term     ::= ( text | expr | pipeline ) ','? ;

pipeline ::= container?  trail+ ;

trail    ::= var | '[' term ']' ;

container::= '[' term* ']'
           |  '{' ( dot_name (':' text | '=' term )
                  | other+ ','?
                  )* '}' ;

var      ::= (':'+ | '.'+) name ( '(' term* ')' )? ;
name     ::= \w+ ;
dot_name ::= [\w\.]+ ;

expr     ::= '=' text ;
text     ::= word ( group word? )* ; -- group で始まるのは、container.

group    ::= [\(\[\{] ( text | ',' )* [\}\]\)]

word     ::= [\w\$\-\+\*/%<>] other* ;
other    ::= [\w\$\-\+\*/%<>:\.!=] ;