Mercurial > urweb
diff demo/prose @ 648:3c6d535d3d8b
Increment demo
author | Adam Chlipala <adamc@hcoop.net> |
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date | Tue, 10 Mar 2009 13:57:09 -0400 |
parents | ae374df5ccbd |
children | 96ebc6bdb5a0 |
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--- a/demo/prose Tue Mar 10 13:46:45 2009 -0400 +++ b/demo/prose Tue Mar 10 13:57:09 2009 -0400 @@ -205,3 +205,7 @@ <p>The central data structure is the <tt>rlist</tt>, a list whose individual elements are sources, enabling fine-grained mutation. Every rlist is either nil or is a cons cell made up of a source for a string data element, another source to serve as a scratchpad for GUI-based edits to the data element, and a final source that stores the remainder of the list.</p> <p>The main program provides operations to append to a list and to edit the data stored at any cell of the list. Append is implemented by maintaining a source <tt>head</tt>, which points to the first list element; and a source <tt>tailP</tt>, which points to a <tt>source rlist</tt> where we should place the next appended node.</p> + +increment.urp + +<p>Here's an example where client-side code needs to run more code on the server. We maintain a (server-side) SQL sequence. When the user clicks a button, an AJAX request increments the remote sequence and gets the new value.</p>