mirror of
https://github.com/golang/go
synced 2024-10-03 06:21:21 -06:00
exp/iterable: delete
Package iterable has outlived its utility. It is an interesting demonstration, but it encourages people to use iteration over channels where simple iteration over array indices or a linked list would be cheaper, simpler, and have fewer races. R=dsymonds, r CC=golang-dev https://golang.org/cl/2436041
This commit is contained in:
Russ Cox
parent
f75129894c
commit
e6ecf9765a
@ -63,7 +63,6 @@ DIRS=\
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exp/draw\
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exp/draw/x11\
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exp/eval\
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exp/iterable\
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expvar\
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flag\
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fmt\
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@ -180,19 +180,6 @@ func (l *List) MoveToBack(e *Element) {
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// Len returns the number of elements in the list.
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func (l *List) Len() int { return l.len }
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func (l *List) iterate(c chan<- interface{}) {
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for e := l.front; e != nil; e = e.next {
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c <- e.Value
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}
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close(c)
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}
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func (l *List) Iter() <-chan interface{} {
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c := make(chan interface{})
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go l.iterate(c)
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return c
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}
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// PushBackList inserts each element of ol at the back of the list.
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func (l *List) PushBackList(ol *List) {
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last := ol.Back()
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@ -116,8 +116,8 @@ func TestList(t *testing.T) {
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// Check standard iteration.
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sum := 0
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for e := range l.Iter() {
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if i, ok := e.(int); ok {
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for e := l.Front(); e != nil; e = e.Next() {
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if i, ok := e.Value.(int); ok {
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sum += i
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}
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}
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@ -141,7 +141,8 @@ func checkList(t *testing.T, l *List, es []interface{}) {
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return
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}
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i := 0
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for le := range l.Iter() {
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for e := l.Front(); e != nil; e = e.Next() {
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le := e.Value.(int)
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if le != es[i] {
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t.Errorf("elt #%d has value=%v, want %v", i, le, es[i])
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}
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@ -1,12 +0,0 @@
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# Copyright 2009 The Go Authors. All rights reserved.
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# Use of this source code is governed by a BSD-style
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# license that can be found in the LICENSE file.
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include ../../../Make.inc
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TARG=exp/iterable
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GOFILES=\
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array.go\
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iterable.go\
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include ../../../Make.pkg
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@ -1,72 +0,0 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package iterable
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// This file implements the Iterable interface on some primitive types.
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type ByteArray []byte
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func (a ByteArray) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go func() {
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for _, e := range a {
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ch <- e
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}
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close(ch)
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}()
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return ch
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}
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type IntArray []int
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func (a IntArray) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go func() {
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for _, e := range a {
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ch <- e
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}
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close(ch)
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}()
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return ch
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}
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type FloatArray []float
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func (a FloatArray) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go func() {
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for _, e := range a {
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ch <- e
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}
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close(ch)
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}()
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return ch
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}
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type StringArray []string
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func (a StringArray) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go func() {
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for _, e := range a {
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ch <- e
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}
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close(ch)
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}()
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return ch
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}
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type UintArray []uint
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func (a UintArray) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go func() {
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for _, e := range a {
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ch <- e
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}
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close(ch)
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}()
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return ch
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}
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@ -1,344 +0,0 @@
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// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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// The iterable package provides several traversal and searching methods.
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// It can be used on anything that satisfies the Iterable interface,
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// including vector, though certain functions, such as Map, can also be used on
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// something that would produce an infinite amount of data.
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package iterable
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import (
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"container/list"
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"container/vector"
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)
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type Iterable interface {
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// Iter should return a fresh channel each time it is called.
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Iter() <-chan interface{}
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}
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func not(f func(interface{}) bool) func(interface{}) bool {
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return func(e interface{}) bool { return !f(e) }
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}
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// All tests whether f is true for every element of iter.
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func All(iter Iterable, f func(interface{}) bool) bool {
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for e := range iter.Iter() {
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if !f(e) {
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return false
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}
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}
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return true
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}
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// Any tests whether f is true for at least one element of iter.
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func Any(iter Iterable, f func(interface{}) bool) bool {
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return !All(iter, not(f))
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}
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// Data returns a slice containing the elements of iter.
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func Data(iter Iterable) []interface{} {
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var v vector.Vector
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for e := range iter.Iter() {
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v.Push(e)
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}
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return v
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}
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// filteredIterable is a struct that implements Iterable with each element
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// passed through a filter.
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type filteredIterable struct {
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it Iterable
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f func(interface{}) bool
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}
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func (f *filteredIterable) iterate(out chan<- interface{}) {
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for e := range f.it.Iter() {
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if f.f(e) {
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out <- e
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}
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}
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close(out)
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}
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func (f *filteredIterable) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go f.iterate(ch)
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return ch
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}
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// Filter returns an Iterable that returns the elements of iter that satisfy f.
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func Filter(iter Iterable, f func(interface{}) bool) Iterable {
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return &filteredIterable{iter, f}
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}
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// Find returns the first element of iter that satisfies f.
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// Returns nil if no such element is found.
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func Find(iter Iterable, f func(interface{}) bool) interface{} {
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for e := range Filter(iter, f).Iter() {
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return e
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}
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return nil
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}
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// Injector is a type representing a function that takes two arguments,
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// an accumulated value and an element, and returns the next accumulated value.
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// See the Inject function.
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type Injector func(interface{}, interface{}) interface{}
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// Inject combines the elements of iter by repeatedly calling f with an
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// accumulated value and each element in order. The starting accumulated value
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// is initial, and after each call the accumulated value is set to the return
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// value of f. For instance, to compute a sum:
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// var arr IntArray = []int{ 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 };
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// sum := iterable.Inject(arr, 0,
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// func(ax interface {}, x interface {}) interface {} {
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// return ax.(int) + x.(int) }).(int)
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func Inject(iter Iterable, initial interface{}, f Injector) interface{} {
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acc := initial
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for e := range iter.Iter() {
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acc = f(acc, e)
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}
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return acc
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}
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// mappedIterable is a helper struct that implements Iterable, returned by Map.
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type mappedIterable struct {
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it Iterable
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f func(interface{}) interface{}
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}
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func (m *mappedIterable) iterate(out chan<- interface{}) {
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for e := range m.it.Iter() {
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out <- m.f(e)
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}
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close(out)
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}
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func (m *mappedIterable) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go m.iterate(ch)
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return ch
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}
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// Map returns an Iterable that returns the result of applying f to each
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// element of iter.
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func Map(iter Iterable, f func(interface{}) interface{}) Iterable {
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return &mappedIterable{iter, f}
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}
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// Partition(iter, f) returns Filter(iter, f) and Filter(iter, !f).
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func Partition(iter Iterable, f func(interface{}) bool) (Iterable, Iterable) {
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return Filter(iter, f), Filter(iter, not(f))
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}
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// A Func is a function that, when called, sends the
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// iterable values on a channel.
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type Func func(chan<- interface{})
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// Iter creates and returns a new channel; it starts a
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// goroutine running f to send values to the channel.
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func (f Func) Iter() <-chan interface{} {
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ch := make(chan interface{})
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go f(ch)
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return ch
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}
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// Take returns an Iterable that contains the first n elements of iter.
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func Take(iter Iterable, n int) Iterable { return Slice(iter, 0, n) }
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// TakeWhile returns an Iterable that contains elements from iter while f is true.
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func TakeWhile(iter Iterable, f func(interface{}) bool) Iterable {
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return Func(func(ch chan<- interface{}) {
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for v := range iter.Iter() {
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if !f(v) {
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break
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}
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ch <- v
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}
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close(ch)
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})
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}
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// Drop returns an Iterable that returns each element of iter after the first n elements.
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func Drop(iter Iterable, n int) Iterable {
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return Func(func(ch chan<- interface{}) {
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m := n
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for v := range iter.Iter() {
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if m > 0 {
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m--
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continue
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}
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ch <- v
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}
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close(ch)
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})
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}
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// DropWhile returns an Iterable that returns each element of iter after the initial sequence for which f returns true.
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func DropWhile(iter Iterable, f func(interface{}) bool) Iterable {
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return Func(func(ch chan<- interface{}) {
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drop := true
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for v := range iter.Iter() {
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if drop {
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if f(v) {
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continue
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}
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drop = false
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}
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ch <- v
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}
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close(ch)
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})
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}
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// Cycle repeats the values of iter in order infinitely.
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func Cycle(iter Iterable) Iterable {
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return Func(func(ch chan<- interface{}) {
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for {
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for v := range iter.Iter() {
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ch <- v
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}
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}
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})
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}
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// Chain returns an Iterable that concatenates all values from the specified Iterables.
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func Chain(args []Iterable) Iterable {
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return Func(func(ch chan<- interface{}) {
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for _, e := range args {
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for v := range e.Iter() {
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ch <- v
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}
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}
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close(ch)
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})
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}
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// Zip returns an Iterable of []interface{} consisting of the next element from
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// each input Iterable. The length of the returned Iterable is the minimum of
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// the lengths of the input Iterables.
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func Zip(args []Iterable) Iterable {
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return Func(func(ch chan<- interface{}) {
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defer close(ch)
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if len(args) == 0 {
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return
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}
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iters := make([]<-chan interface{}, len(args))
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for i := 0; i < len(iters); i++ {
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iters[i] = args[i].Iter()
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}
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for {
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out := make([]interface{}, len(args))
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for i, v := range iters {
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out[i] = <-v
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if closed(v) {
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return
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}
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}
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ch <- out
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}
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})
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}
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// ZipWith returns an Iterable containing the result of executing f using arguments read from a and b.
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func ZipWith2(f func(c, d interface{}) interface{}, a, b Iterable) Iterable {
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return Map(Zip([]Iterable{a, b}), func(a1 interface{}) interface{} {
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arr := a1.([]interface{})
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return f(arr[0], arr[1])
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})
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}
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// ZipWith returns an Iterable containing the result of executing f using arguments read from a, b and c.
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func ZipWith3(f func(d, e, f interface{}) interface{}, a, b, c Iterable) Iterable {
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return Map(Zip([]Iterable{a, b, c}), func(a1 interface{}) interface{} {
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arr := a1.([]interface{})
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return f(arr[0], arr[1], arr[2])
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})
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}
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// Slice returns an Iterable that contains the elements from iter
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// with indexes in [start, stop).
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func Slice(iter Iterable, start, stop int) Iterable {
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return Func(func(ch chan<- interface{}) {
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defer close(ch)
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i := 0
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for v := range iter.Iter() {
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switch {
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case i >= stop:
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return
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case i >= start:
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ch <- v
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}
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i++
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}
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})
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}
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// Repeat generates an infinite stream of v.
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func Repeat(v interface{}) Iterable {
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return Func(func(ch chan<- interface{}) {
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for {
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ch <- v
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}
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})
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}
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// RepeatTimes generates a stream of n copies of v.
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func RepeatTimes(v interface{}, n int) Iterable {
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return Func(func(ch chan<- interface{}) {
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for i := 0; i < n; i++ {
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ch <- v
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}
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close(ch)
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})
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}
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// Group is the type for elements returned by the GroupBy function.
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type Group struct {
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Key interface{} // key value for matching items
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Vals Iterable // Iterable for receiving values in the group
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}
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// Key defines the interface required by the GroupBy function.
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type Grouper interface {
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// Return the key for the given value
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Key(interface{}) interface{}
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|
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// Compute equality for the given keys
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Equal(a, b interface{}) bool
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}
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// GroupBy combines sequences of logically identical values from iter using k
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// to generate a key to compare values. Each value emitted by the returned
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// Iterable is of type Group, which contains the key used for matching the
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// values for the group, and an Iterable for retrieving all the values in the
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// group.
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func GroupBy(iter Iterable, k Grouper) Iterable {
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return Func(func(ch chan<- interface{}) {
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var curkey interface{}
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var lst *list.List
|
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// Basic strategy is to read one group at a time into a list prior to emitting the Group value
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for v := range iter.Iter() {
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kv := k.Key(v)
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if lst == nil || !k.Equal(curkey, kv) {
|
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if lst != nil {
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ch <- Group{curkey, lst}
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}
|
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lst = list.New()
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curkey = kv
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}
|
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lst.PushBack(v)
|
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}
|
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if lst != nil {
|
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ch <- Group{curkey, lst}
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}
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close(ch)
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})
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}
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|
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// Unique removes duplicate values which occur consecutively using id to compute keys.
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func Unique(iter Iterable, id Grouper) Iterable {
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return Map(GroupBy(iter, id), func(v interface{}) interface{} { return v.(Group).Key })
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}
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@ -1,391 +0,0 @@
|
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// Copyright 2009 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
package iterable
|
||||
|
||||
import (
|
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"container/vector"
|
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"testing"
|
||||
)
|
||||
|
||||
func TestArrayTypes(t *testing.T) {
|
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// Test that conversion works correctly.
|
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bytes := ByteArray([]byte{1, 2, 3})
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if x := Data(bytes)[1].(byte); x != 2 {
|
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t.Error("Data(bytes)[1].(byte) = %v, want 2", x)
|
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}
|
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uints := UintArray([]uint{1, 2, 3})
|
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if x := Data(uints)[1].(uint); x != 2 {
|
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t.Error("Data(uints)[1].(uint) = %v, want 2", x)
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}
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ints := IntArray([]int{1, 2, 3})
|
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if x := Data(ints)[2].(int); x != 3 {
|
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t.Error("Data(ints)[2].(int) = %v, want 3", x)
|
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}
|
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floats := FloatArray([]float{1, 2, 3})
|
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if x := Data(floats)[0].(float); x != 1 {
|
||||
t.Error("Data(floats)[0].(float) = %v, want 1", x)
|
||||
}
|
||||
strings := StringArray([]string{"a", "b", "c"})
|
||||
if x := Data(strings)[1].(string); x != "b" {
|
||||
t.Error(`Data(strings)[1].(string) = %q, want "b"`, x)
|
||||
}
|
||||
}
|
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|
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var (
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||||
oneToFive = IntArray{1, 2, 3, 4, 5}
|
||||
sixToTen = IntArray{6, 7, 8, 9, 10}
|
||||
elevenToTwenty = IntArray{11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
|
||||
)
|
||||
|
||||
func isNegative(n interface{}) bool { return n.(int) < 0 }
|
||||
func isPositive(n interface{}) bool { return n.(int) > 0 }
|
||||
func isAbove3(n interface{}) bool { return n.(int) > 3 }
|
||||
func isEven(n interface{}) bool { return n.(int)%2 == 0 }
|
||||
func doubler(n interface{}) interface{} { return n.(int) * 2 }
|
||||
func addOne(n interface{}) interface{} { return n.(int) + 1 }
|
||||
func adder(acc interface{}, n interface{}) interface{} {
|
||||
return acc.(int) + n.(int)
|
||||
}
|
||||
|
||||
// A stream of the natural numbers: 0, 1, 2, 3, ...
|
||||
type integerStream struct{}
|
||||
|
||||
func (i integerStream) Iter() <-chan interface{} {
|
||||
ch := make(chan interface{})
|
||||
go func() {
|
||||
for i := 0; ; i++ {
|
||||
ch <- i
|
||||
}
|
||||
}()
|
||||
return ch
|
||||
}
|
||||
|
||||
func TestAll(t *testing.T) {
|
||||
if !All(oneToFive, isPositive) {
|
||||
t.Error("All(oneToFive, isPositive) == false")
|
||||
}
|
||||
if All(oneToFive, isAbove3) {
|
||||
t.Error("All(oneToFive, isAbove3) == true")
|
||||
}
|
||||
}
|
||||
|
||||
func TestAny(t *testing.T) {
|
||||
if Any(oneToFive, isNegative) {
|
||||
t.Error("Any(oneToFive, isNegative) == true")
|
||||
}
|
||||
if !Any(oneToFive, isEven) {
|
||||
t.Error("Any(oneToFive, isEven) == false")
|
||||
}
|
||||
}
|
||||
|
||||
func assertArraysAreEqual(t *testing.T, res []interface{}, expected []int) {
|
||||
if len(res) != len(expected) {
|
||||
t.Errorf("len(res) = %v, want %v", len(res), len(expected))
|
||||
goto missing
|
||||
}
|
||||
for i := range res {
|
||||
if v := res[i].(int); v != expected[i] {
|
||||
t.Errorf("res[%v] = %v, want %v", i, v, expected[i])
|
||||
goto missing
|
||||
}
|
||||
}
|
||||
return
|
||||
missing:
|
||||
t.Errorf("res = %v\nwant %v", res, expected)
|
||||
}
|
||||
|
||||
func TestFilter(t *testing.T) {
|
||||
ints := integerStream{}
|
||||
moreInts := Filter(ints, isAbove3).Iter()
|
||||
res := make([]interface{}, 3)
|
||||
for i := 0; i < 3; i++ {
|
||||
res[i] = <-moreInts
|
||||
}
|
||||
assertArraysAreEqual(t, res, []int{4, 5, 6})
|
||||
}
|
||||
|
||||
func TestFind(t *testing.T) {
|
||||
ints := integerStream{}
|
||||
first := Find(ints, isAbove3)
|
||||
if first.(int) != 4 {
|
||||
t.Errorf("Find(ints, isAbove3) = %v, want 4", first)
|
||||
}
|
||||
}
|
||||
|
||||
func TestInject(t *testing.T) {
|
||||
res := Inject(oneToFive, 0, adder)
|
||||
if res.(int) != 15 {
|
||||
t.Errorf("Inject(oneToFive, 0, adder) = %v, want 15", res)
|
||||
}
|
||||
}
|
||||
|
||||
func TestMap(t *testing.T) {
|
||||
res := Data(Map(Map(oneToFive, doubler), addOne))
|
||||
assertArraysAreEqual(t, res, []int{3, 5, 7, 9, 11})
|
||||
}
|
||||
|
||||
func TestPartition(t *testing.T) {
|
||||
ti, fi := Partition(oneToFive, isEven)
|
||||
assertArraysAreEqual(t, Data(ti), []int{2, 4})
|
||||
assertArraysAreEqual(t, Data(fi), []int{1, 3, 5})
|
||||
}
|
||||
|
||||
func TestTake(t *testing.T) {
|
||||
res := Take(oneToFive, 2)
|
||||
assertArraysAreEqual(t, Data(res), []int{1, 2})
|
||||
assertArraysAreEqual(t, Data(res), []int{1, 2}) // second test to ensure that .Iter() returns a new channel
|
||||
|
||||
// take none
|
||||
res = Take(oneToFive, 0)
|
||||
assertArraysAreEqual(t, Data(res), []int{})
|
||||
|
||||
// try to take more than available
|
||||
res = Take(oneToFive, 20)
|
||||
assertArraysAreEqual(t, Data(res), oneToFive)
|
||||
}
|
||||
|
||||
func TestTakeWhile(t *testing.T) {
|
||||
// take some
|
||||
res := TakeWhile(oneToFive, func(v interface{}) bool { return v.(int) <= 3 })
|
||||
assertArraysAreEqual(t, Data(res), []int{1, 2, 3})
|
||||
assertArraysAreEqual(t, Data(res), []int{1, 2, 3}) // second test to ensure that .Iter() returns a new channel
|
||||
|
||||
// take none
|
||||
res = TakeWhile(oneToFive, func(v interface{}) bool { return v.(int) > 3000 })
|
||||
assertArraysAreEqual(t, Data(res), []int{})
|
||||
|
||||
// take all
|
||||
res = TakeWhile(oneToFive, func(v interface{}) bool { return v.(int) < 3000 })
|
||||
assertArraysAreEqual(t, Data(res), oneToFive)
|
||||
}
|
||||
|
||||
func TestDrop(t *testing.T) {
|
||||
// drop none
|
||||
res := Drop(oneToFive, 0)
|
||||
assertArraysAreEqual(t, Data(res), oneToFive)
|
||||
assertArraysAreEqual(t, Data(res), oneToFive) // second test to ensure that .Iter() returns a new channel
|
||||
|
||||
// drop some
|
||||
res = Drop(oneToFive, 2)
|
||||
assertArraysAreEqual(t, Data(res), []int{3, 4, 5})
|
||||
assertArraysAreEqual(t, Data(res), []int{3, 4, 5}) // second test to ensure that .Iter() returns a new channel
|
||||
|
||||
// drop more than available
|
||||
res = Drop(oneToFive, 88)
|
||||
assertArraysAreEqual(t, Data(res), []int{})
|
||||
}
|
||||
|
||||
func TestDropWhile(t *testing.T) {
|
||||
// drop some
|
||||
res := DropWhile(oneToFive, func(v interface{}) bool { return v.(int) < 3 })
|
||||
assertArraysAreEqual(t, Data(res), []int{3, 4, 5})
|
||||
assertArraysAreEqual(t, Data(res), []int{3, 4, 5}) // second test to ensure that .Iter() returns a new channel
|
||||
|
||||
// test case where all elements are dropped
|
||||
res = DropWhile(oneToFive, func(v interface{}) bool { return v.(int) < 100 })
|
||||
assertArraysAreEqual(t, Data(res), []int{})
|
||||
|
||||
// test case where none are dropped
|
||||
res = DropWhile(oneToFive, func(v interface{}) bool { return v.(int) > 1000 })
|
||||
assertArraysAreEqual(t, Data(res), oneToFive)
|
||||
}
|
||||
|
||||
func TestCycle(t *testing.T) {
|
||||
res := Cycle(oneToFive)
|
||||
exp := []int{1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 1, 2, 3, 4}
|
||||
|
||||
// read the first nineteen values from the iterable
|
||||
out := make([]interface{}, 19)
|
||||
for i, it := 0, res.Iter(); i < 19; i++ {
|
||||
out[i] = <-it
|
||||
}
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
|
||||
res2 := Cycle(sixToTen)
|
||||
exp2 := []int{6, 7, 8, 9, 10, 6, 7, 8, 9, 10, 6, 7, 8, 9, 10, 6, 7, 8, 9}
|
||||
for i, it := 0, res2.Iter(); i < 19; i++ {
|
||||
out[i] = <-it
|
||||
}
|
||||
assertArraysAreEqual(t, out, exp2)
|
||||
|
||||
// ensure first iterator was not harmed
|
||||
for i, it := 0, res.Iter(); i < 19; i++ {
|
||||
out[i] = <-it
|
||||
}
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
}
|
||||
|
||||
func TestChain(t *testing.T) {
|
||||
|
||||
exp := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
|
||||
res := Chain([]Iterable{oneToFive, sixToTen, elevenToTwenty})
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
|
||||
// reusing the same iterator should produce the same result again
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
|
||||
// test short read from Chain
|
||||
i := 0
|
||||
out := make([]interface{}, 4)
|
||||
for v := range res.Iter() {
|
||||
out[i] = v
|
||||
i++
|
||||
if i == len(out) {
|
||||
break
|
||||
}
|
||||
}
|
||||
assertArraysAreEqual(t, out, exp[0:4])
|
||||
|
||||
// test zero length array
|
||||
res = Chain([]Iterable{})
|
||||
assertArraysAreEqual(t, Data(res), []int{})
|
||||
}
|
||||
|
||||
func TestZipWith(t *testing.T) {
|
||||
exp := []int{7, 9, 11, 13, 15}
|
||||
|
||||
// f with 2 args and 1 return value
|
||||
f := func(a, b interface{}) interface{} { return a.(int) + b.(int) }
|
||||
res := ZipWith2(f, oneToFive, sixToTen)
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
|
||||
// test again to make sure returns new iter each time
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
|
||||
// test a function with 3 args
|
||||
f2 := func(a, b, c interface{}) interface{} { return a.(int) + b.(int) + c.(int) }
|
||||
res = ZipWith3(f2, oneToFive, sixToTen, oneToFive)
|
||||
exp = []int{8, 11, 14, 17, 20}
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
|
||||
// test a function with multiple values returned
|
||||
f3 := func(a, b interface{}) interface{} { return ([]interface{}{a.(int) + 1, b.(int) + 1}) }
|
||||
res = ZipWith2(f3, oneToFive, sixToTen)
|
||||
|
||||
exp2 := [][]int{[]int{2, 7}, []int{3, 8}, []int{4, 9}, []int{5, 10}, []int{6, 11}}
|
||||
i := 0
|
||||
for v := range res.Iter() {
|
||||
out := v.([]interface{})
|
||||
assertArraysAreEqual(t, out, exp2[i])
|
||||
i++
|
||||
}
|
||||
|
||||
// test different length iterators--should stop after shortest is exhausted
|
||||
res = ZipWith2(f, elevenToTwenty, oneToFive)
|
||||
exp = []int{12, 14, 16, 18, 20}
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
}
|
||||
|
||||
func TestSlice(t *testing.T) {
|
||||
out := Data(Slice(elevenToTwenty, 2, 6))
|
||||
exp := []int{13, 14, 15, 16}
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
|
||||
// entire iterable
|
||||
out = Data(Slice(elevenToTwenty, 0, len(elevenToTwenty)))
|
||||
exp = []int{11, 12, 13, 14, 15, 16, 17, 18, 19, 20}
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
|
||||
// empty slice at offset 0
|
||||
exp = []int{}
|
||||
out = Data(Slice(elevenToTwenty, 0, 0))
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
|
||||
// slice upper bound exceeds length of iterable
|
||||
exp = []int{1, 2, 3, 4, 5}
|
||||
out = Data(Slice(oneToFive, 0, 88))
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
|
||||
// slice upper bounce is lower than lower bound
|
||||
exp = []int{}
|
||||
out = Data(Slice(oneToFive, 93, 4))
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
|
||||
// slice lower bound is greater than len of iterable
|
||||
exp = []int{}
|
||||
out = Data(Slice(oneToFive, 93, 108))
|
||||
assertArraysAreEqual(t, out, exp)
|
||||
}
|
||||
|
||||
func TestRepeat(t *testing.T) {
|
||||
res := Repeat(42)
|
||||
i := 0
|
||||
for v := range res.Iter() {
|
||||
if v.(int) != 42 {
|
||||
t.Fatal("Repeat returned the wrong value")
|
||||
}
|
||||
if i == 9 {
|
||||
break
|
||||
}
|
||||
i++
|
||||
}
|
||||
}
|
||||
|
||||
func TestRepeatTimes(t *testing.T) {
|
||||
res := RepeatTimes(84, 9)
|
||||
exp := []int{84, 84, 84, 84, 84, 84, 84, 84, 84}
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
assertArraysAreEqual(t, Data(res), exp) // second time to ensure new iter is returned
|
||||
|
||||
// 0 repeat
|
||||
res = RepeatTimes(7, 0)
|
||||
exp = []int{}
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
|
||||
// negative repeat
|
||||
res = RepeatTimes(7, -3)
|
||||
exp = []int{}
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
}
|
||||
|
||||
// a type that implements Key for ints
|
||||
type intkey struct{}
|
||||
|
||||
func (v intkey) Key(a interface{}) interface{} {
|
||||
return a
|
||||
}
|
||||
func (v intkey) Equal(a, b interface{}) bool { return a.(int) == b.(int) }
|
||||
|
||||
func TestGroupBy(t *testing.T) {
|
||||
in := IntArray{1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5}
|
||||
exp := [][]int{[]int{1}, []int{2, 2}, []int{3, 3, 3}, []int{4, 4, 4, 4}, []int{5, 5, 5, 5, 5}}
|
||||
i := 0
|
||||
for x := range GroupBy(in, intkey{}).Iter() {
|
||||
gr := x.(Group)
|
||||
if gr.Key.(int) != i+1 {
|
||||
t.Fatal("group key wrong; expected", i+1, "but got", gr.Key.(int))
|
||||
}
|
||||
vals := Data(gr.Vals)
|
||||
assertArraysAreEqual(t, vals, exp[i])
|
||||
i++
|
||||
}
|
||||
if i != 5 {
|
||||
t.Fatal("did not return expected number of groups")
|
||||
}
|
||||
|
||||
// test 0 length Iterable
|
||||
for _ = range GroupBy(IntArray([]int{}), &intkey{}).Iter() {
|
||||
t.Fatal("iterator should be empty")
|
||||
}
|
||||
|
||||
// test case with only uniques
|
||||
var out vector.Vector
|
||||
for x := range GroupBy(elevenToTwenty, intkey{}).Iter() {
|
||||
out.Push(x.(Group).Key)
|
||||
}
|
||||
assertArraysAreEqual(t, out, elevenToTwenty)
|
||||
}
|
||||
|
||||
func TestUnique(t *testing.T) {
|
||||
in := IntArray([]int{1, 2, 2, 3, 3, 3, 4, 4, 4, 4, 5, 5, 5, 5, 5})
|
||||
exp := []int{1, 2, 3, 4, 5}
|
||||
res := Unique(in, intkey{})
|
||||
assertArraysAreEqual(t, Data(res), exp)
|
||||
assertArraysAreEqual(t, Data(res), exp) // second time to ensure new iter is returned
|
||||
|
||||
// test case with only uniques
|
||||
res = Unique(elevenToTwenty, intkey{})
|
||||
assertArraysAreEqual(t, Data(res), elevenToTwenty)
|
||||
}
|
||||
Loading…
Reference in New Issue
Block a user