easy-loop

* 쉬운 동기식 반복처리
* 선택적 병렬처리

iteration function

1) Method
: 모두 같은 동작이며 편리한 메소드를 호출하세요.

var loop = require('easy-loop');
loop(arg, arg [, arg, arg]) == loop.for() == loop.while()

2) Arguments
(1) Array or Object or function or iteration number - require
(2) process function - require
(3) concurrency number - option (default : 1)
(4) callback function - option (default : nothing)

* TIP : arg2 와 arg3 의 인자값은 순서 변경 가능(arg3 and arg3 can be swap)

series or parallel or waterfall function

1) Method
var loop = require('easy-loop');
//series('function array or object' [, concurrency] [, callback]) -> 'concurrency' default 1
loop.series([
function(callback){
var result = "success";
callback(null, result);
},
...], function(err, results){
//err : undefined
//results : ["success"...]
});

loop.parallel({
one : function(callback){
var result = "success";
callback(null, result);
},
...}, function(err, results){
//err : undefined
//results : {"one":"success"...}
});

loop.waterfall([
function(callback){
var arg1 = 1;
callback(null, arg1);
},
function(arg, callback){
//console.log(arg) => 1
var arg1 = 2;
callback(null, arg, arg1);
},
function(arg1, arg2, callback){
//console.log(arg1, arg2) => 1, 2
var arg1 = 3;
callback(null, arg1);
}], function(err, results){
//err : undefined
//console.log(results) => 3
});

2) Arguments
(1) Array or Object (waterfall only Array) - require
(2) callback function - option

Examples

var loop = require('easy-loop');

var arr = [1,2,3,4,5];
console.log("Case1 Start => Array and 3 arguments");
console.log("Start : Now Second : ", new Date().getSeconds());
loop(arr, function(i, value, next){
setTimeout(function(){
console.log(i, "=>", value, " , Date : ", new Date().getSeconds());
next(); //require
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case 1 result");
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case1 End => Array");

/* 결과(Result) - 5초 소요(run time : 5 second)
Case1 Start => Array and 3 arguments
Start : Now Second : 54
Case1 End => Array
0 '=>' 1 ' , Date : ' 55
1 '=>' 2 ' , Date : ' 56
2 '=>' 3 ' , Date : ' 57
3 '=>' 4 ' , Date : ' 58
4 '=>' 5 ' , Date : ' 59
err : undefined
Case 1 result
Result : Now Second : 59
*/




var arr = [1,2,3,4,5];
console.log("Case2 Start => Array and 2 arguments");
loop.for(arr, function(i, value, next){
setTimeout(function(){
console.log(i, "=>", value);
next();
}, 1000);
});
console.log("Case2 End => Array and 2 arguments");

/* 결과(Result) - 5초 소요(run time : 5 second)
Case2 Start => Array and 2 arguments
Case2 End => Array and 2 arguments
0 '=>' 1
1 '=>' 2
2 '=>' 3
3 '=>' 4
4 '=>' 5
*/




var arr = [1,2,3,4,5];
console.log("Case3 Start => Array and error(or break) and 3 arguments");
loop(arr, function(i, value, next){
setTimeout(function(){
console.log(i, "=>", value);
if(i === 2) next("error or break");
else next();
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case 3 result");
});
console.log("Case3 End => Array and error(or break)");

/* 결과(Result) - 3초 소요(run time : 3 second)
Case3 Start => Array and error(or break) and 3 arguments
Case3 End => Array and error(or break)
0 '=>' 1
1 '=>' 2
2 '=>' 3
err : error or break
Case 3 result
*/




var obj = {a:1,b:2,c:3,d:4,e:5};
console.log("Case4 Start => Object and 3 arguments");
loop(obj, function(key, value, next){
setTimeout(function(){
console.log(key, "=>", value);
next();
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case 4 result");
});
console.log("Case4 End => Object");

/* 결과(Result) - 5초 소요(run time : 5 second)
Case4 Start => Object and 3 arguments
Case4 End => Object
a => 1
b => 2
c => 3
d => 4
e => 5
err : undefined
Case 4 result
*/





var arr = []; // or {}
console.log("Case5 Start => Empty Array and 3 arguments");
loop(arr, function(i, value, next){
setTimeout(function(){
console.log(i, "=>", value);
next();
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case5 result");
});
console.log("Case5 End => Empty Array");

/* 결과(Result) - 0초 소요(run time : 0 second)
Case5 Start => Empty Array and 3 arguments
err : undefined
Case5 result
Case5 End => Empty Array
*/





var arr = [1,2,3,4,5];
console.log("Case6 Start => concurrency and 4 arguments");
console.log("Start : Now Second : ", new Date().getSeconds());
loop(arr, function(i, value, next){
setTimeout(function(){
console.log(i, "=>", value, " , Date : ", new Date().getSeconds());
next();
}, 1000);
}, 3, function(err){
console.log("err : ", err);
console.log("Case 6 result");
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case6 End => concurrency");

/*
*Tip : arguments(arr, function, concurrency, callback) == arguments(arr, concurrency, function, callback)
결과(Result) - 2초 소요(run time : 2 second)
Case6 Start => concurrency and 4 arguments
Start : Now Second : 3
Case6 End => concurrency
0 '=>' 1 ' , Date : ' 4
1 '=>' 2 ' , Date : ' 4
2 '=>' 3 ' , Date : ' 4
3 '=>' 4 ' , Date : ' 5
4 '=>' 5 ' , Date : ' 5
err : undefined
Case 6 result
Result : Now Second : 5
*/






var num = 0;
console.log("Case7 Start => while and 3 arguments");
console.log("Start : Now Second : ", new Date().getSeconds());
loop.while(function(){
return num < 5;
}, function(next){
setTimeout(function(){
console.log("Date : ", new Date().getSeconds());
num++;
next();
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case 7 result");
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case7 End");

/*
결과(Result) - 5초 소요(run time : 5 second)
Case7 Start => while and 3 arguments
Start : Now Second : 20
Case7 End
Date : 21
Date : 22
Date : 23
Date : 24
Date : 25
err : undefined
Case 7 result
Result : Now Second : 25
*/




var num = 0;
console.log("Case8 Start => while and 3 arguments and break(or error)");
console.log("Start : Now Second : ", new Date().getSeconds());
loop.while(function(){
return num < 5;
}, function(next){
setTimeout(function(){
console.log("Date : ", new Date().getSeconds());
num++;
next(num === 1 ? true : false);
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case 8 result");
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case8 End");

/*
Case8 Start => while and 3 arguments and break(or error)
Start : Now Second : 21
Case8 End
Date : 22
err : true
Case 8 result
Result : Now Second : 22
*/



console.log("Case9 Start => When only know the number of iterations. 2 arguments or 3 arguments(concurrency) and break possible");
console.log("Start : Now Second : ", new Date().getSeconds());
var loopCount = 5;
loop(loopCount, function(i, next){
setTimeout(function(){
console.log(i, "Date : ", new Date().getSeconds());
next(); // break => next(err);
}, 1000);
}, function(err){
console.log("err : ", err);
console.log("Case 9 result");
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case9 End");

/*
Case9 Start => When only know the number of iterations. 2 arguments or 3 arguments(concurrency) and break possible
Start : Now Second : 23
Case9 End
0 'Date : ' 24
1 'Date : ' 25
2 'Date : ' 26
3 'Date : ' 27
4 'Date : ' 28
err : undefined
Case 9 result
Result : Now Second : 28
*/




console.log("Case10 Start => When only know the number of iterations. break possible");
console.log("Start : Now Second : ", new Date().getSeconds());
var handle = loop.create(10, function(err){
console.log("err : ", err);
console.log("Case 10 result");
console.log("Result : Now Second : ", new Date().getSeconds());
});
for(var i=0; i<10; i++)
{
setTimeout(function(){
console.log("Date : ", new Date().getSeconds());
handle.next(); // break => handle.next(err);
}, 1000);
}
console.log("Case10 End");

/*
Case10 Start => When only know the number of iterations
Start : Now Second : 20
Case10 End
Date : 21
Date : 21
Date : 21
Date : 21
Date : 21
Date : 21
Date : 21
Date : 21
Date : 21
Date : 21
err : undefined
Case 10 result
Result : Now Second : 21
*/




console.log("Case11 Start => Array. Like as 'async.series' of async module. If the error is when to stop.");
console.log("Start : Now Second : ", new Date().getSeconds());
var arr = [
function(callback){
console.log("start series");
callback();
},
function(callback){
setTimeout(function(){
console.log(100);
callback(null, 100);
}, 1000);
}, function(callback){
setTimeout(function(){
console.log(200);
callback(null, 200);
}, 1000);
}
];
loop.series(arr, function(err, results){
console.log("err : ", err);
console.log("results : ", JSON.stringify(results));
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case11 End");

/*
Case11 Start => Array. Like as 'async.series' of async module. If the error is when to stop.
Start : Now Second : 50
start series
Case11 End
100
200
err : undefined
results : [null,100,200]
Result : Now Second : 52
*/




console.log("Case12 Start => Object. Like as 'async.series' of async module. If the error is when to stop.");
console.log("Start : Now Second : ", new Date().getSeconds());
var obj = {
one : function(callback){
console.log("start series");
callback();
},
two : function(callback){
setTimeout(function(){
console.log(100);
callback(null, 100);
}, 1000);
},
three : function(callback){
setTimeout(function(){
console.log(200);
callback(null, 200);
}, 1000);
}
};
loop.series(obj, function(err, results){
console.log("err : ", err);
console.log("results : ", JSON.stringify(results));
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case12 End");

/*
Case12 Start => Object. Like as 'async.series' of async module. If the error is when to stop.
Start : Now Second : 38
start series
Case12 End
100
200
err : undefined
results : {"one":null,"two":100,"three":200}
Result : Now Second : 40
*/





console.log("Case13 Start => Array. Like as 'async.parallel' of async module. If the error is when to stop.");
console.log("Start : Now Second : ", new Date().getSeconds());
var arr = [
function(callback){
console.log("start parallel");
callback();
},
function(callback){
setTimeout(function(){
console.log(100);
callback(null, 100);
}, 500);
}, function(callback){
setTimeout(function(){
console.log(200);
callback(null, 200);
}, 500);
}
];
loop.parallel(arr, function(err, results){
console.log("err : ", err);
console.log("results : ", JSON.stringify(results));
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case13 End");

/*
Case13 Start => Array. Like as 'async.parallel' of async module. If the error is when to stop.
Start : Now Second : 55
start parallel
Case13 End
100
200
err : undefined
results : [null,100,200]
Result : Now Second : 55
*/




console.log("Case14 Start => Object. Like as 'async.parallel' of async module. If the error is when to stop.");
console.log("Start : Now Second : ", new Date().getSeconds());
var obj = {
one : function(callback){
console.log("start parallel");
callback();
},
two : function(callback){
setTimeout(function(){
console.log(100);
callback(null, 100);
}, 500);
},
three : function(callback){
setTimeout(function(){
console.log(200);
callback(null, 200);
}, 500);
}
};
loop.parallel(obj, function(err, results){
console.log("err : ", err);
console.log("results : ", JSON.stringify(results));
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case14 End");

/*
Case14 Start => Object. Like as 'async.parallel' of async module. If the error is when to stop.
Start : Now Second : 59
start parallel
Case14 End
100
200
err : undefined
results : {"one":null,"two":100,"three":200}
Result : Now Second : 59
*/




console.log("Case15 Start => Array(or Object). Like as 'async.series'. But sub functions run parallel.");
console.log("Start : Now Second : ", new Date().getSeconds());
var obj = [
[
function(cb){
setTimeout(function(){console.log(new Date().getSeconds(), "sub1");
cb(null, "sub1");}, 1000)
},
function(cb){
setTimeout(function(){console.log(new Date().getSeconds(), "sub2");
cb(null, "sub2");}, 1000)
}
],
function(callback){
setTimeout(function(){
console.log(new Date().getSeconds(), 100);
callback(null, 100);
}, 1000);
},
function(callback){
setTimeout(function(){
console.log(new Date().getSeconds(), 200);
callback(null, 200);
}, 1000);
}
];
loop.series(obj, function(err, results){
console.log("err : ", err);
console.log("results : ", JSON.stringify(results));
console.log("Result : Now Second : ", new Date().getSeconds());
});
console.log("Case15 End");

/*
Case15 Start => Array(or Object). Like as 'async.series'. But sub functions run
parallel.
Start : Now Second : 59
Case15 End
0 'sub1'
0 'sub2'
1 100
2 200
err : undefined
results : [["sub1","sub2"],100,200]
Result : Now Second : 2
*/