The "Dictionary" object returned by the "ToDictionary" method does not act like it would in C#.

[Zarepheth]

As the Subject line says, the Dictionary object return from the List.ToDictionay(keyFunc, ValueFunc) method does not act like the Dictionary objects in .Net. More specifically, I expected to apply the LINQ functions to it, but they are not supported.

Ideally, we would be able to create a Dictionary object directly, rather than going through the List object.

For instance:

const myDict = new Dictionary<TKey, TValue>([
    {"Key":key1, "Value":value1},
    {"Key":key2, "Value":value2},
    {"Key":key3, "Value":value3},
]);

const someKey: TKey;
const myValue: TValue = myDict[someKey];

const myMaxValue = myDict.Max(kvp => kvp.Value);

const valueList = myDict.Select(kvp => kvp.Value).ToList();
const my3rdValue = valueList[2];

[Flavio Corpa]

This is very similar to #56, because a dictionary is just a JS object, you can't really perform any operation afterwards, in this behaviour the library differs from C# obviously but I should came up with some way of doing it, any ideas? 😄

[Zarepheth]

I tried doing my own implementation after writing my post, but was unable to accomplish a working item within the few hours between posting and end of the business day.

Using TypeScript, I had some issues specifying anything other than number or string for the Key type (TKey in my example). Worse, I had to explicitly set the indexer's type in some places. Although use of type constraints allowed TKey in other places. From what I've gather when googling around, one might have to implement non-LINQ-standard methods to set and get values on an internal list.

I also came across a couple other LINQ for TypeScript implementations. At least one has a Dictionary class. Unfortunately, both the other two libraries required that I target ES6 or later. For my current project, I need to target ES5. When I return to work on Monday, I may take a look at that other project's Dictionary implementation. Or maybe see if I can accomplish my task without using a formal LINQ-style Dictionary.

Under the covers, I think the .Net Dictionary implementation is nearly identical to List<KeyValuePair>. At any rate, it's pretty easy to switch between them for my server-side code. I was just hoping to accomplish the same in my client-side code.

[Flavio Corpa]

Nice, thanks for your work and investigation! I think it might be solved using native Maps, but I'm not sure if TypeScript can compile those down to es3/es5 😢

[Flavio Corpa]

@Zarepheth you are soooo going to love tomorrow's PR... ❤️

[Flavio Corpa]

🎉 This issue has been resolved in version 1.12.0 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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