refactor(users/sterni/nix): move generic number operation into num

We omit type checks for performance reasons in most places currently, so
the library grouping is important in showing people what to use for what
sort of input. The moved functions make sense to use with floats as
well, so we'll move them to the num library. Some of the remaining
functions could theoretically be adapted and moved, but aren't for now.

Change-Id: Ifdecaa60be594f4438b2a58b9ea6445e2da080e3
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9007
Tested-by: BuildkiteCI
Reviewed-by: sterni <sternenseemann@systemli.org>
This commit is contained in:
sterni 2023-08-05 15:39:56 +02:00
parent dbdb2575cf
commit 984ea69386
6 changed files with 64 additions and 45 deletions

View file

@ -10,7 +10,7 @@ let
inherit (depot.users.sterni.nix)
char
string
int
num
fun
;
@ -18,10 +18,10 @@ let
testAllCharConversion = it "tests conversion of all chars" [
(assertEq "char.chr converts to char.allChars"
(builtins.genList (fun.rl char.chr (int.add 1)) 255)
(builtins.genList (fun.rl char.chr (num.add 1)) 255)
charList)
(assertEq "char.ord converts from char.allChars"
(builtins.genList (int.add 1) 255)
(builtins.genList (num.add 1) 255)
(builtins.map char.ord charList))
];

View file

@ -2,31 +2,22 @@
let
# TODO(sterni): implement nix.float and figure out which of these
# functions can be split out into a common nix.num
# library.
inherit (depot.users.sterni.nix)
string
num
;
inherit (builtins)
bitOr
bitAnd
bitXor
mul
div
add
sub
;
abs = i: if i < 0 then -i else i;
exp = base: pow:
if pow > 0
then base * (exp base (pow - 1))
else if pow < 0
then 1.0 / exp base (abs pow)
then 1.0 / exp base (num.abs pow)
else 1;
bitShiftR = bit: count:
@ -52,7 +43,7 @@ let
in
if int == 0
then "0"
else "${sign}${go (abs int)}";
else "${sign}${go (num.abs int)}";
fromHexMap = builtins.listToAttrs
(lib.imap0 (i: c: { name = c; value = i; })
@ -94,26 +85,17 @@ let
odd = x: bitAnd x 1 == 1;
even = x: bitAnd x 1 == 0;
# div and mod behave like quot and rem in Haskell,
# i. e. they truncate towards 0
inherit (builtins) div;
mod = a: b: let res = a / b; in a - (res * b);
inRange = a: b: x: x >= a && x <= b;
sum = builtins.foldl' (a: b: a + b) 0;
in
{
inherit
maxBound
minBound
abs
exp
odd
even
add
sub
mul
div
mod
bitShiftR
@ -123,7 +105,5 @@ in
bitXor
toHex
fromHex
inRange
sum
;
}

View file

@ -15,9 +15,6 @@ let
;
testBounds = it "checks minBound and maxBound" [
# this is gonna blow up in my face because
# integer overflow is undefined behavior in
# C++, so most likely anything could happen?
(assertEq "maxBound is the maxBound" true
(int.maxBound + 1 < int.maxBound))
(assertEq "minBound is the minBound" true
@ -321,7 +318,6 @@ let
testBasic = it "checks basic int operations" [
(assertEq "122 is even" (int.even 122 && !(int.odd 122)) true)
(assertEq "123 is odd" (int.odd 123 && !(int.even 123)) true)
(assertEq "abs -4959" (int.abs (-4959)) 4959)
];
expNumbers = [
@ -374,7 +370,7 @@ let
checkShiftLMulExp = n:
assertEq "${toString n} >> 6 == ${toString n} * 2 ^ 6"
(int.bitShiftL n 5)
(int.mul n (int.exp 2 5));
(n * (int.exp 2 5));
testBit = it "checks bitwise operations" (lib.flatten [
(builtins.map checkShift shifts)

View file

@ -0,0 +1,16 @@
{ ... }:
rec {
inherit (builtins)
mul
div
add
sub
;
abs = i: if i < 0 then -i else i;
inRange = a: b: x: x >= a && x <= b;
sum = builtins.foldl' (a: b: a + b) 0;
}

View file

@ -0,0 +1,26 @@
{ depot, ... }:
let
inherit (depot.nix.runTestsuite)
runTestsuite
it
assertEq
;
inherit (depot.users.sterni.nix)
num
;
testsBasic = it "tests basic operations" [
(assertEq "abs -4959" (num.abs (-4959)) 4959)
(assertEq "sum" (num.sum [ 123 321 1.5 ]) (123 + 321 + 1.5))
(assertEq "inRange"
(builtins.map (num.inRange 1.0 5) [ 0 0.5 3 4 4.5 5.5 5 6 ])
[ false false true true true false true false ])
];
in
runTestsuite "nix.num" [
testsBasic
]

View file

@ -6,6 +6,7 @@ let
char
flow
fun
num
int
string
util
@ -46,17 +47,17 @@ let
# byte position as an index starting with 0
pos:
let
defaultRange = int.inRange 128 191;
defaultRange = num.inRange 128 191;
secondBytePredicate = flow.switch first [
[ (int.inRange 194 223) defaultRange ] # C2..DF
[ 224 (int.inRange 160 191) ] # E0
[ (int.inRange 225 236) defaultRange ] # E1..EC
[ 237 (int.inRange 128 159) ] # ED
[ (int.inRange 238 239) defaultRange ] # EE..EF
[ 240 (int.inRange 144 191) ] # F0
[ (int.inRange 241 243) defaultRange ] # F1..F3
[ 244 (int.inRange 128 143) ] # F4
[ (num.inRange 194 223) defaultRange ] # C2..DF
[ 224 (num.inRange 160 191) ] # E0
[ (num.inRange 225 236) defaultRange ] # E1..EC
[ 237 (num.inRange 128 159) ] # ED
[ (num.inRange 238 239) defaultRange ] # EE..EF
[ 240 (num.inRange 144 191) ] # F0
[ (num.inRange 241 243) defaultRange ] # F1..F3
[ 244 (num.inRange 128 143) ] # F4
[ (fun.const true) null ]
];
@ -225,10 +226,10 @@ let
# Note that this doesn't check if the Unicode codepoint is allowed,
# but rather allows all theoretically UTF-8-encodeable ones.
count = flow.switch cp [
[ (int.inRange 0 127) 1 ] # 00000000 0xxxxxxx
[ (int.inRange 128 2047) 2 ] # 00000yyy yyxxxxxx
[ (int.inRange 2048 65535) 3 ] # zzzzyyyy yyxxxxxx
[ (int.inRange 65536 1114111) 4 ] # 000uuuuu zzzzyyyy yyxxxxxx,
[ (num.inRange 0 127) 1 ] # 00000000 0xxxxxxx
[ (num.inRange 128 2047) 2 ] # 00000yyy yyxxxxxx
[ (num.inRange 2048 65535) 3 ] # zzzzyyyy yyxxxxxx
[ (num.inRange 65536 1114111) 4 ] # 000uuuuu zzzzyyyy yyxxxxxx,
# capped at U+10FFFF
[ (fun.const true) (builtins.throw invalidCodepointMsg) ]