C#•6mo ago

Making my functions more generic

right now i have several functions that do essentially the same thing, the only difference being the type they take in i have two data classes that have different data but both share one variable, a Tag class i have two different functions to go through my database and get these data objects with a matching Tag, how would i go about combining these into one? making them both inherit from a class with a Tag or could i make the functions themselves generic?

16 Replies

Tvde1•6mo ago

could you show us the functions? I would define an interface which has the property that it needs from both, and then you can do

public Task DoSomething<TEntity>(TEntity entity)
    where TEntity : INeeded
{
    entity.Id = ...;
}

interface TEntity
{
    public int Id { get; }
}

public Task DoSomething<TEntity>(TEntity entity)
    where TEntity : INeeded
{
    entity.Id = ...;
}

interface TEntity
{
    public int Id { get; }
}

AdamOP•6mo ago

public Dictionary<string, Stat> StatsWithTag(string tagName)
{
    Dictionary<string, Stat> stats = new();
    foreach (var stat in statsDB.Stats)
    {
        foreach (var statTag in stat.Tags)
        {
            if (statTag.TagName == tagName)
                stats.Add(stat.StatName, new(stat));
        }
    }

    return stats;
}

public Dictionary<string, Stat> StatsWithTag(string tagName)
{
    Dictionary<string, Stat> stats = new();
    foreach (var stat in statsDB.Stats)
    {
        foreach (var statTag in stat.Tags)
        {
            if (statTag.TagName == tagName)
                stats.Add(stat.StatName, new(stat));
        }
    }

    return stats;
}

other one is the same but with another class instead of Stat

Tvde1•6mo ago

a better way to do this is:

public Dictionary<string, Stat> StatsWithTag(string tagName)
{
    return statsDB.Stats
        .Where(stat => stat.TagName == tagName)
        .ToDictionary(stat => stat.StatName);
}

public Dictionary<string, Stat> StatsWithTag(string tagName)
{
    return statsDB.Stats
        .Where(stat => stat.TagName == tagName)
        .ToDictionary(stat => stat.StatName);
}

I believe this gives the same result and it is recommended to make this async, but I will leave this up to you

AdamOP•6mo ago

i was under the impression loops are a bit more performant than LINQ, but i'm not sure if it matters in my use case so that does look a lot cleaner i haven't familiarized myself with async, why do you say it's recommended here? and why is this a task and what does where TEntity : INeeded do?

Tvde1•6mo ago

it is a little bit complicated, but in this case, the LINQ is more performant. Your example does: 1. Get all Stats from the database 2. Loop over all the stats 3. If it matches the tag name, add to dictionary The example I showed uses IQueryable, which entity framework is built on to do the following 1. Only take from the database, all the Stats which match the tag name. (This will do the query:

SELECT * FROM Stats
WHERE TagName = 'your-tag-name'

SELECT * FROM Stats
WHERE TagName = 'your-tag-name'

2. it loops over only the results which are found and makes a dictionary

AdamOP•6mo ago

oh i see that's sick, ty

Tvde1•6mo ago

only when you do * ToList() * ToDictionary() * First() etc, does your query get executed. So any .Where() that you do, will be translated to SQL for better performance

AdamOP•6mo ago

gotcha gotcha not sure if you saw this, could you explain the TEntity interface implementation?

Tvde1•6mo ago

for your use case I wouldn't deduplicate it if you wanted to, it would look something like

interface ITaggable
{
    public string TagName { get; }
    public string Name { get; }
}

public Dictionary<string, T> StatsWithTag<T>(DbSet<T> dbSet, string tagName)
{
    return dbSet
        .Where(stat => stat.TagName == tagName)
        .ToDictionary(stat => stat.Name);
}

class Stat : ITaggable
{
    // your properties
    public string StatName { get; set; }
    ...

    // required because of the interface
    public string TagName { get; }

    // Required so the interface can get the name
    public string Name => StatName;
}

class SomethingElse : ITaggable
{
    // your properties
    public string MySomethingName { get; set; }
    ...

    // required because of the interface
    public string TagName { get; }

    // Required so the interface can get the name
    public string Name => MySomethingName;
}

interface ITaggable
{
    public string TagName { get; }
    public string Name { get; }
}

public Dictionary<string, T> StatsWithTag<T>(DbSet<T> dbSet, string tagName)
{
    return dbSet
        .Where(stat => stat.TagName == tagName)
        .ToDictionary(stat => stat.Name);
}

class Stat : ITaggable
{
    // your properties
    public string StatName { get; set; }
    ...

    // required because of the interface
    public string TagName { get; }

    // Required so the interface can get the name
    public string Name => StatName;
}

class SomethingElse : ITaggable
{
    // your properties
    public string MySomethingName { get; set; }
    ...

    // required because of the interface
    public string TagName { get; }

    // Required so the interface can get the name
    public string Name => MySomethingName;
}

than you can do

var statsByName = StatsWithTag(statsDB.Stats, "my-tag");
var othersByName = StatsWithTag(statsDB.SomethingElse, "my-other-tag");

var statsByName = StatsWithTag(statsDB.Stats, "my-tag");
var othersByName = StatsWithTag(statsDB.SomethingElse, "my-other-tag");

But I wouldn't make it more complicated than it needs to be

AdamOP•6mo ago

okay i see i see tyty i'll try this out oh and is there a similarly more performant way to implement this function? i haven't changed the Stat class to implement an interface yet so keep that in mind i use the dict of stats i got from the other function and then take in another dict of stats that i want to add stats to, but only add them if the dict doesn't already have them

public void AddMissingStatsWithTag(Dictionary<string, Stat> dict, string tagName)
{
    Dictionary<string, Stat> fullDict = StatsWithTag(tagName);

    foreach (KeyValuePair<string, Stat> pair in fullDict)
    {
        if (!dict.ContainsKey(pair.Key))
        {
            dict.Add(pair.Key, pair.Value);
        }
    }
}

public void AddMissingStatsWithTag(Dictionary<string, Stat> dict, string tagName)
{
    Dictionary<string, Stat> fullDict = StatsWithTag(tagName);

    foreach (KeyValuePair<string, Stat> pair in fullDict)
    {
        if (!dict.ContainsKey(pair.Key))
        {
            dict.Add(pair.Key, pair.Value);
        }
    }
}

alternatively a way to do this innately without a function, i've looked for that but couldn't find a good solution

Tvde1•6mo ago

This one is fine It's a bit strange why there would be things missing but alright 😁

Joschi•6mo ago

An minor improvement would be to use dict.TryAdd() instead of the if followed by add

AdamOP•6mo ago

ohh nice tip ty i call this function to add all stats basically since each data object will need a different set of stats when my data objects are initialised since i don't know how to do it at construction (in unity)

AdamOP•6mo ago

how would i do this if Tag isn't a single string but a list?

AdamOP•6mo ago

also had a problem here i'm not sure about

Tvde1•6mo ago

you have your ) a bit misplaced

return statsDB.Stats
    .Where(s => s.PrimaryTags.Contains(tagName))
    .ToList();

return statsDB.Stats
    .Where(s => s.PrimaryTags.Contains(tagName))
    .ToList();

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