diff --git a/streamjs/streamjs.d.ts b/streamjs/streamjs.d.ts
index 8ac67d583..464a449ca 100644
--- a/streamjs/streamjs.d.ts
+++ b/streamjs/streamjs.d.ts
@@ -8,36 +8,36 @@ declare class Stream<T> {
 	static make <T> (elems: T[]): Stream<T>;
 	static range (startInclusive: number, endExclusive: number): Stream<number>;
 	static rangeClosed (startInclusive: number, endInclusive: number): Stream<number>;
-	static generate <T> (supplier: () => T): Stream<T>;
+	static generate <T> (supplier: Stream.Supplier<T>): Stream<T>;
 	// static empty<T>(): Stream<T>;
 	
-	anyMatch(predicate: Stream.Predicate): boolean;
+	anyMatch(predicate: Stream.Predicate<T>): boolean;
 	anyMatch(regexp: RegExp): boolean;
-	allMatch(predicate: (elem: T) => boolean): boolean;
+	allMatch(predicate: Stream.Predicate<T>): boolean;
 	allMatch(regexp: RegExp): boolean;
 	average(): number;
 	avg(): number;
 	collect(collector: Stream.Collector<T>): T;
 	count(): number;
 	distinct(): Stream<T>;
-	dropWhile(predicate: (elem: T) => boolean): Stream<T>;
+	dropWhile(predicate: Stream.Predicate<T>): Stream<T>;
 	dropWhile(regexp: RegExp): Stream<string>;
-	filter(predicate: (T) => boolean): Stream<T>;
+	filter(predicate: Stream.Predicate<T>): Stream<T>;
 	findAny(): Stream.Optional<T>;
 	findFirst(): Stream.Optional<T>;
-	forEach(consumer: (elem: T) => void): void;
+	forEach(consumer: Stream.Consumer<T>): void;
 	
-	groupBy(mapper: (elem: T) => string): Stream.GroupingResult<T>;
-	groupingBy(mapper: (elem: T) => string): Stream.GroupingResult<T>;
-	indexBy(keyMapper: (elem: T) => string, mergeFunction?: (elem1: T, elem2: T) => T): T[];
-	map <U> (mapper: (T) => U): Stream<U>;
+	groupBy(mapper: Stream.Function<T, string>): Stream.GroupingResult<T>;
+	groupingBy(mapper: Stream.Function<T, string>): Stream.GroupingResult<T>;
+	indexBy(keyMapper: Stream.Function<T, string>, mergeFunction?: Stream.Accumulator<T>): T[];
+	map <U> (mapper: Stream.Function<T, U>): Stream<U>;
 	max(): Stream.Optional<T>;
-	max(comparator: (e1: T, e2: T) => number): Stream.Optional<T>;
+	max(comparator: Stream.Comparator<T>): Stream.Optional<T>;
 	min(): Stream.Optional<T>;
-	min(comparator: (elem1: T, elem2: T) => number): Stream.Optional<T>;
+	min(comparator: Stream.Comparator<T>): Stream.Optional<T>;
 	noneMatch(predicate: (elem: T) => boolean): boolean;
 	noneMatch(regexp: RegExp): boolean;
-	flatMap <U> (mapper: (T) => U[]): Stream<U>;
+	flatMap <U> (mapper: Stream.Function<T, U[]>): Stream<U>;
 	iterator(): Stream.Iterator<T>;
 	joining(): string;
 	joining(delimiter: string): string;
@@ -46,56 +46,76 @@ declare class Stream<T> {
 	join(delimiter: string): string;
 	join(options: Stream.JoinOptions): string;
 	limit(limit: number): Stream<T>;
-	partitioningBy(predicate: (elem: T) => boolean): T[][];
-	partitionBy(predicate: (elem: T) => boolean): T[][];
+	partitioningBy(predicate: Stream.Predicate<T>): T[][];
+	partitionBy(predicate: Stream.Predicate<T>): T[][];
 	partitioningBy(regexp: RegExp): T[][];
 	partitionBy(regexp: RegExp): T[][];
 	partitioningBy(size: number): T[][];
 	partitionBy(size: number): T[][];
-	peek(consumer: (elem: T) => void ): Stream<T>;
-	reduce(identity: T, accumulator: (e1: T, e2: T) => T): T;
-	reduce(accumulator: (e1: T, e2: T) => T): Stream.Optional<T>;
+	peek(consumer: Stream.Consumer<T>): Stream<T>;
+	reduce(identity: T, accumulator: Stream.Accumulator<T>): T;
+	reduce(accumulator: Stream.Accumulator<T>): Stream.Optional<T>;
 	reverse(): Stream<T>;
 	size(): number;
 	sorted(): Stream<T>;
-	sorted(comparator: (e1: T, e2: T) => number): Stream<T>;
+	sorted(comparator: Stream.Comparator<T>): Stream<T>;
 	sort(): Stream<T>;
-	sort(comparator: (e1: T, e2: T) => number): Stream<T>;
+	sort(comparator: Stream.Comparator<T>): Stream<T>;
 	shuffle(): Stream<T>;
 	skip(n: number): Stream<T>;
 	slice(begin, end): Stream<T>;
 	sum(): T;
-	takeWhile(predicate: (elem: T) => boolean): Stream<T>;
+	takeWhile(predicate: Stream.Predicate<T>): Stream<T>;
 	takeWhile(regexp: RegExp): Stream<string>;
 	toArray(): T[];
-	toMap(keyMapper: (elem: T) => string, mergeFunction?: (elem1: T, elem2: T) => T): T[];
+	toMap(keyMapper: Stream.Function<T, string>, mergeFunction?: Stream.Accumulator<T>): T[];
 }
 
 declare module Stream {
 
-	export interface Predicate<T> {
-		(elem: T): boolean;
+	export interface Accumulator<T> {
+		(e1: T, e2: T): T;
+	}
+	
+	export interface Collector<T> {
+		supplier: Supplier<T>;
+		accumulator: Stream.Accumulator<T>;
+		finisher: Function<T, T>;
 	}
 
+	export interface Comparator<T> {
+		(e1: T, e2: T): number
+	}
+	
+	export interface Consumer<T> {
+		(elem: T): void;
+	}
+
+	export interface Function<T, U> {
+		(elem: T): U;
+	}
+	
+	export interface GroupingResult<T> {
+		[index: string]: T
+	}
+	
 	export interface Iterator<T> {
 		next(): T;
 		done: boolean;
 	}
-
+	
 	export interface JoinOptions {
 		prefix: string;
 		delimiter: string;
 		suffix: string;
 	}
 
-	export interface GroupingResult<T> {
-		[index: string]: T
+	export interface Predicate<T> {
+		(elem: T): boolean;
 	}
-
-	export interface Collector<T> {
-		supplier(): T;
-		accumulator(e1: T, e2: T): T;
-		finisher(result: T): T
+	
+	export interface Supplier<T> {
+		(): T
 	}
 
 	export class Optional<T> {
@@ -110,7 +130,7 @@ declare module Stream {
 		get(): T;
 		ifPresent(consumer: (elem: T) => void): void;
 		orElse(other: T): T;
-		orElseGet(supplier: () => T): T;
+		orElseGet(supplier: Stream.Supplier<T>): T;
 		orElseThrow(error: any): T;
 	}
 }