[Feature Request]: FINAL search engine features for 9.5

[python357-1]

Checklist

• I am using an up-to-date version.
• I have read the documentation.
• I have searched existing issues.

Description

this issue describes the current consensus on what features the search engine will have for the 9.5 release.

REQUIRED for 9.5:

new queries - a definition and implementation of a "query language" which can be converted to SQL queries to be made against the database

• Boolean operators: AND, OR, and NOT operators for said queries
• tag, tag_id, mediatype, filetype, path, and special queries: types of queries to be run against entries/tags in the database

query	description	allowed values	example
tag	searches by tag name, with an optional "disambiguation" syntax that specifies which tag you are looking for, if there are multiple matches	string	tag: Mario tag: Mario[parent=nintendo]
tag_id	searches by the internal ID of a tag	int	tag_id: 1001
mediatype	searches by name property of MediaCategories (will eventually use the translated name)	string	mediatype: video
filetype	searches by the file extension	string	filetype: jpg
path	searches by complete path of files. allows globs	string	path: folder/*
special	searches by special metadata of entries	"untagged" "unlinked"	special: untagged

• field content search: TODO
• sortable results (possibly in a different issue/PR)

STRETCH GOALS for 9.5

• new search UI (will be in a separate issue/PR)
• HAS query (waiting on composition tags to be implemented)

[Computerdores]

I am interested in working on a parser for this. Feedback on my current WIP grammar would be nice:

ANDList        = ORList ( ["AND"] ORList )* ;
ORList         = Term ( "OR", Term )* ;
Term           = Constraint | "(", ANDList, ")" ;

Constraint     = [ConstraintType, ":"], Literal, "[", PropertyList, "]" ;

ConstraintType = "tag" | "mediaType" ; (* not a complete list *)
PropertyList   = Property, (",", Property)* ;
Property       = ULITERAL, "=", Literal ;
Literal        = ULITERAL | QLITERAL ;

Notes:

• QLITERAL means a quoted literal (e.g.: "test 'hello' end", 'test "hello" end', 'What\'s this, \ escaping?')
• ULITERAL means an unquoted literal (like the value of this property: test=true)

[python357-1]

Looks pretty good to me! I'm just curious, is the reason for ANDLists and ORLists being separate things for which one takes precedence over the other? If so, does the current grammar make ANDs take precedence over ORs? That would be ideal

[Computerdores]

Looks pretty good to me!

Thanks! I am also much more happy with this that with my previous version. This is much simpler and should be easier to parse.

is the reason for ANDLists and ORLists being separate things for which one takes precedence over the other?

Yes!

does the current grammar make ANDs take precedence over ORs? That would be ideal

No it does not, OR would be evaluated first here. AND taking precedence over OR would be more intuitive for me too, however iirc @CyanVoxel suggested this somewhere in the discussion on the discord and I generally don't care too much about it.

(Cyan, If I am not supposed to ping you let me know, I asked on the discord before, but a big discussion broke out right after so I believe you missed it)

[CyanVoxel]

No it does not, OR would be evaluated first here. AND taking precedence over OR would be more intuitive for me too, however iirc @CyanVoxel suggested this somewhere in the discussion on the discord and I generally don't care too much about it.

Unless it was a looooong time ago, I don't remember preferring OR over AND; the opposite seems more intuitive to me as well. I know I brought up a preference for implicit AND when no operator is given, but I'm not sure if that's related here.

(Cyan, If I am not supposed to ping you let me know, I asked on the discord before, but a big discussion broke out right after so I believe you missed it)

It's alright to ping me, I miss too much stuff to warrant not being pinged 🙃

[Computerdores]

No it does not, OR would be evaluated first here. AND taking precedence over OR would be more intuitive for me too, however iirc @CyanVoxel suggested this somewhere in the discussion on the discord and I generally don't care too much about it.

Unless it was a looooong time ago, I don't remember preferring OR over AND; the opposite seems more intuitive to me as well. I know I brought up a preference for implicit AND when no operator is given, but I'm not sure if that's related here.

Alright nvm then. I have a first go at the parser almost done (still with OR preference though) so I might open a Draft PR in the next days.

[Computerdores]

Updated Grammar (AND now binds stronger than OR as is normal):

ORList         = ANDList ( "OR", ANDList)* ;
ANDList        = Term ( ["AND"] Term )* ;
Term           = Constraint | "(", ORList, ")" ;

Constraint     = [ConstraintType, ":"], Literal, "[", PropertyList, "]" ;

ConstraintType = "tag" | "mediaType" ; (* not a complete list *)
PropertyList   = Property, (",", Property)* ;
Property       = ULITERAL, "=", Literal ;
Literal        = ULITERAL | QLITERAL ;

Notes:

• QLITERAL means a quoted literal (e.g.: "test 'hello' end", 'test "hello" end', 'What\'s this, \ escaping?')
• ULITERAL means an unquoted literal (like the value of this property: test=true)

[Computerdores]

With this proposal we are currently missing a way to search for untagged files.

My idea on how to fix this would be the following syntax: special:untagged.

The advantage of this is that this could also be used to add other special criteria like e.g. special:unlinked to search for unlinked entries. And it would nicely integrate into the grammar and the existing code base on #606

[CyanVoxel]

With this proposal we are currently missing a way to search for untagged files.

My idea on how to fix this would be the following syntax: special:untagged.

The advantage of this is that this could also be used to add other special criteria like e.g. special:unlinked to search for unlinked entries. And it would nicely integrate into the grammar and the existing code base on #606

I like this approach. Simply typing "empty" or "untagged" was nice in 9.4, but realistically it shadowed any potential tags with those names. This new approach avoids that issue while also making sure it plays nicely with the grammar 👍

[python357-1]

Added a table for all current search queries. Let me know if anything needs to be changed