.
-
-
+Scope in C++ is actually a fairly complex topic.  More information is
+available in the `C++ programming Wikibook
+<http://en.wikibooks.org/wiki/C%2B%2B_Programming/Programming_Languages/C%2B%2B/Code/Statements/Scope>`_.
 
 Example:
 --------
 
 ::
 
-    int gPWMval;  // any function will see this variable
-    
-    void setup()
-    {
+    int globalVar;  // any function will see this variable
+
+    void setup() {
       // ...
     }
-    
-    void loop()
-    {
+
+    void loop() {
       int i;    // "i" is only "visible" inside of "loop"
       float f;  // "f" is only "visible" inside of "loop"
       // ...
-    
+
       for (int j = 0; j <100; j++){
-      // variable j can only be accessed inside the for-loop brackets
+          // variable j can only be accessed inside the for-loop brackets
+          i = j * j;
       }
-    
+      i = globalVar; // globalVar can be accessed from anywhere, including loop()
     }
 
+See Also
+--------
+
+- `C++ programming Wikibook <http://en.wikibooks.org/wiki/C%2B%2B_Programming/Programming_Languages/C%2B%2B/Code/Statements/Scope>`_.
+- Wikipedia article on `scope <http://en.wikipedia.org/wiki/Scope_%28programming%29>`_
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