// BNF notation:
// <> Defined element
// = is defined as
// | Exclusive OR
// {} Group, one element is required
// [] Optional, can be omitted
// ... Previous element(s) may be repeated

// Message elements
// [:]<Header>[<Space><Argument>[<Comma>[<Space>]<Argument>]...]

// Agrument types
// <NR1> Signed integer value
// <NR2> Floating point value
// <NR3> Floating point value with exponent
// <Nrf> Mixed format, any of <NR1>, <NR2>, <NR3>
// <Nrf+> Mixed format, any of <Nrf>, MIN, MAX or DEF
// <bin> Signed or unsigned integer in binary format
// <Bool> 0|1|ON|OFF
// <QString> Quoted with single (') or double quotes (")
// <NZDig> Non-zero digit character 1-9
// <Dig> Digit character 0-9
// <DChar> Character with hex equivalent 00-FF (0-255 decimal)
// <Block> {#<NZDig><Dig>[<Dig>...][<DChar>...]|#0[<DChar>...]<terminator>}

// Mnemonics
// CH<x> channel specifier, <x> is 1 through 4
// CURSOR<x> cursor selector, <x> is 1 or 2

const nr1 = `[+-]?\d+`
const nr2 = `[+-]?(?:\d+\.?\d*|\d*\.\d+)`
const nr3 = `${nr2}(?:[eE]${nr2})?`
const NR1 = new RegExp(`(${nr1})`)
const NR2 = new RegExp(`(${nr2})`)
const NR3 = new RegExp(`(${nr3})`)

const nfr = `${nr1}|${nr2}|${nr3}`
const nfrp = `${nfr}|MIN|MAX|DEF`
const Nfr = new RegExp(`(${nfr})`)
const Nfrp = new RegExp(`(${nfrp})`)

const bool = `0|1|ON|OFF`
const Bool = new RegExp(`(${bool})`)

const qString = `(?:["'])(?:(?:\\{2})*|(?:.*?[^\\](?:\\{2})*))\1`
const QString = new RegExp(`(${qString})`)

const dig = `\d`
const nzdig = `[1-9]`
const dchar = `[\\x00-\\xFF]`
const Dig = new RegExp(`(${dig})`)
const ZNDig = new RegExp(`(${nzdig})`)
const DChar = new RegExp(`(${dchar})`)

const block = `#${nzdig}(?:${dig})+(?:${dchar})*|#0(?:${dchar})*`
const Block = new RegExp(`(${block})`)

const header = `v`
const Header = new RegExp(`(${header})`)