From ef63fdc533076c6f99ead829dd93c06d639b7833 Mon Sep 17 00:00:00 2001 From: Gabor Pali Date: Tue, 17 Jan 2023 10:54:19 +0100 Subject: docs(mango): match description of `$mod` with reality The remainder argument for the `$mod` operator can be zero, while its documentation suggests otherwise. It actually covers a very realistic use case where divisibility is expressed. Neither related restrictions could be identified in the sources [1] nor MongoDB forbids this [2]. Tests also seem to exercise this specific case [3]. Thanks @iilyak for checking on these. [1] https://github.com/apache/couchdb/blob/adf17140e81d0b74f2b2ecdea48fc4f702832eaf/src/mango/src/mango_selector.erl#L512:L513 [2] https://www.mongodb.com/docs/manual/reference/operator/query/mod/ [3] https://github.com/apache/couchdb/blob/0059b8f90e58e10b199a4b768a06a762d12a30d3/src/mango/test/03-operator-test.py#L58 --- src/docs/src/api/database/find.rst | 4 ++-- src/mango/README.md | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/src/docs/src/api/database/find.rst b/src/docs/src/api/database/find.rst index 2ec5cc646..d1dfe6e65 100644 --- a/src/docs/src/api/database/find.rst +++ b/src/docs/src/api/database/find.rst @@ -704,8 +704,8 @@ operators require the argument to be in a specific JSON format. | | | | document. Non-array fields cannot | | | | | match this condition. | +---------------+-------------+------------+-----------------------------------+ -| Miscellaneous | ``$mod`` | [Divisor, | Divisor and Remainder are both | -| | | Remainder] | positive or negative integers. | +| Miscellaneous | ``$mod`` | [Divisor, | Divisor is a non-zero integer, | +| | | Remainder] | Remainder is any integer. | | | | | Non-integer values result in a | | | | | 404. Matches documents where | | | | | ``field % Divisor == Remainder`` | diff --git a/src/mango/README.md b/src/mango/README.md index 4c4bb60a6..9fa273b15 100644 --- a/src/mango/README.md +++ b/src/mango/README.md @@ -302,7 +302,7 @@ Array related operators Misc related operators -* "$mod" - [Divisor, Remainder], where Divisor and Remainder are both positive integers (ie, greater than 0). Matches documents where (field % Divisor == Remainder) is true. This is false for any non-integer field +* "$mod" - [Divisor, Remainder], where Divisor is a non-zero integer and Remainder is any integer. Matches documents where (field % Divisor == Remainder) is true. This is false for any non-integer field * "$regex" - string, a regular expression pattern to match against the document field. Only matches when the field is a string value and matches the supplied matches -- cgit v1.2.1