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# Ad-hoc userland implementation of comparison ops set '<0 { != 0 (& 9223372036854775808 (get args 0)) } set '< { <0 (- (get args 0) (get args 1)) } set '>= { ! (< (get args 0) (get args 1)) } set '<= { # No, these variable names aren't great inset args '(_<=_x _<=_y) || (= _<=_x _<=_y) (< _<=_x _<=_y) } set '> { ! (<= (get args 0) (get args 1)) } print (< 4 5) sp (<= 4 5) sp (> 4 5) sp (>= 4 5) ln print (< 9 2) sp (<= 9 2) sp (> 9 2) sp (>= 9 2) ln print (< 7 7) sp (<= 7 7) sp (> 7 7) sp (>= 7 7) ln

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# Ad-hoc userland implementation of comparison ops set '<0 { != 0 (& 9223372036854775808 (get args 0)) } set '< { <0 (- (get args 0) (get args 1)) } set '>= { ! (< (get args 0) (get args 1)) } set '<= { # No, these variable names aren't great inset args '(_<=_x _<=_y) || (= _<=_x _<=_y) (< _<=_x _<=_y) } set '> { ! (<= (get args 0) (get args 1)) } print (< 4 5) sp (<= 4 5) sp (> 4 5) sp (>= 4 5) ln print (< 9 2) sp (<= 9 2) sp (> 9 2) sp (>= 9 2) ln print (< 7 7) sp (<= 7 7) sp (> 7 7) sp (>= 7 7) ln
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mcc (mcc@mastodon.social)'s status on Friday, 11-Apr-2025 03:06:43 JST mcc
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Anyway, I like testing things before I use them, so after implementing my "if" and "while" I decide to write a simple Fizzbuzz program. This causes me to immediately realize—
I FORGOT TO IMPLEMENT > AND <
I just forgot!! Fortunately I *did* include bit arithmetic ops, so I implement <, >, <=, >= in userland as well, by testing bit (1<<63) as a proxy for 2's compliment negative. This is actually a little worrisome. I'm not sure if this code truly "works" or if I'm just leveraging UB in Rust.

In conversation about 12 days ago from mastodon.social permalink