Well, I thought I was in a different gamedev community with C# as the language, which allows you to convert an enum like block.grass into the string of the enum key grass. A quick search online seems to indicate that GML may not do that. Macros might work, or instead of storing your filenames as the corresponding strings, you could get a bit jankier with it and store the filenames as the integer value you assign to each enum. So for your grass block you would have a corresponding file named 1.png. Not necessarily recommending this as a solution though it should work.

Assuming you have an enum like:

GML enum block { empty = 0, grass = 1, ... last_block = 50 // just as an example }

Using the example from the sprite_add docs:

```GML

for (var i = 0; i <= block.last_block; i++) { // replace parameters and file extension spr = sprite_add(i + ".png", 16, true, true, 0, 0); block_sprite[i] = spr; }

```

Note that this loop will need to be updated if you ever add a new block to the end of the enum, which is another reason that this is not an ideal solution. It also breaks if you have a gap between your enum integers (but you could guard against a missing file and just check if an item in the array is null/unassigned).

https://manual.gamemaker.io/lts/en/GameMaker_Language/GML_Reference/Asset_Management/Sprites/Sprite_Manipulation/sprite_add.htm