lodown-seancsutton1/index.js

An npm functional programming library project

'use strict';

// YOU KNOW WHAT TO DO //

/**
 * each: Designed to loop over a collection, Array or Object, and applies the 
 * action Function to each value in the collection.
 * 
 * @param {Array or Object} collection: The collection over which to iterate.
 * @param {Function} action: The Function to be applied to each value in the 
 * collection
 */
function each(collection, action) {
    if(Array.isArray(collection)) {
        for(var i = 0; i < collection.length; i++) {
            action(collection[i], i, collection);
        }
    } else {
        for (var key in collection) {
            action(collection[key], key, collection);
        }
    }
}
module.exports.each = each;



  var identity = function(anything){
     return anything;
 }
 
 module.exports.identity = identity;
 
 
   var typeOf = function(anything){
                 if (Array.isArray(anything)){
                     return "array"
                 }else if (anything instanceof Date){
                     return "date"
                 }else if (anything === null){
                     return "null"
                 }else { return typeof anything 
             }
}
 
 module.exports.typeOf = typeOf;
 
 
 
 
  var first = function (collection, number ){
                var result = [];
            if (Array.isArray(collection) !== true){
                return result;
            } else if (number === undefined || typeof(number) !== "number"){
        return collection[0];
            }else if (collection.length < number){
            return collection
             }else if (typeof(number) === "number"){
        for (var i = 0 ; i <= number - 1 ; i++){
            result.push(collection[i]);
        }
    }return result;
}
 
 module.exports.first = first;
 
 
 var last = function (collection, number ){
                var result = [];
            if (Array.isArray(collection) !== true){
                return result;
            } else if (number === undefined || typeof(number) !== "number"){
        return collection[collection.length - 1];
            }else if (collection.length < number){
            return collection
             }else if (typeof(number) === "number"){
        for (var i = collection.length - number ; i <= collection.length - 1 ; i++){
            result.push(collection[i]);
        }
    }return result;
}
 
 module.exports.last = last;
 
 
 
 
  var indexOf = function(array, value){
        for(var i = 0 ; i < array.length; i ++){
            if(value === array[i]){
                return i;
            }
        } return - 1;
    };

 
 
  module.exports.indexOf = indexOf;
 
 
 
 
 
 
  var filter = function(collection, action ){
     var results = [];
    each(collection,function (value,index,collection){
        if (action(value,index,collection)){
            results.push(value);
        }
    })
    return results;
 }
 
 
 module.exports.filter = filter;
 
 
 
 
 
 
 
var reject = function(collection, action ){
     var results = [];
    each(collection,function (value,index,collection){
        if (!action(value,index,collection)){
            results.push(value);
        }
    })
    return results;
 }
 
 
 
 module.exports.reject = reject;
 
 
    var partition = function(collection, action){
                 var results = []
                 var passed = []
                 var rejected = [];
    each(collection,function (value,index,collection){
        if (!action(value,index,collection)){
            rejected.push(value);
        }else if (action(value,index,collection)){
            passed.push(value);
        }
    })
    results.push(passed);
    results.push(rejected)
    return results;
            }
 
 
 module.exports.partition = partition;
 
 
 var unique = function(array){
        var    results = [];
         each(array,function(value,index,collection){
            if (indexOf(results,value) === -1){
                results.push(value)
            }
         
         }) 
        return results;
}

 
 module.exports.unique = unique;
 
 
 
        map = function(collection, action){
               var results = [] 
               each(collection,function(value,index,collection){
                    results.push(action(value,index,collection))
                })
                return results;
 
 
 module.exports.map = map;
 
 
 
 
    pluck = function(collection, prop){
            var results = [];
            map(collection, function(value, index , collection){
                if (value[prop]){
                    results.push(value[prop])
                }
            })
            return results;
 
  module.exports.pluck = pluck;
  
  
  
  
  
  
  
  
   contains = function(collection, value){ return (indexOf(collection,value) > -1) ? true : false}
   
   module.exports.contains = contains;
   
   
   
   
   
                every = function(collection, action){
                    var results = true
                    each(collection, function(value, index ,collection){
                        if (action && !action(value,index,collection)){
                            results = false
                        }else if (!value){
                            results = false;
                        
                        }
                    })
                    return results;
                }

    module.exports.every = every;
    
    
    
    
    
    
    
        some = function(collection, action){
            var results = false;
                    each(collection, function(value, index ,collection){
                        if (action && !!action(value,index,collection)){
                             results = true
                        }else if (action === undefined){
                             results = !!value;
                        
                        }
                    })
                    return results
              
                }

            module.exports.some = some;
   
   
   
   
        reduce = function(collection, action, seed ){
            var results;
            if(seed === undefined){
              results = collection[0]   
              }else{
                  results = seed
              }
            each(collection, function(value, index, collection ){
              if (index === 0 && seed === undefined ){
                  return;
              }
              results = action(results,value,index)
                
            })
            return results;
        }

   module.exports.reduce = reduce;
   
   
   
   
   
   extend = function(...args){
      var object1 = args[0]
       each(args,function(value,index,args){
            for (var key in value){
          object1[key] = value[key];     
            }   
           })
             return object1;   
               }
   
   module.exports.extend = extend;