inaccessible is fatal by default
lexeme default = latm => 1

:start       ::= PlistFile
PlistFile    ::= VersionData Ows GlobalPlists
VersionData  ::= 'Version' WS FLOAT Ows ';'
GlobalPlists ::= GlobalPlist+
GlobalPlist  ::= GLOBAL_PL_DECLARE WS PL_NAME Ows OptPlOptions Ows '{' Ows OptEmbeddedBase Ows Nodes '}' Ows

OptPlOptions ::= Option*
Option       ::= '[' Ows OPTION_DATA Ows ']' Ows

OptEmbeddedBase ::= EmbeddedBase*
EmbeddedBase    ::= '#' Ows 'base' Ows '=' Ows BaseNumbers
BaseNumbers     ::= BASE_NUMBER+ separator => COMMA

Nodes ::= Node+
Node  ::= Pattern | COMMENT | GlobalPlist || ReferencePlist

Pattern      ::= PAT_DECLARE WS PAT_NAME Ows OptPatOption ';' Ows OptTagStr Ows
OptPatOption ::= Option
OptPatOption ::=
OptTagStr    ::= TagStr
OptTagStr    ::=
TagStr       ::= '#' Ows TagList Ows '#'
TagList      ::= TAG* separator => COMMA

ReferencePlist ::= 'PList' WS RefPlName Ows ';' Ows
RefPlName      ::= OptRefFile PL_NAME
OptRefFile     ::= RefFile*
RefFile        ::= FILE_NAME ':'

Ows  ::= WS # a lexeme cannot have zero length,
Ows  ::=    # so optional whitespace must be a high-level grammar feature
WS                ~ ws
COMMA             ~ ','
COMMENT           ~ '#' comment_chars [\n]
                  | '#' comment_chars [\n] ws
FLOAT             ~ int | int '.' int
BASE_NUMBER       ~ int
PL_NAME           ~ identifier
TAG               ~ identifier
PAT_NAME          ~ identifier
PAT_DECLARE       ~ 'Pat' | 'Pattern'
GLOBAL_PL_DECLARE ~ 'GlobalPList' | 'LocalPList' | 'PatternList'
FILE_NAME         ~ [\w.]+
OPTION_DATA       ~ [\w \.,]*

ws            ~ [\s]+
identifier    ~ [\w]+
comment_chars ~ [^\n]+
int           ~ [\d]+