zig boolean iterator

bool_iterators.zig

const BoolIterator = struct {
    bools: []const bool,
    cursor: usize = 0,
    const Self = @This();
    pub fn next(self: *Self) ?bool {
        if (self.cursor < self.bools.len) {
            const ret = self.bools[self.cursor];
            self.cursor += 1;
            return ret;
        }
        return null;
    }
    pub fn reset(self: *Self) void {
        self.cursor = 0;
    }
};


/// 1/1 test_0...
/// while (it.next())...
/// 0 true
/// 1 true
/// 2 false
/// 3 true
/// 4 true
/// while (true)... it.next() orelse break
/// 0 true
/// 1 true
/// 2 false
/// 3 true
/// 4 true
/// while (true)... const maybe_val = it.next();... if (maybe_val == null) break;
/// 0 true
/// 1 true
/// 2 false
/// 3 true
/// 4 true
/// OK
/// All 1 tests passed.
test {
    var it = BoolIterator{
        .bools = &[_]bool{ true, true, false, true, true },
    };

    std.debug.print("\n", .{});
    std.debug.print("while (it.next())...\n", .{});
    while (it.next()) |val| {
        std.debug.print("{} {}\n", .{ it.cursor - 1, val });
    }
    it.reset();

    std.debug.print("while (true)... it.next() orelse break\n", .{});
    while (true) {
        const val = it.next() orelse break;
        std.debug.print("{} {}\n", .{ it.cursor - 1, val });
    }
    it.reset();

    std.debug.print("while (true)... const maybe_val = it.next();... if (maybe_val == null) break;\n", .{});
    while (true) {
        const maybe_val = it.next();
        if (maybe_val == null) break;
        const val = maybe_val.?;
        std.debug.print("{} {}\n", .{ it.cursor - 1, val });
    }
}