[Cod-bugs] Authors matching in Optimade API

[Andrius Merkys]

Dear Mehmet,

On 2025-11-17 17:03, Mehmet Giritli - STFC UKRI wrote:
> We are looking forward to have exact matches in COD. Thank you so much!

Great - we will look into implementing these queries to the letter of 
the specification.

> Regarding "HAS CONTAINS", this does not seem to work with the Lark 
> validator we have. In our system, we use a query validator to check for 
> valid optimade filters. This is done by the Lark language interpreter 
> which the optimade library uses. It gives an error when this combination 
> is used. Here is an example:
> 
> 
>     Unable to parse filter ( _psdi_authors HAS CONTAINS " Day " ). Lark
>     traceback:
>     No terminal matches 'C' in the current parser context, at line 1 col 21
> 
>     ( _psdi_authors HAS CONTAINS " Day " )
>                          ^
>     Expected one of:
>              * SIGNED_INT
>              * OPERATOR
>              * FALSE
>              * SIGNED_FLOAT
>              * ESCAPED_STRING
>              * TRUE
>              * ALL
>              * IDENTIFIER
>              * ANY
>              * ONLY
> 
> May I ask you, whenever you get around to it, to double check with 
> Optimade spec if this is allowed please? Unless it is a legal Optimade 
> query, we will not be able to use it. Moreover, Matthew Evans has done a 
> private API for us and CONTAINS operator in the way I showed above is 
> how we use it (e.g., author.names CONTAINS "..."). I might be wrong, but 
> may be the "authors" is the list here and "authors.name" is actually a 
> string? I think Mattew Evans is the best person to answer that, I 
> haven't looked to the Optimade spec for a while now 🙂

Queries like 'HAS CONTAINS' were only made possible since the OPTIMADE 
specification release v1.2.0 last year 
(https://github.com/Materials-Consortia/OPTIMADE/pull/415). Prior to 
v1.2.0 they were not supported. I have a hunch that Lark grammar has not 
been updated since v1.2.0. We may pull Matthew to the discussion to 
check the status of the grammar.

Best wishes,
Andrius

-- 
Andrius Merkys
Vilnius University Institute of Biotechnology, Saulėtekio al. 7
LT-10257 Vilnius, Lithuania

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