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  • addAttributeToFilter and OR condition in Magento's Collection

    - by ÉricP
    Hi, I'd like to select products depending on several criteria from different attribute. I know how to user $collection->addAttributeToFilter('someattribute', array('like' => '%')); But I'd like to use several attribute for OR condition. Like: $collection->addAttributeToFilter('someattribute', array('like' => 'value'));` OR $collection->addAttributeToFilter('otherattribute', array('like' => 'value'));` To get products which either 'someattribute' OR 'otherattribute' set to 'value' Is it possible?

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  • How to delete duplicate/aggregate rows faster in a file using Java (no DB)

    - by S. Singh
    I have a 2GB big text file, it has 5 columns delimited by tab. A row will be called duplicate only if 4 out of 5 columns matches. Right now, I am doing dduping by first loading each coloumn in separate List , then iterating through lists, deleting the duplicate rows as it encountered and aggregating. The problem: it is taking more than 20 hours to process one file. I have 25 such files to process. Can anyone please share their experience, how they would go about doing such dduping? This dduping will be a throw away code. So, I was looking for some quick/dirty solution, to get job done as soon as possible. Here is my pseudo code (roughly) Iterate over the rows i=current_row_no. Iterate over the row no. i+1 to last_row if(col1 matches //find duplicate && col2 matches && col3 matches && col4 matches) { col5List.set(i,get col5); //aggregate } Duplicate example A and B will be duplicate A=(1,1,1,1,1), B=(1,1,1,1,2), C=(2,1,1,1,1) and output would be A=(1,1,1,1,1+2) C=(2,1,1,1,1) [notice that B has been kicked out]

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  • Initial capacity of collection types, i.e. Dictionary, List

    - by Neil N
    Certain collection types in .Net have an optional "Initial Capacity" constructor param. i.e. Dictionary<string, string> something = new Dictionary<string,string>(20); List<string> anything = new List<string>(50); I can't seem to find what the default initial capacity is for these objects on MSDN. If I know I will only be storing 12 or so items in a dictionary, doesn't it make sense to set the initial capacity to something like 20? My reasoning is, assuming the capacity grows like it does for a StringBuiler, which doubles each time the capacity is hit, and each re-allocation is costly, why not pre-set the size to something you know will hold your data, with some extra room just in case? If the initial capacity is 100, and I know I will only need a dozen or so, it seems as though the rest of that allocated RAM is allocated for nothing. Please spare me the "premature optimization" speil for the O(n^n)th time. I know it won't make my apps any faster or save any meaningful amount of memory, this is mostly out of curiosity.

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  • how to make accessor for Dictionary in a way that returned Dictionary cannot be changed C# / 2.0

    - by matti
    I thought of solution below because the collection is very very small. But what if it was big? private Dictionary<string, OfTable> _folderData = new Dictionary<string, OfTable>(); public Dictionary<string, OfTable> FolderData { get { return new Dictionary<string,OfTable>(_folderData); } } With List you can make: public class MyClass { private List<int> _items = new List<int>(); public IList<int> Items { get { return _items.AsReadOnly(); } } } That would be nice! Thanks in advance, Cheers & BR - Matti NOW WHEN I THINK THE OBJECTS IN COLLECTION ARE IN HEAP. SO MY SOLUTION DOES NOT PREVENT THE CALLER TO MODIFY THEM!!! CAUSE BOTH Dictionary s CONTAIN REFERENCES TO SAME OBJECT. DOES THIS APPLY TO List EXAMPLE ABOVE? class OfTable { private string _wTableName; private int _table; private List<int> _classes; private string _label; public OfTable() { _classes = new List<int>(); } public int Table { get { return _table; } set { _table = value; } } public List<int> Classes { get { return _classes; } set { _classes = value; } } public string Label { get { return _label; } set { _label = value; } } } so how to make this immutable??

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  • Undo/Redo using Memento: Stack, Queue or just LinkedList?

    - by serhio
    What is the best having when implementing Memento pattern (for Undo/Redo) in witch collection to Keep Mementos? Basically, I need this(c = change, u = undo, r = redo): 0 *c -1 0 *c -2 -1 0 *c -3 -2 -1 0 <u -2 -1 0 1 *c -3 -2 -1 0 Variants: LinkedList - possible in principle, maybe not optimized. Queue - not adapted for this task, IMO. Stack - not adapted for undo AND redo; Double Stack - maybe optimal, but can't control the undo maximum size.

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  • Populating and Using Dynamic Classes in C#/.NET 4.0

    - by Bob
    In our application we're considering using dynamically generated classes to hold a lot of our data. The reason for doing this is that we have customers with tables that have different structures. So you could have a customer table called "DOG" (just making this up) that contains the columns "DOGID", "DOGNAME", "DOGTYPE", etc. Customer #2 could have the same table "DOG" with the columns "DOGID", "DOG_FIRST_NAME", "DOG_LAST_NAME", "DOG_BREED", and so on. We can't create classes for these at compile time as the customer can change the table schema at any time. At the moment I have code that can generate a "DOG" class at run-time using reflection. What I'm trying to figure out is how to populate this class from a DataTable (or some other .NET mechanism) without extreme performance penalties. We have one table that contains ~20 columns and ~50k rows. Doing a foreach over all of the rows and columns to create the collection take about 1 minute, which is a little too long. Am I trying to come up with a solution that's too complex or am I on the right track? Has anyone else experienced a problem like this? Create dynamic classes was the solution that a developer at Microsoft proposed. If we can just populate this collection and use it efficiently I think it could work.

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  • Ordered List of Keyvaluepairs?

    - by boris callens
    Is there an collection in .net that allows the storing KeyValuePair<string, string> that keeps the order of inserting? OrderedDictionary looked promising, but seems to be rather lacking. Now I'm looking into IOrderedEnumerable, but I can't seem to find any implementation except for ISortedDictionary, but that's not what I want. No sorting needs to be done, just the order of inserting is important.

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  • Inheritance and type parameters of Traversable

    - by Jesper
    I'm studying the source code of the Scala 2.8 collection classes. I have questions about the hierarchy of scala.collection.Traversable. Look at the following declarations: package scala.collection trait Traversable[+A] extends TraversableLike[A, Traversable[A]] with GenericTraversableTemplate[A, Traversable] trait TraversableLike[+A, +Repr] extends HasNewBuilder[A, Repr] with TraversableOnce[A] package scala.collection.generic trait HasNewBuilder[+A, +Repr] trait GenericTraversableTemplate[+A, +CC[X] <: Traversable[X]] extends HasNewBuilder[A, CC[A] @uncheckedVariance] Question: Why does Traversable extend GenericTraversableTemplate with type parameters [A, Traversable] - why not [A, Traversable[A]]? I tried some experimenting with a small program with the same structure and got a strange error message when I tried to change it to Traversable[A]: error: Traversable[A] takes no type parameters, expected: one I guess that the use of the @uncheckedVariance annotation in GenericTraversableTemplate also has to do with this? (That seems like a kind of potentially unsafe hack to force things to work...). Question: When you look at the hierarchy, you see that Traversable inherits HasNewBuilder twice (once via TraversableLike and once via GenericTraversableTemplate), but with slightly different type parameters. How does this work exactly? Why don't the different type parameters cause an error?

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  • Scala 2.8.1 implicitly convert to java.util.List<java.util.Map<String, Object>>

    - by Ralph
    I have a Scala data structure created with the following: List(Map[String, Anyref]("a" -> someFoo, "b" -> someBar)) I would like to implicitly convert it (using scala.collection.JavaConversions or scala.collection.JavaConverters) to a java.util.List<java.util.Map<String, Object>> to be passed the a Java method that expects the latter. Is this possible? I have already created the following method that does it, but was wondering if it can be done automatically by the compiler? import scala.collection.JavaConversions._ def convertToJava(listOfMaps: List[Map[String, AnyRef]]): java.util.List[java.util.Map[String, Object]] = { asJavaList(listOfMaps.map(asJavaMap(_))) }

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  • How to print all values of Vector[]

    - by terence6
    I have a Vector[] of Object type that stores my data. How to print all it's objects ? The code: private static Vector<Object[]> vector = new Vector<Object[]>(); int event=0; for(int i=0; i<10; i++){ vector.add( this.addToObject(System.currentTimeMillis(), event , "String") ); event++; } private Object[] addToObject(long t, int i,String s ){ Object[] o = new Object[4]; o[3] = s; o[2] = i; o[1] = "00000"; o[0] = t; return o; } printing public static void main(String[]args){ main m = new Main(); for(int i=0; i< m.vector.size(); i++){ } } And I'd like to get sth like this : 1202393057117 1 OOOOO String 1202393057117 2 OOOOO String 1202393057118 3 OOOOO String 1202393057118 4 OOOOO String 1202393057118 5 OOOOO String

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  • Java 7 API design best practice - return Array or return Collection

    - by Shengjie
    I know this question has be asked before generic comes out. Array does win out a bit given Array enforces the return type, it's more type-safe. But now, with latest JDK 7, every time when I design this type of APIs: public String[] getElements(String type) vs public List<String> getElements(String type) I am always struggling to think of some good reasons to return A Collection over An Array or another way around. What's the best practice when it comes to the case of choosing String[] or List as the API's return type? Or it's courses for horses. I don't have a special case in my mind, I am more looking for a generic pros/cons comparison.

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  • Traversable => Java Iterator

    - by Andres
    I have a Traversable, and I want to make it into a Java Iterator. My problem is that I want everything to be lazily done. If I do .toIterator on the traversable, it eagerly produces the result, copies it into a List, and returns an iterator over the List. I'm sure I'm missing something simple here... Here is a small test case that shows what I mean: class Test extends Traversable[String] { def foreach[U](f : (String) => U) { f("1") f("2") f("3") throw new RuntimeException("Not lazy!") } } val a = new Test val iter = a.toIterator

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  • How to implement a collection (list, map?) of complicated strings in Java?

    - by Alex Cheng
    Hi all. I'm new here. Problem -- I have something like the following entries, 1000 of them: args1=msg args2=flow args3=content args4=depth args6=within ==> args5=content args1=msg args2=flow args3=content args4=depth args6=within args7=distance ==> args5=content args1=msg args2=flow args3=content args6=within ==> args5=content args1=msg args2=flow args3=content args6=within args7=distance ==> args5=content args1=msg args2=flow args3=flow ==> args4=flowbits args1=msg args2=flow args3=flow args5=content ==> args4=flowbits args1=msg args2=flow args3=flow args6=depth ==> args4=flowbits args1=msg args2=flow args3=flow args6=depth ==> args5=content args1=msg args2=flow args4=depth ==> args3=content args1=msg args2=flow args4=depth args5=content ==> args3=content args1=msg args2=flow args4=depth args5=content args6=within ==> args3=content args1=msg args2=flow args4=depth args5=content args6=within args7=distance ==> args3=content I'm doing some sort of suggestion method. Say, args1=msg args2=flow args3=flow == args4=flowbits If the sentence contains msg, flow, and another flow, then I should return the suggestion of flowbits. How can I go around doing it? I know I should scan (whenever a character is pressed on the textarea) a list or array for a match and return the result, but, 1000 entries, how should I implement it? I'm thinking of HashMap, but can I do something like this? <"msg,flow,flow","flowbits" Also, in a sentence the arguments might not be in order, so assuming that it's flow,flow,msg then I can't match anything in the HashMap as the key is "msg,flow,flow". What should I do in this case? Please help. Thanks a million!

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  • Accessing a struct collection property from within another collection

    - by paddyb
    I have a struct that I need to store in a collection. The struct has a property that returns a Dictionary. public struct Item { private IDictionary<string, string> values; public IDictionary<string, string> Values { get { return this.values ?? (this.values = new Dictionary<string, string>()); } } } public class ItemCollection : Collection<Item> {} When testing I've found that if I add the item to the collection and then try to access the dictionary the structs values property is never updated. var collection = new ItemCollection { new Item() }; // pre-loaded with an item collection[0].Values.Add("myKey", "myValue"); Trace.WriteLine(collection[0].Values["myKey"]); // KeyNotFoundException here However if I load up the item first and then add it to a collection the values field is maintained. var collection = new ItemCollection(); var item = new Item(); item.Values.Add("myKey", "myValue"); collection.Add(item); Trace.WriteLine(collection[0].Values["myKey"]); // ok I've already decided that a struct is the wrong option for this type, and when using a class the issue doesn't occur, but I'm curious what's different between the two methods. Can anybody explain what's happening?

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  • Why is TreeSet<T> an internal type in .NET?

    - by Justin Niessner
    So, I was just digging around Reflector trying to find the implementation details of HashSet (out of sheer curiosity based on the answer to another question here) and noticed the following: internal class TreeSet<T> : ICollection<T>, IEnumerable<T>, ICollection, IEnumerable, ISerializable, IDeserializationCallback Without looking too deep into the details, it looks like a Self-Balancing Binary Search Tree. My question is, is there anybody out there with the insight as to why this class is internal? Is it simply because the other collection types use it internally and hide the complexities of a BST from the general masses...or am I way off base?

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  • Multiple indexes for a Java Collection - most basic solution?

    - by chris_l
    Hi, I'm looking for the most basic solution to create multiple indexes on a Java Collection. Required functionality: When a Value is removed, all index entries associated with that value must be removed. Index lookup must be faster than linear search (at least as fast as a TreeMap). Side conditions: It should ideally work with JavaSE (6.0) alone - no extra libraries, if possible. If necessary, then only small (not something like Lucene), common and well tested libraries. No database! Of course, I could write a class that manages multiple Maps myself. But I'd like to know, if it can be done without - while still getting a simple usage similar to using a single indexed java.util.Map. Thanks, Chris

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  • Choosing design method for ladder-like word game.

    - by owca
    I'm trying to build a simple application, with the finished program looking like this : I will also have to implement two different GUI layouts for this. Now I'm trying to figure out the best method to perform this task. My professor told me to introduce Element class with 4 states : - empty - invisible (used in GridLayout) - first letter - other letter I've thought about following solutions (by List I mean any sort of Collection) : 1. Element is a single letter, and each line is Element[]. Game class will be array of arrays Element[]. I guess that's the dumbest way, and the validation might be troublesome. 2. Like previously but Line is a List of Element. Game is an array of Lines. 3. Like previously but Game is a List of Lines. Which one should I choose ? Or maybe do you have better ideas ? What collection would be best if to use one ?

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  • WPF - Dynamically access a specific item of a collection in XAML

    - by Andy T
    Hi, I have a data source ('SampleAppearanceDefinitions'), which holds a single collection ('Definitions'). Each item in the collection has several properties, including Color, which is what I'm interested in here. I want, in XAML, to display the Color of a particular item in the collection as text. I can do this just fine using this code below... Text="{Binding Source={StaticResource SampleAppearanceDefinitions}, Path=Definitions[0].Color}" The only problem is, this requires me to hard-code the index of the item in the Definitions collection (I've used 0 in the example above). What I want to do in fact is to get that value from a property in my current DataContext ('AppearanceID'). One might imagine the correct code to look like this.... Text="{Binding Source={StaticResource SampleAppearanceDefinitions}, Path=Definitions[{Binding AppearanceID}].Color}" ...but of course, this is wrong. Can anyone tell me what the correct way to do this is? Is it possible in XAML only? It feels like it ought to be, but I can't work out or find how to do it. Any help would be greatly appreciated! Thanks! AT

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  • scala 2.8 breakout

    - by oxbow_lakes
    In Scala 2.8, there is an object in scala.collection.package.scala: def breakOut[From, T, To](implicit b : CanBuildFrom[Nothing, T, To]) = new CanBuildFrom[From, T, To] { def apply(from: From) = b.apply() ; def apply() = b.apply() } I have been told that this results in: > import scala.collection.breakOut > val map : Map[Int,String] = List("London", "Paris").map(x => (x.length, x))(breakOut) map: Map[Int,String] = Map(6 -> London, 5 -> Paris) What is going on here? Why is breakOut being called as an argument to my List?

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  • Java Double entry table

    - by Tom
    Hi, Does anyone know a double entry table implementation in java I can download ? I need to do something like this 1 2 3 _______ a| x y z b| h l m c| o a k table.get(a,1) would return x Of course, it should use any Object as key, value, etc Thanks in advance

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