If this is 'Post-Move' code, the Pawn has already landed on the to-square, so that it is no longer empty?
Correct.
verify == captured @;
verify not capture; should also work.
For my understanding: why is it necessary to copy the screen to a variable, before testing it. Is there a problem with writing
capture screen;
When I started what became the GAME Code language, I started with commands, which simply took arguments, and I let arguments be separated by spaces. I added expressions to the language later, and I used Polish notation, which also used spaces as separators, because it was easier to implement than infix syntax with parentheses, and its prefix syntax would be quicker to interpret too, which matters for an interpreted language written in another interpreted language. Because of these choices, it's not easy to distinguish between an expression and a list of arguments. So, instead of letting an expression be used anyplace an argument can be used, only some commands can interpret expressions. These include commands for setting variables or for controlling the flow of the program.
Correct.
verify not capture;should also work.When I started what became the GAME Code language, I started with commands, which simply took arguments, and I let arguments be separated by spaces. I added expressions to the language later, and I used Polish notation, which also used spaces as separators, because it was easier to implement than infix syntax with parentheses, and its prefix syntax would be quicker to interpret too, which matters for an interpreted language written in another interpreted language. Because of these choices, it's not easy to distinguish between an expression and a list of arguments. So, instead of letting an expression be used anyplace an argument can be used, only some commands can interpret expressions. These include commands for setting variables or for controlling the flow of the program.