ジェネレータ(コルーチン・ファイバー・イテレータ)を色々な言語で

JavaScript,C♯,VB,HSP,Python,D言語,Lua,Scheme(Gauche),Tcl,Rubyで
同様の処理を書き比べしました。

hoges=["hoge","fuga","piyo"]
foos=["foo","bar","baz"]

で定義されるリストを交互で順番に読み出します。

hoge
foo
fuga
bar
piyo
baz

JavaScript

"use strict";

function* gen(){
	const hoges=["hoge","fuga","piyo"];
	const foos=["foo","bar","baz"];
	for(var i=0,hlen=hoges.length;i<hlen;i=0|i+1){
		yield hoges[i];
		yield foos[i];
	}
}

(function(){
	const g=gen();
	for(var i=0;i<6;i=0|i+1){
		console.log(g.next().value);
	}
})();

C♯

using System;
using System.Collections.Generic;

class Program{
	static IEnumerator<string> gen(){
		string[] hoges={"hoge","fuga","piyo"};
		string[] foos={"foo","bar","baz"};
		for(var i=0;i<hoges.Length;i++){
			yield return hoges[i];
			yield return foos[i];
		}
	}

	static void Main(){
		var g=gen();
		for(var i=0;i<6;i++){
			g.MoveNext();
			Console.WriteLine(g.Current);
		}
	}
}

VB

Option Strict On
Option Infer On
Imports System
Imports System.Collections.Generic

Module Program
	Iterator Function gen() As IEnumerator(Of String)
		Dim hoges As String()={"hoge","fuga","piyo"}
		Dim foos As String()={"foo","bar","baz"}

		For i=0i To hoges.Length-1
			Yield hoges(i)
			Yield foos(i)
		Next
	End Function

	Sub Main()
		Dim g=gen()
		For i=1i To 6
			g.MoveNext()
			Console.WriteLine(g.Current)
		Next
	End Sub
End Module

HSP

# runtime "hsp3cl"
# cmpopt varinit 1

# module __gen value,_yield
	#define global gen(%1) dimtype %1,5 :newmod %1,__gen
	#modinit
		hoges="hoge","fuga","piyo"
		foos="foo","bar","baz"
		dimtype _yield,1
		newlab _yield,1: return
		for i,0,length(hoges)
			value=hoges(i)
			newlab _yield,1: return
			value=foos(i)
			newlab _yield,1: return
		next
		value=""
	return

	#modcfunc genNextValue
		gosub _yield: return value
# global

# module Program
	#deffunc main
		gen g
		repeat 6
			mes genNextValue(g)
		loop
	return
# global
main

Python

def gen():
	hoges=["hoge","fuga","piyo"]
	foos=["foo","bar","baz"]
	for i in range(0,len(hoges)):
		yield hoges[i]
		yield foos[i]

def main():
	g=gen()
	for i in range(0,6):
		print(next(g))

if __name__=="__main__":main()

D言語

import std.stdio;
import std.concurrency;

Generator!string gen(){
	return new Generator!string((){
	    yield("");
		auto hoges=["hoge","fuga","piyo"];
		auto foos=["foo","bar","baz"];
		for(auto i=0;i<hoges.length;i++){
			yield(hoges[i]);
			yield(foos[i]);
		}
    });
}

void main(){
	auto g=gen();
	for(int i=0;i<6;i++){
		g.popFront();
		writeln(g.front);
	}
}

Lua

function gen()
	return coroutine.create(function()
		local hoges={"hoge","fuga","piyo"}
		local foos={"foo","bar","baz"}
		for i=1,#hoges do
			coroutine.yield(hoges[i])
			coroutine.yield(foos[i])
		end
	end)
end

(function()
	local g=gen()
	for i=1,6 do
		print(({coroutine.resume(g)})[2])
	end
end)()

Scheme(Gauche)

(use gauche.generator)

(define gen
	(^()(generate(^(yield)
		(let loop(
			(hoges '("hoge" "fuga" "piyo"))
			(foos '("foo" "bar" "baz")
		))
			(yield (car hoges))
			(yield (car foos))
			(loop (cdr hoges) (cdr foos))
		)
	)))
)

((lambda()
	(let((g (gen)))
	(let loop ((i 0))
		(when (< i 6)
			(print (g))
			(loop (+ i 1))
		)
	))
))

Tcl

proc gen {g} {
	proc gen {} {
		set hoges {"hoge" "fuge" "piyo"}
		set foos {"foo" "bar" "baz"}
		yield [info coroutine]
		for {set i 0} {$i<[llength $hoges]} {incr i} {
			yield [lindex $hoges $i]
			yield [lindex $foos $i]
		}
	}
	coroutine $g gen
}

apply {{} {
	gen g
	for {set i 0} {$i<6} {incr i} {
		puts [g]
	}
}}

Ruby

def gen()
	Fiber.new do
		hoges=["hoge","fuga","piyo"]
		foos=["foo","bar","baz"]
		for i in 0..hoges.length-1 do
			Fiber.yield(hoges[i])
			Fiber.yield(foos[i])
		end
	end
end

lambda do
	g=gen()
	for i in 1..6 do
		puts g.resume
	end
end.[]