pathetic piss kitten (@kitten)

pathetic piss kitten @kitten@elizabeth.cat

my archenemy, nested ternary operators

@siblingsofthevoid@void.lgbt

@kitten no one should ever nest ternaries… I have always thought that to be absolutely terrible practice and it is horribly unreadable.

Erin 💽✨ @erincandescent@erincandescent.net

@kitten you would hate your average (System)Verilog file, its practically standard to write things like

assign x = condition_a ? foo :
           condition_b ? bar :
           condition_c ? baz :
           condition_d ? qux :
                         quux;

Daphne Preston-Kendal @dpk@chaos.social

@erincandescent @kitten So you know how they came out with a JS edition of SICP recently

Yeah, well, the original Scheme version has a section that depends heavily on ‘if’ and ‘cond’ being expressions and not statements. JS ‘if’ is a statement and can’t be used in a context that expects a value.

… how do you think they solved this 😬

sourceacademy.org/sicpjs/1.1.6

pathetic piss kitten @kitten@elizabeth.cat

@dpk @erincandescent

pathetic piss kitten @kitten@elizabeth.cat

@erincandescent nooooo

although at least this is a serially nested ternary. the one I saw had subternaries in both branches of the main ternary

Erin 💽✨ @erincandescent@erincandescent.net

@kitten it's also pretty common to see "opencoded" conditions e.g. when you can assume due to structural factors that only one condition will ever be true:

conds_onehot: assert property ($onehot0({condition_a, condition_b, condition_c, condition_d, condition_e}));

assign x = ({8{condition_a}} & foo)
         | ({8{condition_b}} & bar)
         | ({8{condition_c}} & baz)
         | ({8{condition_d}} & qux)
         | ({8{condition_e}} & quux);

HDL is a weird world!

Erin 💽✨ @erincandescent@erincandescent.net

@kitten ({8{foo}} is Verilog for repeat foo 8x)

pathetic piss kitten @kitten@elizabeth.cat

@erincandescent .......why do they do that?

Erin 💽✨ @erincandescent@erincandescent.net

@kitten produces smaller and hence faster synthesis outputs (assuming that the synthesis tool couldn't prove the mutual exclusiveness of the conditions in the original, which it probably can't. They can be pretty dumb)

fungus (penicillin producer) @hypha@cafe.mycelium.locahlo.st

@kitten @erincandescent who doesn’t like some cyclomatic complexity? :D

Persephone @mindpersephone@spookygirl.boo

@kitten burn them with fire!