Crate promql

This crate allows one to parse PromQL query into some AST.

See official documentation for query syntax description.

Example

use promql::*;

let opts = ParserOptions::new()
	.allow_dots(false)
	.build();

// query can also be `&str`
let query: &[u8] = br#"
	sum(1 - something_used{env="production"} / something_total) by (instance)
	and ignoring (instance)
	sum(rate(some_queries{instance=~"localhost\\d+"} [5m])) > 100
"#;
let ast = parse(query, &opts).unwrap(); // or show user that their query is invalid

// now we can look for all sorts of things

// AST can represent an operator
if let Node::Operator { op: Op::And(op_mod), args } = ast {
	// operators can have modifiers
	assert_eq!(op_mod, Some(OpMod {
		action: OpModAction::Ignore,
		labels: vec!["instance".to_string()],
		group: None,
	}));

	// aggregation functions like sum are represented as functions with optional modifiers (`by (label1, …)`/`without (…)`)
	if let Node::Function { ref name, ref aggregation, ref args } = args[0] {
		assert_eq!(*name, "sum".to_string());
		assert_eq!(*aggregation, Some(AggregationMod {
			action: AggregationAction::By,
			labels: vec!["instance".to_string()],
		}));

		// …
	}
} else {
	panic!("top operator is not an 'and'");
}

Types

This parser emits Vec<u8> for most string literals because PromQL, like Go, allows raw byte sequences to be included in the string literals (e.g. {omg='∞'} is equivalent to both {omg='\u221e'} and {omg='\xe2\x88\x9e'}).

Structs

AggregationMod

LabelMatch

Single label filter.

OpGroupMod

Vector grouping operator modifier (group_left(…)/group_right(…)).

OpMod

Vector matching operator modifier (on (…)/ignoring (…)).

ParserOptions

Options that allow or disallow certain query language features.

ParserOptionsBuilder

A builder for ParserOptions.

Vector

This struct represents both instant and range vectors.

Enums

AggregationAction

LabelMatchOp

Label filter operators.

Node

AST node.

Op

PromQL operators

OpGroupSide

OpModAction

Functions

parse

Parse expression string into an AST.