🕸Fergus Duniho wrote on Mon, Nov 18, 2019 01:17 AM UTC:
Here are some optimized versions of the B and b functions:
def B
== #0 c1
and flag wccanconvert
or and == #0 g1 flag wgcanconvert
and checkleap #0 #1 1 0
and empty #1
or and checkride #0 #1 1 1 or color #0 nor flag wcmustconvert flag wgmustconvert;
def b
== #0 c8
and flag bccanconvert
or and == #0 g8 flag bgcanconvert
and checkleap #0 #1 1 0
and empty #1
or and checkride #0 #1 1 1 or not color #0 nor flag bcmustconvert flag bgmustconvert;
These do the regular Bishop move first, because that's what the Bishop will do most of the time. This can be done when neither mustconvert flag is set or when the Bishop is on the opposite color from the one it starts from. So, if a White Bishop is on a dark square (color = 1), or a Black Bishop is on a light square (color = 0), it can move as a Bishop. Testing for color #0 is quicker than testing for == color #0 1, and testing for not color #0 is faster than testing for == color #0 0, though they are a little bit more obfuscated. With regular Bishop moves out of the way, the function uses a series of breaking conditions to test whether a conversion move is possible. It first tests for conditions common to both conversion moves, testing for the less expensive one first. Also, given that these functions will frequently be used in testing whether a Bishop is attacking a King, including empty #1 as the first condition of the conversion move saves it from the trouble of checking for anything else when used for that purpose. It then tests whether it is legally converting from the g square, and if not, it uses a series of breaking conditions to test whether it is legally converting from the c square.
Here are some optimized versions of the B and b functions:
These do the regular Bishop move first, because that's what the Bishop will do most of the time. This can be done when neither mustconvert flag is set or when the Bishop is on the opposite color from the one it starts from. So, if a White Bishop is on a dark square (color = 1), or a Black Bishop is on a light square (color = 0), it can move as a Bishop. Testing for color #0 is quicker than testing for == color #0 1, and testing for not color #0 is faster than testing for == color #0 0, though they are a little bit more obfuscated. With regular Bishop moves out of the way, the function uses a series of breaking conditions to test whether a conversion move is possible. It first tests for conditions common to both conversion moves, testing for the less expensive one first. Also, given that these functions will frequently be used in testing whether a Bishop is attacking a King, including empty #1 as the first condition of the conversion move saves it from the trouble of checking for anything else when used for that purpose. It then tests whether it is legally converting from the g square, and if not, it uses a series of breaking conditions to test whether it is legally converting from the c square.