Added Identity function

[VMRuiz]

Added Identity Method to be able to return fixed values.

Is it quite common that sometimes with just need to return a fixed value.

[renancunha]

Great feature 😃 @VMRuiz! During the schema conversion tests, we needed a feat like this one to fill a specific field with a fixed value.

I have just one consideration: maybe should we stick to the idea of always returns the iterable (with the result), instead of returning the result itself? By doing this we will keep all functions returning the same data structure. We had some discussion about the same situation at #23. In fact, the #23 aims to change the join pipe to follow this approach 👍.

[VMRuiz]

Great feature @VMRuiz! During the schema conversion tests, we needed a feat like this one to fill a specific field with a fixed value.

I have just one consideration: maybe should we stick to the idea of always returns the iterable (with the result), instead of returning the result itself? By doing this we will keep all functions returning the same data structure. We had some discussion about the same situation at #23. In fact, the #23 aims to change the join pipe to follow this approach .

Hello @renancunha ,

I thought about this and I decided to allow the user to get either a single element identity(1) or a iterable identity((1,)) because there are others methods that don't return iterables like join , first, and all of the string methods.

However, I don't have anything agaisn't change it if you all think is better.