some common puzzle types that would be straightforward to add

[robx]

• Snake ✅
• Mine Sweeper ✅
• Zeltplatz / Tents and trees ✅
• Anglers ✅
• Coral / Koralle ✅

[robx]

some other types that would be nice to have but need some more serious work (a piece bank particularly):

• (pentomino) statue park, perhaps via pentominous borders, pentominous ✅
• battleships ✅
• dominos
• japanese sums (multiple rows of outside clues)

[x-sheep]

Snake has a lot of different clue types, none of which can really be classified as a variant. Other than the numbers on the edges, I've seen:

• Numbers in the grid
• Unknown snake parts (question marks)
• Snake endpoints without a number
• Given snake length
• Empty cells

Which of these do we want to support?

[robx]

That's a good point. I have an idea of "standard" snake in mind, but that's probably mostly due to what's common at Logic Masters Germany. I'd suggest going for:

• no numbers in grid, no length, no question marks, no empty cells
• givens are:
  • outside clues (not necessarily all of them)
  • snake ends (don't have to be given)

[tausbn]

The presentation in Toketa (vol. 6) matches what Rob lists, with the addition of cells-that-are-snake-but-not-endpoints. Endpoints are indicated with black circles, non-endpoints with white circles. Neither of these are required, nor are outside clues necessarily total.

There's also the question of presentation: should the snake cells be shaded or drawn as a continuous line? (I used to do the former, but switched to the latter as it's easier on paper.)

[robx]

That seems fine (white circles as non-endpoints).

Presentation should be fully shaded cells.