https://github.com/mbuczko/metaql

PromQL alike query language
https://github.com/mbuczko/metaql

Last synced: 15 days ago
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PromQL alike query language

• Host: GitHub
• URL: https://github.com/mbuczko/metaql
• Owner: mbuczko
• Created: 2023-02-17T21:05:14.000Z (almost 2 years ago)
• Default Branch: master
• Last Pushed: 2024-03-07T20:17:30.000Z (10 months ago)
• Last Synced: 2024-03-07T21:28:31.893Z (10 months ago)
• Language: Rust
• Size: 105 KB
• Stars: 0
• Watchers: 2
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md

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README

        
This crate is to parse a simple query language, similar to one used by [Prometheus](https://prometheus.io/docs/prometheus/latest/querying/basics/).

Grammar considered here comes down to:

``` antlr

query    ->  filter range?

filter   ->  CURLY_OPEN group (OR group)* CURLY_CLOSE

group    ->  matcher (COMMA matcher)*

matcher  ->  PATH op value

op       ->  '!'? ( EQ | CONTAINS )

value    ->  scalar | array

scalar   ->  STRING | BOOL | numeric

numeric  ->  INTEGER | FLOAT

array    ->  SQARE_OPEN value ( COMMA value )* SQARE_CLOSE

range    ->  SQARE_OPEN duration SQUARE_CLOSE

duration ->  INTEGER unit

unit     ->  "ms" | "s" | "m" | "h" | "d" | "w" | "mo" | "y"

```

which allows to define queries, as simple as:

```

{ meta.tags ~ "vacation" }

```

or more complicated, like:

```

{ meta.tags ~ "vacation", status = "completed" }

{ meta.tags ~ "vacation", status ~ ["completed", "in-progress"] }

{ meta.focal_length = "35mm" } [10d]

{ meta.focal_length = "35mm" | meta.camera = "pentax" } 

{ meta.tags ~ "vacation", nickname = "alice", meta.focal_length = 18.5 | meta.camera = "pentax"} [10d]

```

Futhermore, AST can be auto-transformed into corresponding WHERE conditions of SQL query.

Note, conditions are tightly coupled with Postgres notation for now. For example, nested paths like `meta.focal_length` are assumed to be a valid paths within JSON objects, and as such are turned into postgres-specific JSON queries (`meta->>'focal_length` in this case).

WIP.