indent. implement map and filter

index.js

@@ -1,6 +1,10 @@
 var Fs = require("fs"),
     R = function (p) {
-        return JSON.parse(Fs.readFileSync(p, 'utf-8'));
+        var content = Fs.readFileSync(p, 'utf-8');
+        if (content.charAt(content.length - 1) !== '\n') {
+            throw new Error("file at " + p + " did not end with a newline character");
+        }
+        return JSON.parse(content);
     },
     P = module.exports.peers = {
         AS: {
@@ -90,6 +94,42 @@ var Fs = require("fs"),
                 },
             },
         },
+    },
+    map = module.exports.map = function (f) {
+        var L = [];
+
+        // t/f is the object a credential
+        var isCred = function (k) {
+            // creds end in .k
+            return /\.k/.test(k);
+            return true;
         };
 
-//console.log(JSON.stringify(P, null, 2));
+        var walk = function (o, p, f) {
+            // walk the tree of objects
+
+            if (typeof(o) === 'object') {
+                // for each key in o, walk the key
+                Object.keys(o).forEach(function (k) {
+                    var path = p.slice(0).concat(k);
+
+
+                    if (isCred(k)) {
+                        //console.log(o[k]);
+                        L.push(f(o[k], path));
+                    }
+                    walk(o[k], path, f);
+                });
+            }
+        };
+
+        walk(P, [], f);
+        return L;
+    },
+    filter = module.exports.filter = function (f) {
+        var L = [];
+        map(function (x, p) {
+            if (f(x,p)) { L.push(x); }
+        });
+        return L;
+    };