TypeQL Rust prototype

[dmitrii-ubskii]

What is the goal of this PR?

We implement a subset of the TypeQL parser in Rust. The scope encompasses basic, i.e. non-aggregate, match queries like:

match
$brando "Marl B" isa name;
(actor: $brando, $char, movie: $movie);
$movie has title $title,
    has release-date 2020-05-07T00:00;
get $char, $title; sort $title;

What are the changes implemented in this PR?

Implemented the data structures with corresponding builder functions and parser visitors for the following constructs:

• match query;
• generic conjunction;
• thing variable constraints:
  • isa X;
  • has X;
  • attribute value constraints: $x = $y or $x 123;
  • relations: $r(role: $x, ...) isa relation_type;
• type variable constraints:
  • type T;
  • sub T;
  • relates R;
  • plays R;
  • owns T;
• match query modifiers:
  • get $x;
  • sort $x;
  • limit N;
  • offset N.

[grabl]

PR Review Checklist

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Code

• [x] Packages, classes, and methods have a single domain of responsibility.
• [x] Packages, classes, and methods are grouped into cohesive and consistent domain model.
• [x] The code is canonical and the minimum required to achieve the goal.
• [x] Modules, libraries, and APIs are easy to use, robust (foolproof and not errorprone), and tested.
• [x] Logic and naming has clear narrative that communicates the accurate intent and responsibility of each module (e.g. method, class, etc.).
• [x] The code is algorithmically efficient and scalable for the whole application.

Architecture

• [x] Any required refactoring is completed, and the architecture does not introduce technical debt incidentally.
• [x] Any required build and release automations are updated and/or implemented.
• [x] Any new components follows a consistent style with respect to the pre-existing codebase.
• [x] The architecture intuitively reflects the application domain, and is easy to understand.
• [x] The architecture has a well-defined hierarchy of encapsulated components.
• [x] The architecture is extensible and scalable.