Files
linguist/samples/ABNF/toml.abnf
René Schwaiger 6a1423d28f Add support for ABNF
Augmented Backus–Naur form ([ABNF][]) is a metalanguage used to specify
language grammars.

[ABNF]: https://en.wikipedia.org/wiki/Augmented_Backus–Naur_form
2016-11-02 12:52:16 +01:00

191 lines
5.3 KiB
ABNF

; Source: https://github.com/toml-lang/toml
; License: MIT
;; This is an attempt to define TOML in ABNF according to the grammar defined
;; in RFC 4234 (http://www.ietf.org/rfc/rfc4234.txt).
;; TOML
toml = expression *( newline expression )
expression = (
ws /
ws comment /
ws keyval ws [ comment ] /
ws table ws [ comment ]
)
;; Newline
newline = (
%x0A / ; LF
%x0D.0A ; CRLF
)
newlines = 1*newline
;; Whitespace
ws = *(
%x20 / ; Space
%x09 ; Horizontal tab
)
;; Comment
comment-start-symbol = %x23 ; #
non-eol = %x09 / %x20-10FFFF
comment = comment-start-symbol *non-eol
;; Key-Value pairs
keyval-sep = ws %x3D ws ; =
keyval = key keyval-sep val
key = unquoted-key / quoted-key
unquoted-key = 1*( ALPHA / DIGIT / %x2D / %x5F ) ; A-Z / a-z / 0-9 / - / _
quoted-key = quotation-mark 1*basic-char quotation-mark ; See Basic Strings
val = integer / float / string / boolean / date-time / array / inline-table
;; Table
table = std-table / array-table
;; Standard Table
std-table-open = %x5B ws ; [ Left square bracket
std-table-close = ws %x5D ; ] Right square bracket
table-key-sep = ws %x2E ws ; . Period
std-table = std-table-open key *( table-key-sep key) std-table-close
;; Array Table
array-table-open = %x5B.5B ws ; [[ Double left square bracket
array-table-close = ws %x5D.5D ; ]] Double right square bracket
array-table = array-table-open key *( table-key-sep key) array-table-close
;; Integer
integer = [ minus / plus ] int
minus = %x2D ; -
plus = %x2B ; +
digit1-9 = %x31-39 ; 1-9
underscore = %x5F ; _
int = DIGIT / digit1-9 1*( DIGIT / underscore DIGIT )
;; Float
float = integer ( frac / frac exp / exp )
zero-prefixable-int = DIGIT *( DIGIT / underscore DIGIT )
frac = decimal-point zero-prefixable-int
decimal-point = %x2E ; .
exp = e integer
e = %x65 / %x45 ; e E
;; String
string = basic-string / ml-basic-string / literal-string / ml-literal-string
;; Basic String
basic-string = quotation-mark *basic-char quotation-mark
quotation-mark = %x22 ; "
basic-char = basic-unescaped / escaped
escaped = escape ( %x22 / ; " quotation mark U+0022
%x5C / ; \ reverse solidus U+005C
%x2F / ; / solidus U+002F
%x62 / ; b backspace U+0008
%x66 / ; f form feed U+000C
%x6E / ; n line feed U+000A
%x72 / ; r carriage return U+000D
%x74 / ; t tab U+0009
%x75 4HEXDIG / ; uXXXX U+XXXX
%x55 8HEXDIG ) ; UXXXXXXXX U+XXXXXXXX
basic-unescaped = %x20-21 / %x23-5B / %x5D-10FFFF
escape = %x5C ; \
;; Multiline Basic String
ml-basic-string-delim = quotation-mark quotation-mark quotation-mark
ml-basic-string = ml-basic-string-delim ml-basic-body ml-basic-string-delim
ml-basic-body = *( ml-basic-char / newline / ( escape newline ))
ml-basic-char = ml-basic-unescaped / escaped
ml-basic-unescaped = %x20-5B / %x5D-10FFFF
;; Literal String
literal-string = apostraphe *literal-char apostraphe
apostraphe = %x27 ; ' Apostrophe
literal-char = %x09 / %x20-26 / %x28-10FFFF
;; Multiline Literal String
ml-literal-string-delim = apostraphe apostraphe apostraphe
ml-literal-string = ml-literal-string-delim ml-literal-body ml-literal-string-delim
ml-literal-body = *( ml-literal-char / newline )
ml-literal-char = %x09 / %x20-10FFFF
;; Boolean
boolean = true / false
true = %x74.72.75.65 ; true
false = %x66.61.6C.73.65 ; false
;; Datetime (as defined in RFC 3339)
date-fullyear = 4DIGIT
date-month = 2DIGIT ; 01-12
date-mday = 2DIGIT ; 01-28, 01-29, 01-30, 01-31 based on month/year
time-hour = 2DIGIT ; 00-23
time-minute = 2DIGIT ; 00-59
time-second = 2DIGIT ; 00-58, 00-59, 00-60 based on leap second rules
time-secfrac = "." 1*DIGIT
time-numoffset = ( "+" / "-" ) time-hour ":" time-minute
time-offset = "Z" / time-numoffset
partial-time = time-hour ":" time-minute ":" time-second [time-secfrac]
full-date = date-fullyear "-" date-month "-" date-mday
full-time = partial-time time-offset
date-time = full-date "T" full-time
;; Array
array-open = %x5B ws ; [
array-close = ws %x5D ; ]
array = array-open array-values array-close
array-values = [ val [ array-sep ] [ ( comment newlines) / newlines ] /
val array-sep [ ( comment newlines) / newlines ] array-values ]
array-sep = ws %x2C ws ; , Comma
;; Inline Table
inline-table-open = %x7B ws ; {
inline-table-close = ws %x7D ; }
inline-table-sep = ws %x2C ws ; , Comma
inline-table = inline-table-open inline-table-keyvals inline-table-close
inline-table-keyvals = [ inline-table-keyvals-non-empty ]
inline-table-keyvals-non-empty = key keyval-sep val /
key keyval-sep val inline-table-sep inline-table-keyvals-non-empty
;; Built-in ABNF terms, reproduced here for clarity
; ALPHA = %x41-5A / %x61-7A ; A-Z / a-z
; DIGIT = %x30-39 ; 0-9
; HEXDIG = DIGIT / "A" / "B" / "C" / "D" / "E" / "F"