Feature requests: Button to mark cells with possibilities, and button to erase invalidated marks

[NeilGirdhar]

Consider adding the functionality from this awesome script: https://github.com/yusitnikov/sudokupad-sven-magic Namely:

• the "Mark it" button that marks a cell with center marks to indicate possible numbers, and
• the "Sven it" button that erases all invalidated marks, sets naked singles to their remaining value, and recurses.

Yes, it's "cheating", but it honestly takes a lot of the boring parts out of puzzles so that we can focus on the fun stuff.

[NeilGirdhar]

@yusitnikov FYI I submitted this issue :smile: Hope that's okay with you.

[yusitnikov]

It's fine by me. A couple of things to consider if the feature is going to be moved to "core":

• Currently, it's tightly coupled with another custom script that some popular streamers use - "betting tree" (https://github.com/yusitnikov/sudokupad-bet-tree). Streamers mark 1 cell of the grid as a "betting cell", and let the chat guess what's the digit there. Per streamers' request, the "Mark it" button respects this cell, and doesn't fill it when pencilmarking the whole grid. See here: https://github.com/yusitnikov/sudokupad-sven-magic/blob/main/sudokupad-sven-magic.user.js#L96
• Not all puzzles are standard sudoku, so you never know what is the full set of digits to pencilmark. Maybe the puzzle allows to have zeros. Maybe it's a "mean mini" puzzle that allows entering digits 1-9 despite of having a 6x6 grid. Maybe the puzzle contains letters instead of digits. My current solution is to scan the puzzle for which digits and letters were already entered into the grid and assume that it's the set of things to pencilmark into the cell. Sometimes it works fine, sometimes it's being ridiculous (e.g. when people are using the letter tool to mark some cell relations). Maybe you can come out with something smarter.