Re: [Tarantool-patches] [PATCH v2 1/2] uuid: support comparison of uuid values in Lua

[Igor Munkin <imun@tarantool.org>]

Oleg,

Thanks for the patch! Considering the version on the remote branch, LGTM
except a single nit below.

On 18.11.20, olegrok@tarantool.org wrote:
> From: Oleg Babin <babinoleg@mail.ru>
> 
> Since Tarantool has uuid data type sometimes we want to compare
> uuid vaues as it's possible for primitive types and decimals. This
> patch exports function for uuid comparison and implements le and
> lt metamethods for uuid type.

Minor: Strictly saying, you're right, but AFAICS we usually use the key
name (i.e. __le and __lt) for metamethods in description.

> 
> Closes #5511
> 
> @TarantoolBot document
> Title: uuid comparison is supported
> 
> Currently comparison between uuid values is supported.
> Example:
> ```lua
> u1 = uuid.fromstr('aaaaaaaa-aaaa-4000-b000-000000000001')
> u2 = uuid.fromstr('bbbbbbbb-bbbb-4000-b000-000000000001')
> 
> u1 > u2  -- false
> u1 >= u2 -- false
> u1 <= u2 -- true
> u1 < u2  -- true
> ```
> ---
> Issue: https://github.com/tarantool/tarantool/issues/5511
> Branch: https://github.com/tarantool/tarantool/tree/olegrok/5511-uuid-cmp-v2
> 
>  src/exports.h          |  1 +
>  src/lua/uuid.lua       | 25 +++++++++++++
>  test/app/uuid.result   | 79 ++++++++++++++++++++++++++++++++++++++++++
>  test/app/uuid.test.lua | 29 ++++++++++++++++
>  4 files changed, 134 insertions(+)
> 

<snipped>

> diff --git a/src/lua/uuid.lua b/src/lua/uuid.lua
> index 42016601d..08991cfeb 100644
> --- a/src/lua/uuid.lua
> +++ b/src/lua/uuid.lua

<snipped>

> +local uuid_lt = function(lhs, rhs)
> +    return uuid_cmp(lhs, rhs) < 0
> +end
> +local uuid_le = function(lhs, rhs)
> +    return uuid_cmp(lhs, rhs) <= 0
> +end

Side note: I see no reason to define these oneline functions (you can
simply store an anonymous function right to the metatable), but I see
them everywhere in Tarantool sources, so feel free to ignore this note.

> +

<snipped>

> -- 
> 2.29.0
> 

-- 
Best regards,
IM