Check out Atomic Chess, our featured variant for November, 2024.

Enter Your Reply

The Comment You're Replying To
H. G. Muller wrote on Sat, Jul 16, 2022 10:53 AM UTC in reply to Daniel Zacharias from 04:34 AM:

You cannot use the variable 'checked' the way your code does (in the functions K and k), because the betza.txt include file does the mate test before the check test (which sets this variable). As a result the variable 'checked' is undefined during the mate test, which apparantly is interpreted as not being in check. So the mate test thinks the King, still in its initial position, can use its initial jumps to escape the check, and hence does not see it as mate.

There currently isn't a good alternative. Perhaps all initial moves of a royal piece should be forbidden when in check. Castling is forbidden when in check, but this is implemented as a property of the castling rather than of the fact that it is defined as an initial move. The mechanism by which this is implemented is that castling creates e.p. squares along the path of the King, including the starting square. And that any move to an e.p. square will always (locust-)capture the royal piece, if that was the last-moved piece. (Otherwise only e.p.-capable pieces would perform the capture.) So what really should happen here is that the initial King moves create an e.p. square on the original King location.

[Edit] This e.p. trick for detecting moving out of check after the fact unfortunately does not work in general: a King could make a leap towards a hopper, and therby activate the hopper for capture to the square it just left. While it would not have been in check by that hopper if it had stayed there. For castlings this cannot happen, as there will also be a Rook in between King origin and any piece that would be standing outside of the Rook. Although a bent hopper might be activated by the Rook. An enemy Grasshopper outside of the Rook would attack the Rook after castling, which could lead to the accusation of having castled through check. Or, when the King would end next to the Rook's original square, to moving through check on its destination square, which would no longer be checked after the castling.

 


Edit Form

Comment on the page A Wizard for GAME-Code Generation

Conduct Guidelines
This is a Chess variants website, not a general forum.
Please limit your comments to Chess variants or the operation of this site.
Keep this website a safe space for Chess variant hobbyists of all stripes.
Because we want people to feel comfortable here no matter what their political or religious beliefs might be, we ask you to avoid discussing politics, religion, or other controversial subjects here. No matter how passionately you feel about any of these subjects, just take it someplace else.
Avoid Inflammatory Comments
If you are feeling anger, keep it to yourself until you calm down. Avoid insulting, blaming, or attacking someone you are angry with. Focus criticisms on ideas rather than people, and understand that criticisms of your ideas are not personal attacks and do not justify an inflammatory response.
Quick Markdown Guide

By default, new comments may be entered as Markdown, simple markup syntax designed to be readable and not look like markup. Comments stored as Markdown will be converted to HTML by Parsedown before displaying them. This follows the Github Flavored Markdown Spec with support for Markdown Extra. For a good overview of Markdown in general, check out the Markdown Guide. Here is a quick comparison of some commonly used Markdown with the rendered result:

Top level header: <H1>

Block quote

Second paragraph in block quote

First Paragraph of response. Italics, bold, and bold italics.

Second Paragraph after blank line. Here is some HTML code mixed in with the Markdown, and here is the same <U>HTML code</U> enclosed by backticks.

Secondary Header: <H2>

  • Unordered list item
  • Second unordered list item
  • New unordered list
    • Nested list item

Third Level header <H3>

  1. An ordered list item.
  2. A second ordered list item with the same number.
  3. A third ordered list item.
Here is some preformatted text.
  This line begins with some indentation.
    This begins with even more indentation.
And this line has no indentation.

Alt text for a graphic image

A definition list
A list of terms, each with one or more definitions following it.
An HTML construct using the tags <DL>, <DT> and <DD>.
A term
Its definition after a colon.
A second definition.
A third definition.
Another term following a blank line
The definition of that term.