diff --git a/sys/apis/map.lua b/sys/apis/map.lua
new file mode 100644
index 0000000..4fc3bc8
--- /dev/null
+++ b/sys/apis/map.lua
@@ -0,0 +1,37 @@
+-- convience functions for tables with key/value pairs
+local Util = require('util')
+
+local Map = { }
+
+function Map.removeMatches(t, values)
+	local function matchAll(entry)
+		for k, v in pairs(values) do
+			if entry[k] ~= v then
+				return
+			end
+		end
+		return true
+	end
+
+	for k,v in pairs(t) do
+		if matchAll(v) then
+			t[k] = nil
+		end
+	end
+end
+
+-- remove table entries if passed function returns false
+function Map.prune(t, fn)
+	for _,k in pairs(Util.keys(t)) do
+		local v = t[k]
+		if type(v) == 'table' then
+			t[k] = Util.prune(v, fn)
+		end
+		if not fn(t[k]) then
+			t[k] = nil
+		end
+	end
+	return t
+end
+
+return Map
diff --git a/sys/apis/ui/components/Form.lua b/sys/apis/ui/components/Form.lua
index 43b3557..6db3085 100644
--- a/sys/apis/ui/components/Form.lua
+++ b/sys/apis/ui/components/Form.lua
@@ -122,10 +122,7 @@ function UI.Form:save()
 	end
 	for _,child in pairs(self.children) do
 		if child.formKey then
-			if (child.pruneEmpty and type(child.value) == 'string' and #child.value == 0) or
-				 (child.pruneEmpty and type(child.value) == 'boolean' and not child.value) then
-				self.values[child.formKey] = nil
-			elseif child.validate == 'numeric' then
+			if child.validate == 'numeric' then
 				self.values[child.formKey] = tonumber(child.value)
 			else
 				self.values[child.formKey] = child.value
diff --git a/sys/apis/util.lua b/sys/apis/util.lua
index 658f875..8b3d26b 100644
--- a/sys/apis/util.lua
+++ b/sys/apis/util.lua
@@ -187,20 +187,6 @@ function Util.deepMerge(obj, args)
 	end
 end
 
--- remove table entries if passed function returns false
-function Util.prune(t, fn)
-	for _,k in pairs(Util.keys(t)) do
-		local v = t[k]
-		if type(v) == 'table' then
-			t[k] = Util.prune(v, fn)
-		end
-		if not fn(t[k]) then
-			t[k] = nil
-		end
-	end
-	return t
-end
-
 function Util.transpose(t)
 	local tt = { }
 	for k,v in pairs(t) do