diff --git a/src/redux-arg/generateReducer.js b/src/redux-arg/generateReducer.js
index 1639d9f..2aa5f01 100644
--- a/src/redux-arg/generateReducer.js
+++ b/src/redux-arg/generateReducer.js
@@ -6,8 +6,6 @@ import { PROP_TYPES } from './constants';
 
 export function buildReducers(structure) {
 
-    //TODO - allow for building single primitive reducers
-
     const tmp = combineReducers(reduce(structure, (memo, propValue, propName) => {
         const { structure } = propValue();
 
diff --git a/src/redux-arg/reducers.js b/src/redux-arg/reducers.js
index e269930..b2feb98 100644
--- a/src/redux-arg/reducers.js
+++ b/src/redux-arg/reducers.js
@@ -10,61 +10,6 @@ import {
     compose
 } from 'ramda';
 
-type ObjectReducerAction = {
-    type: string,
-    payload?: Object,
-};
-type ObjectReducer = (Object) => (Object, ObjectReducerAction) => Object;
-
-type Primitive = string | number;
-type PrimitiveReducerAction = {
-    type: string,
-    payload?: string | number,
-};
-type PrimitiveReducer = (Primitive) => (Primitive, PrimitiveReducerAction) => Primitive;
-
-type ArrayReducerAction = {
-    type: string,
-    payload?: Array,
-    index?: number,
-};
-type ArrayReducer = (Array) => (Array, ArrayReducerAction) => Array;
-
-const REDUCER_FUNCTIONS = {
-    objectReducer(reducerStructureDescriptor): ObjectReducer {
-        const { structure } = reducerStructureDescriptor();
-        return (state = determineDefaults(reducerStructureDescriptor)(structure), { type, payload } = {}) => {
-            switch (type) {
-                case 'BLARG!':
-                    return { state, ...reducerStructureDescriptor, ...payload };
-                default:
-                    return state;
-            }
-        }
-    },
-    primitiveReducer(reducerStructureDescriptor): PrimitiveReducer {
-        const { structure } = reducerStructureDescriptor();
-        return (state = determineDefaults(reducerStructureDescriptor)(structure), { type, payload } = {}) => {
-            switch(type) {
-                case 'BLARG2':
-                    return { state, ...structure, ...payload };
-                default:
-                    return state;
-            }
-        }
-    },
-    arrayReducer(reducerStructureDescriptor): ArrayReducer {
-        return (state = [], { type, payload } = {}) => {
-            switch(type) {
-                case 'BLARG3':
-                    return { state, ...reducerStructureDescriptor, ...payload };
-                default:
-                    return state;
-            }
-        }
-    }
-};
-
 const DEFAULTS_FUNCTIONS = new Map([
     [PROP_TYPES._shape, objectDefaults],
     [PROP_TYPES._array, arrayDefaults],
diff --git a/src/redux-arg/reducers/arrayReducer.js b/src/redux-arg/reducers/arrayReducer.js
new file mode 100644
index 0000000..b5df5fc
--- /dev/null
+++ b/src/redux-arg/reducers/arrayReducer.js
@@ -0,0 +1,21 @@
+//@flow
+import type { ReducerStructure } from '../structure';
+
+export type ArrayReducerAction = {
+    type: string,
+    payload?: any[],
+    index?: number,
+};
+export type ArrayReducerFactory = (structure: Object) => ArrayReducer;
+export type ArrayReducer = (state: any[], action: ArrayReducerAction) => any[];
+
+export function arrayReducer<ArrayReducerFactory>(reducerStructureDescriptor: ReducerStructure) {
+    return(state: any[] = [], { type, payload = []}: ArrayReducerAction = {}): any[] => {
+        switch(type) {
+            case 'BLARG3':
+                return [ state, ...payload ];
+            default:
+                return state;
+        }
+    }
+}
diff --git a/src/redux-arg/reducers/objectReducer.js b/src/redux-arg/reducers/objectReducer.js
new file mode 100644
index 0000000..f090448
--- /dev/null
+++ b/src/redux-arg/reducers/objectReducer.js
@@ -0,0 +1,19 @@
+//@flow
+type ObjectReducerAction = {
+    type: string,
+    payload?: Object,
+};
+type ObjectReducer = (Object) => (Object, ObjectReducerAction) => Object;
+
+export function objectReducer(reducerStructureDescriptor: Object): ObjectReducer {
+    const { structure } = reducerStructureDescriptor();
+    return (state = determineDefaults(reducerStructureDescriptor)(structure), { type, payload } = {}) => {
+        switch (type) {
+            case 'BLARG!':
+                return { state, ...reducerStructureDescriptor, ...payload };
+            default:
+                return state;
+        }
+    }
+}
+
diff --git a/src/redux-arg/reducers/primitiveReducer.js b/src/redux-arg/reducers/primitiveReducer.js
new file mode 100644
index 0000000..3d7de3e
--- /dev/null
+++ b/src/redux-arg/reducers/primitiveReducer.js
@@ -0,0 +1,19 @@
+//@flow
+type Primitive = string | number;
+type PrimitiveReducerAction = {
+    type: string,
+    payload?: string | number,
+};
+type PrimitiveReducer = (Primitive) => (Primitive, PrimitiveReducerAction) => Primitive;
+
+export function primitiveReducer(reducerStructureDescriptor): PrimitiveReducer {
+    const { structure } = reducerStructureDescriptor();
+    return (state = determineDefaults(reducerStructureDescriptor)(structure), { type, payload } = {}) => {
+        switch(type) {
+            case 'BLARG2':
+                return { state, ...structure, ...payload };
+            default:
+                return state;
+        }
+    }
+}
diff --git a/src/redux-arg/structure.js b/src/redux-arg/structure.js
new file mode 100644
index 0000000..a4a2794
--- /dev/null
+++ b/src/redux-arg/structure.js
@@ -0,0 +1,37 @@
+//@flow
+
+//==============================
+// Flow types
+//==============================
+export type ReducerStructure = {
+    [key: string]: StructureType
+}
+
+export type StructureType = (structure: ?ReducerStructure) => {
+    type: string,
+    structure: [StructureType | ReducerStructure]
+};
+
+//==============================
+// Structure
+//==============================
+export const PROP_TYPES = {
+    _string: '_string',
+    _number: '_number',
+    _reducer: '_reducer',
+    _shape: '_shape',
+    _array: '_array',
+};
+
+export const TYPE_DEFAULTS = new Map([
+    [PROP_TYPES._string, ''],
+    [PROP_TYPES._number, 0],
+]);
+
+export const Types = {
+    string: () => ({ type: PROP_TYPES._string, structure: PROP_TYPES._string }),
+    number: () => ({ type: PROP_TYPES._number, structure: PROP_TYPES._number }),
+    arrayOf: (structure: ReducerStructure) => () => ({ type: PROP_TYPES._array, structure }),
+    reducer: (structure: ReducerStructure) => () => ({ type: PROP_TYPES._reducer, structure }),
+    shape: (structure: ReducerStructure) => () => ({ type: PROP_TYPES._shape, structure}),
+};