add function compare

docs/finding_data.markdown

@@ -16,10 +16,25 @@ The search object can take a few forms depending on what you want to find:
 {eyes: {is: [1, 2]}} // eyes is 1 OR 2
 {friends: {includes: 'kevin'}}  //friends array includes kevin
 
+// Run a function to compare objects
+{name: {func: function(field, objects){
+  return objects.filter(function(entry){
+    return entry[field] == "david"
+  })
+}}}
+
 results = db.where({name: 'david'}); // where name is david
 results.length // 1
 results[0].height // 105
 
+results = db.where({name: {func: function(field, objects){
+  return objects.filter(function(entry){
+    return entry[field] == "david"
+  })
+}}})
+results.length // 1
+results[0].height // 105
+
 david = db.findOne({name: 'david'})
 david.height // 105
 

src/compares.coffee

@@ -39,3 +39,6 @@ module.exports =
   matches: (field, value, objects) ->
     objects.filter (entry) ->
       (value.test entry[field])
+
+  func: (field, value, objects) ->
+    value(field, objects)

tests/docs-tests.js

@@ -33,6 +33,14 @@ describe('Code Used in the Docs', function(){
     expect(results.length).to.equal(1);
     expect(results[0].height).to.equal(105);
 
+    results = db.where({name: {func: function(field, objects){
+      return objects.filter(function(entry){
+        return entry[field] == "david"
+      })
+    }}})
+    expect(results.length).to.equal(1);
+    expect(results[0].height).to.equal(105);
+
     david = db.findOne({name: 'david'})
     expect(david.height).to.equal(105)
 

tests/sodb-tests.coffee

@@ -103,6 +103,14 @@ for caching in [true, false]
         results = db.where({name: {matches: /kev/}})
         expect(results.length).to.equal 1
 
+      it 'should support a function', ->
+        results = db.where({name: {func: (field, objects) ->
+          objects.filter (entry) ->
+            (entry[field] == entry[field])
+        }})
+
+        expect(results.length).to.equal db.count()
+
     describe 'result manipulation', ->
       it 'should order by', ->
         ordered = db.order({name: {isnot: 'something new'}}, "age")