docs-v2/content/v2.0/reference/flux/language/_index.md

title	description	menu	weight	v2.0/tags
Flux language specification	Covers the current and future Flux functional data scripting language, which is designed for querying, analyzing, and acting on data.	v2_0_ref name parent Flux specification Flux language	103	flux

The following document specifies the Flux language and query execution.

{{% note %}} This document is a living document and may not represent the current implementation of Flux. Any section that is not currently implemented is commented with a [IMPL#XXX] where XXX is an issue number tracking discussion and progress towards implementation. {{% /note %}}

The Flux language is centered on querying and manipulating time series data.

Notation

The syntax of the language is specified using Extended Backus-Naur Form (EBNF):

Production  = production_name "=" [ Expression ] "." .
Expression  = Alternative { "|" Alternative } .
Alternative = Term { Term } .
Term        = production_name | token [ "…" token ] | Group | Option | Repetition .
Group       = "(" Expression ")" .
Option      = "[" Expression "]" .
Repetition  = "{" Expression "}" .

Productions are expressions constructed from terms and the following operators, in increasing precedence:

|   alternation
()  grouping
[]  option (0 or 1 times)
{}  repetition (0 to n times)

Lower-case production names are used to identify lexical tokens. Non-terminals are in Camel case. Lexical tokens are enclosed in double quotes ("") or back quotes (``).