CouchDB – Where can I find more information about build in JavaScript functions like sum()?
When starting to work with CouchDB the lack of an indepth documentation can be a bit frustrating.
If you’re wondering where JavaScript methods like “sum” used in reduce functions are described, for example, you don’t find any detailed information in the CouchDB-Wiki.
What you can do is to have a look at:
COUCHDB_HOME/share/server
There are a number of javascript files.
They contain the method definitions you’re looking for.
For my version of CouchDB (0.10.1) there is a single .js file called main.js containing the sum function definition:
sum = function(values) {
var rv = 0;
for (var i in values) {
rv += values[i];
}
return rv;
}
In newer CouchDB versions such as 0.11.0 you’ll find multiple javascript files. Just have look at them.