Add type declarations

package.json

@@ -3,6 +3,7 @@
   "version": "2.0.1",
   "description": "Normalizes JSON according to schema for Flux application",
   "main": "lib/index.js",
+  "typings": "typings.d.ts",
   "repository": {
     "type": "git",
     "url": "https://github.com/gaearon/normalizr.git"

typings.d.ts

@@ -0,0 +1,70 @@
+export type SchemaOptions = {
+  idAttribute?: string | Function;
+}
+
+export type IterableSchemaOptions = {
+  schemaAttribute?: string | Function;
+}
+
+export type UnionSchemaOptions = {
+  schemaAttribute: string | Function;
+}
+
+export type NormalizeOptions = {
+  assignEntity?: Function;
+  mergeIntoEntity?: Function;
+}
+
+export type NormalizeInput = Object | Array<Object>;
+
+export type NormalizeOutput = {
+  result: any;
+  entities?: any;
+}
+
+export class Schema {
+  constructor (key: string, options?: SchemaOptions);
+
+  define(schema: SchemaMap): void;
+  getKey(): string;
+  getIdAttribute(): string;
+}
+
+export class IterableSchema {
+  constructor (schema: SchemaValue, options?: IterableSchemaOptions);
+
+  getItemSchema(): SchemaValue;
+}
+
+export class UnionSchema {
+  constructor (schema: SchemaValue, options: UnionSchemaOptions);
+
+  getItemSchema(): SchemaValue;
+}
+
+export type SchemaValue = Schema | IterableSchema | UnionSchema | SchemaMap;
+
+export type SchemaMap = {
+  [key: string]: SchemaValue;
+}
+
+export function arrayOf(
+  schema: SchemaValue,
+  options?: IterableSchemaOptions
+): IterableSchema;
+
+export function valuesOf(
+  schema: SchemaValue,
+  options?: IterableSchemaOptions
+): IterableSchema;
+
+export function unionOf(
+  schema: SchemaValue,
+  options?: UnionSchemaOptions
+): UnionSchema;
+
+export function normalize(
+  input: NormalizeInput,
+  schema: SchemaValue,
+  options?: NormalizeOptions
+): NormalizeOutput;