doonv/bevy_dev_console

Entity Queries

doonv opened this issue · 10 comments

doonv commented

Currently, you cannot access entities properties. In order to access entities properties we will need entity queries. Entity queries will be a built-in parser feature that will allow you to query the entities you choose and modify them.

Design

Todo list for the design of the entity queries.

  • Design the syntax.
    • Id queries
      • This should probably be just the entity id, very simple.
    • Single queries
      • Queries for a single entity and provides access to all of their components.
    • For-each queries
      • Queries for a group of entities based on their components and executes a command on each of them.
  • Figure out how to create dynamic reflection-based queries at runtime.

Implementation

After the design has been finished, we can start the implementation.

  • Parsing
    • Id Queries
    • Single queries
    • For-each queries
  • Execution
    • Id Queries
    • Single queries
    • For-each queries
nicopap commented

I've designed a DSL for querying here https://github.com/nicopap/bevy_mod_dynamic_query/tree/main/examples/query_interpreter#query-grammar if you need some inspiration. You can always re-use the bevy type DSL though.

doonv commented

That looks cool, How will I go from the regular built-in parser to the DSL though?

nicopap commented

I mean, you write a grammar that supports the rust syntax. The full parser for both syntax is defined here https://github.com/nicopap/bevy_mod_dynamic_query/blob/149b5d4a5a3611373b99b83bc9075cbd7d03b01e/examples/query_interpreter/src/query_parser.rs. Similarly to video game FX, no need to support all the intricacies of the rust syntax, it just need to look like it :P

doonv commented

I meant something like $( insert query here ).MyProperty = 5.4. The $( ... ) transitions from the built-in parser's language to the Querying DSL. I kinda like the $( ... ) syntax what do you think?

nicopap commented

Always can use a keyword that it a rust keyword, so that you are sure to avoid overlapping with pre-existing field names. For example for ( bindings ) in <query> { … }. Or terser yet: for(<query>).… (yield?). I also like the functional style, swapping for with map.

doonv commented

@nicopap I'd like to use your bevy_mod_dynamic_query library for this, and I have a few issues with it. but it looks like issues are disabled. Can you re-enable them?

nicopap commented

Issues are now re-enabled on bevy_mod_dynamic_query.

doonv commented

Thanks!

doonv commented

Ah turns out my issue is actually not a problem.

doonv commented

This is currently blocked by either of the following:

  • bevy_mod_dynamic_query isnt updated for Bevy 0.12.
  • Bevy 0.13 has dynamic querying, but it isn't released yet.