tiny.accy.axis.roles

1const std = @import("std");23pub const Failure = enum {4    out_of_range,5    duplicate,6};78fn appearsInPriorGroup(9    groups: []const []const i64,10    group_index: usize,11    axis: i64,12) bool {13    for (groups[0..group_index]) |prior| {14        for (prior) |seen| {15            if (seen == axis) return true;16        }17    }18    return false;19}2021pub fn check(22    rank: usize,23    groups: []const []const i64,24) ?Failure {25    for (groups, 0..) |group, group_index| {26        for (group, 0..) |axis, axis_index| {27            const index = std.math.cast(usize, axis) orelse28                return .out_of_range;29            if (index >= rank) return .out_of_range;30            if (appearsInPriorGroup(groups, group_index, axis)) {31                return .duplicate;32            }33            for (group[0..axis_index]) |seen| {34                if (seen == axis) return .duplicate;35            }36        }37    }38    return null;39}4041pub fn groupsOverlap(groups: []const []const i64) bool {42    for (groups, 0..) |group, group_index| {43        for (group) |axis| {44            if (appearsInPriorGroup(groups, group_index, axis)) return true;45        }46    }47    return false;48}4950test "axis role groups form a partial permutation" {51    try std.testing.expect(check(4, &.{ &.{ 2, 0 }, &.{3} }) == null);52    try std.testing.expectEqual(53        Failure.out_of_range,54        check(2, &.{&.{-1}}).?,55    );56    try std.testing.expectEqual(57        Failure.out_of_range,58        check(2, &.{&.{2}}).?,59    );60    try std.testing.expectEqual(61        Failure.duplicate,62        check(2, &.{&.{ 0, 0 }}).?,63    );64    try std.testing.expectEqual(65        Failure.duplicate,66        check(2, &.{ &.{0}, &.{0} }).?,67    );68    try std.testing.expect(!groupsOverlap(&.{ &.{ 2, 0 }, &.{3} }));69    try std.testing.expect(groupsOverlap(&.{ &.{0}, &.{0} }));70}

1pub const roles = @import("roles.zig");