movefasta/nixpkgs
1
0
Fork 0
mirror of https://github.com/NixOS/nixpkgs.git synced 2025-06-10 19:55:41 +03:00
Code Issues Projects Releases Packages Wiki Activity

Merge pull request #243520 from tweag/lib.lists.commonPrefix

Browse source 
`lib.lists.{findFirstIndex,commonPrefix}`: init
This commit is contained in:
Silvan Mosberger 2023-07-26 23:14:58 +02:00 • committed by GitHub
commit bd74cdfb2e
No known key found for this signature in database
GPG key ID: 4AEE18F83AFDEB23
2 changed files with 124 additions and 29 deletions
Download patch file Download diff file Expand all files Collapse all files

83
lib/tests/misc.nix
View file

@ -500,6 +500,39 @@ runTests {
expected = { a = [ 2 3 ]; b = [7]; c = [8];};
};
testListCommonPrefixExample1 = {
expr = lists.commonPrefix [ 1 2 3 4 5 6 ] [ 1 2 4 8 ];
expected = [ 1 2 ];
};
testListCommonPrefixExample2 = {
expr = lists.commonPrefix [ 1 2 3 ] [ 1 2 3 4 5 ];
expected = [ 1 2 3 ];
};
testListCommonPrefixExample3 = {
expr = lists.commonPrefix [ 1 2 3 ] [ 4 5 6 ];
expected = [ ];
};
testListCommonPrefixEmpty = {
expr = lists.commonPrefix [ ] [ 1 2 3 ];
expected = [ ];
};
testListCommonPrefixSame = {
expr = lists.commonPrefix [ 1 2 3 ] [ 1 2 3 ];
expected = [ 1 2 3 ];
};
testListCommonPrefixLazy = {
expr = lists.commonPrefix [ 1 ] [ 1 (abort "lib.lists.commonPrefix shouldn't evaluate this")];
expected = [ 1 ];
};
# This would stack overflow if `commonPrefix` were implemented using recursion
testListCommonPrefixLong =
let
longList = genList (n: n) 100000;
in {
expr = lists.commonPrefix longList longList;
expected = longList;
};
testSort = {
expr = sort builtins.lessThan [ 40 2 30 42 ];
expected = [2 30 40 42];
@ -530,45 +563,55 @@ runTests {
expected = false;
};
testFindFirstExample1 = {
expr = findFirst (x: x > 3) 7 [ 1 6 4 ];
expected = 6;
testFindFirstIndexExample1 = {
expr = lists.findFirstIndex (x: x > 3) (abort "index found, so a default must not be evaluated") [ 1 6 4 ];
expected = 1;
};
testFindFirstExample2 = {
expr = findFirst (x: x > 9) 7 [ 1 6 4 ];
expected = 7;
testFindFirstIndexExample2 = {
expr = lists.findFirstIndex (x: x > 9) "a very specific default" [ 1 6 4 ];
expected = "a very specific default";
};
testFindFirstEmpty = {
expr = findFirst (abort "when the list is empty, the predicate is not needed") null [];
testFindFirstIndexEmpty = {
expr = lists.findFirstIndex (abort "when the list is empty, the predicate is not needed") null [];
expected = null;
};
testFindFirstSingleMatch = {
expr = findFirst (x: x == 5) null [ 5 ];
expected = 5;
testFindFirstIndexSingleMatch = {
expr = lists.findFirstIndex (x: x == 5) null [ 5 ];
expected = 0;
};
testFindFirstSingleDefault = {
expr = findFirst (x: false) null [ (abort "if the predicate doesn't access the value, it must not be evaluated") ];
testFindFirstIndexSingleDefault = {
expr = lists.findFirstIndex (x: false) null [ (abort "if the predicate doesn't access the value, it must not be evaluated") ];
expected = null;
};
testFindFirstNone = {
expr = builtins.tryEval (findFirst (x: x == 2) null [ 1 (throw "the last element must be evaluated when there's no match") ]);
testFindFirstIndexNone = {
expr = builtins.tryEval (lists.findFirstIndex (x: x == 2) null [ 1 (throw "the last element must be evaluated when there's no match") ]);
expected = { success = false; value = false; };
};
# Makes sure that the implementation doesn't cause a stack overflow
testFindFirstBig = {
expr = findFirst (x: x == 1000000) null (range 0 1000000);
testFindFirstIndexBig = {
expr = lists.findFirstIndex (x: x == 1000000) null (range 0 1000000);
expected = 1000000;
};
testFindFirstLazy = {
expr = findFirst (x: x == 1) 7 [ 1 (abort "list elements after the match must not be evaluated") ];
expected = 1;
testFindFirstIndexLazy = {
expr = lists.findFirstIndex (x: x == 1) null [ 1 (abort "list elements after the match must not be evaluated") ];
expected = 0;
};
testFindFirstExample1 = {
expr = lists.findFirst (x: x > 3) 7 [ 1 6 4 ];
expected = 6;
};
testFindFirstExample2 = {
expr = lists.findFirst (x: x > 9) 7 [ 1 6 4 ];
expected = 7;
};
# ATTRSETS