diff options
Diffstat (limited to 'std/Number/Binary.bruijn')
| -rw-r--r-- | std/Number/Binary.bruijn | 27 |
1 files changed, 22 insertions, 5 deletions
diff --git a/std/Number/Binary.bruijn b/std/Number/Binary.bruijn index a056538..77ce09c 100644 --- a/std/Number/Binary.bruijn +++ b/std/Number/Binary.bruijn @@ -163,6 +163,9 @@ not-eq? not! ∘∘ eq? ⧗ Binary → Binary → Boolean :test ([[[1 (0 2)]]] ≠? [[[1 (0 2)]]]) (false) :test ([[[1 (0 2)]]] ≠? (+2b)) (true) +# prefix for comparing functions +?‣ &eq? + # adds 1 to a binary number (can introduce leading 0s) inc [~(0 z a¹ a⁰)] ⧗ Binary → Binary z (+0b) : (+1b) @@ -196,7 +199,7 @@ complement [[[[3 2 0 1]]]] ⧗ Binary → Binary :test (-*(+42b)) ([[[1 (0 (1 (0 (1 (0 2)))))]]]) # inverts a binary number by complementing and incrementing (2's complement) -# don't forget to pad the number with zeroes if needed +# don't forget to pad the number with 0s if needed invert ++‣ ∘ -*‣ ⧗ Binary → Binary -‣ invert @@ -204,9 +207,9 @@ invert ++‣ ∘ -*‣ ⧗ Binary → Binary :test (-(+0b)) ((+1b)) :test (-(+1b)) ((+1b)) -# pads a binary number with zeroes until its as long a another binary number -# TODO: this could probably be done without list magic -pad [[binary! (pad-right ∀(list! %1) b⁰ (list! 0))]] ⧗ Binary → Binary → Binary +# pads a binary number with 0s until it's as long a another binary number +# TODO: this could be done without list magic (see Ternary) +pad [[binary! (pad-right ∀(list! %1) b⁰ (list! %0))]] ⧗ Binary → Binary → Binary :test (pad (+5b) [[[1 2]]]) ([[[1 (0 (0 2))]]]) @@ -248,7 +251,7 @@ sub* [[abs 1 →^0]] ⧗ Binary → Binary → Binary # subs two binary numbers # uses addition but with two's complement # TODO: isn't very performant ⇒ replace with sub* -# TODO: gives wrong results if b>a in a-b +# TODO: gives fun results if b>a in a-b sub [[(0 =? 1) (+0b) -((pad 1 0) + -(pad 0 1))]] ⧗ Binary → Binary → Binary …-… sub @@ -279,6 +282,20 @@ div² [~(0 z a¹ a⁰)] ⧗ Binary → Binary :test (/²(+6b) =? (+3b)) (true) :test (/²(+5b) =? (+2b)) (true) +# ceiled integer log2 by counting bits +# also counts leading 0s +log2* [0 (+0b) inc inc] ⧗ Binary → Binary + +# ceiled integer log2 by counting bits +log2 log2* ∘ strip ⧗ Binary → Binary + +:test ((log2 (+1b)) =? (+1b)) (true) +:test ((log2 (+2b)) =? (+2b)) (true) +:test ((log2 (+3b)) =? (+2b)) (true) +:test ((log2 (+4b)) =? (+3b)) (true) +:test ((log2 (+32b)) =? (+6b)) (true) +:test ((log2 (+48b)) =? (+6b)) (true) + # returns true if the number is even (remainder mod 2 == 0) even? ¬‣ ∘ lsb ⧗ Binary → Boolean |