metadesk/tests/grammar.md

/* MetaDesk grammar with semantic annotations *

• Each line represents a BNF-esque production:

•  symbol : rule_1 | ... | rule_n
  

• • Pipe signs indicate mutually exclusive alternatives
• • Square quotes denote optional rules
• • Character literals are terminal productions
• • Tags indicate which way the productions attach to the generated tree (@child, @sibling, @tag)
• and miscellaneous semantics (@fill, @markup) */

//// Arbitrarily deep tree, possibly empty // file : [@child set] // set : '{' [@child set] '}' | set [separator @sibling set] // separator : ' ' | '\n' | ',' | ';'

//// Labeled leaves // file : [@child set] // set : @fill 'A' | '{' [@child set] '}' | set [separator @sibling set] // separator : ' ' | '\n' | ',' | ';'

//// Labeled internal nodes // file : [@child set] // set : @fill 'A' | [@fill 'A' ':'] scoped_set | set [separator @sibling set] // separator : ' ' | '\n' | ',' | ';' // scoped_set : '{' [@child set] '}'

//// Unscoped tests (feels like there should be an easier way to express this) // file : general_set // general_set : { [@child set] | [@child uns_set] } // set : @fill 'A' | set [sep1 @sibling set] | scoped_set | uns_set sep2 @sibling set // uns_set : @fill 'A' [uns_set_tail] // uns_set_tail : ':' @child uns_set | ' ' @sibling uns_set | ':' scoped_set | ' ' @sibling scoped_set // scoped_set : '{' general_set '}' // sep1 : ' ' | '\n' | ',' | ';' // sep2 : '\n'| ',' | ';'

//// Tags // file : general_set // general_set : { [@child set] | [@child uns_set] } // set : {[tag_list] untagged_set} // uns_set : {[tag_list] untagged_uns_set} // tag_list : '@' @tag tag ' ' [tag_list] // tag : @fill 'T'['(' general_set ')'] // untagged_set : @fill 'A' | set [sep1 @sibling set] | scoped_set | uns_set sep2 @sibling set // untagged_uns_set: @fill 'A' [uns_set_tail] // uns_set_tail : ':' @child uns_set | ' ' @sibling uns_set | ':' scoped_set | ' ' @sibling scoped_set // scoped_set : '{' general_set '}' // sep1 : ' ' | '\n' | ',' | ';' // sep2 : '\n'| ',' | ';'

//// Alternative scope markers // file : general_set // general_set : { [@child set] | [@child uns_set] } // set : {[tag_list] untagged_set} // uns_set : {[tag_list] untagged_uns_set} // tag_list : '@' @tag tag ' ' [tag_list] // tag : @fill 'T'['(' general_set ')'] // untagged_set : @fill 'A' | set [sep1 @sibling set] | scoped_set | uns_set sep2 @sibling set // untagged_uns_set: @fill 'A' [uns_set_tail] // uns_set_tail : ':' @child uns_set | ' ' @sibling uns_set | ':' scoped_set | ' ' @sibling scoped_set // scoped_set : '{' general_set '}' | alt_scope_beg general_set alt_scope_end // alt_scope_beg : '(' | '[' // alt_scope_end : ')' | ']' // sep1 : ' ' | '\n' | ',' | ';' // sep2 : '\n'| ',' | ';'

//// Identifiers // file : general_set // general_set : { [@child set] | [@child uns_set] } // set : {[tag_list] untagged_set} // uns_set : {[tag_list] untagged_uns_set} // tag_list : '@' @tag tag ' ' [tag_list] // tag : @fill id['(' general_set ')'] // untagged_set : @fill 'A' | set [sep1 @sibling set] | scoped_set | uns_set sep2 @sibling set // untagged_uns_set: @fill 'A' [uns_set_tail] // uns_set_tail : ':' @child uns_set | ' ' @sibling uns_set | ':' scoped_set | ' ' @sibling scoped_set // scoped_set : '{' general_set '}' | alt_scope_beg general_set alt_scope_end // alt_scope_beg : '(' | '[' // alt_scope_end : ')' | ']' // sep1 : ' ' | '\n' | ',' | ';' // sep2 : '\n'| ',' | ';' // id : alpha [alphanumeric] | '' [alphanumeric] // alphanumeric : alpha [alphanumeric] | digit [alphanumeric] | '' [alphanumeric] // alpha : lowercase | uppercase // lowercase : 'a'|'b'|'c'|'d'|'e'|'f'|'g'|'h'|'i'|'j'|'k'|'l'|'m'|'n'|'o'|'p'|'q'|'r'|'s'|'t'|'u'|'v'|'w'|'z'|'y'|'z' // uppercase : 'A'|'B'|'C'|'D'|'E'|'F'|'G'|'H'|'I'|'J'|'K'|'L'|'M'|'N'|'O'|'P'|'Q'|'R'|'S'|'T'|'U'|'V'|'W'|'Z'|'Y'|'Z' // digit : '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'

//// General labels file : general_set general_set : { [@child set] | [@child uns_set] } set : {[tag_list] untagged_set} uns_set : {[tag_list] untagged_uns_set} tag_list : '@' @tag tag ' ' [tag_list] tag : @fill id['(' general_set ')'] untagged_set : @fill label | set [sep1 @sibling set] | scoped_set | uns_set sep2 @sibling set untagged_uns_set: @fill label [uns_set_tail] uns_set_tail : ':' @child uns_set | ' ' @sibling uns_set | ':' scoped_set | ' ' @sibling scoped_set scoped_set : '{' general_set '}' | alt_scope_beg general_set alt_scope_end alt_scope_beg : '(' | '[' alt_scope_end : ')' | ']' sep1 : ' ' | '\n' | ',' | ';' sep2 : '\n'| ',' | ';' id : alpha [alphanumeric] | '' [alphanumeric] alphanumeric : alpha [alphanumeric] | digit [alphanumeric] | '' [alphanumeric] alpha : lowercase | uppercase lowercase : 'a'|'b'|'c'|'d'|'e'|'f'|'g'|'h'|'i'|'j'|'k'|'l'|'m'|'n'|'o'|'p'|'q'|'r'|'s'|'t'|'u'|'v'|'w'|'z'|'y'|'z' uppercase : 'A'|'B'|'C'|'D'|'E'|'F'|'G'|'H'|'I'|'J'|'K'|'L'|'M'|'N'|'O'|'P'|'Q'|'R'|'S'|'T'|'U'|'V'|'W'|'Z'|'Y'|'Z' digit : '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9' label : id | integer_literal | char_literal | string_literal | symbol_label integer_literal : { ['-'] natural_literal } natural_literal : digit [natural_literal] char_literal : @markup ''' [char_literal_items] @markup ''' char_literal_items : char_literal_item [char_literal_items] char_literal_item : ascii_no_backslash_no_quotes | '"' | '\' ascii ascii : ascii_no_backslash_no_quotes | ''' | '"' | '' | '\\' ascii_no_backslash_no_quotes : digit | alpha | symbol_no_backslash_no_quotes | ' ' symbol_no_backslash_no_quotes : symbol_no_backslash_no_quotes_1 | symbol_no_backslash_no_quotes_2 symbol_no_backslash_no_quotes_1 : '!'|'#'|'$'|'%'|'&'|'('|')'|'*'|'+'|','|'-'|'.'|'/'|':' symbol_no_backslash_no_quotes_2 : ';'|'<'|'='|'>'|'?'|'@'|'['|']'|'^'|'_'|'{'|'|'|'}'|'~' string_literal : @markup '"' [string_literal_items] @markup '"' | @markup '' [string_literal_items] @markup '`' string_literal_items : string_literal_item [string_literal_items] string_literal_item : ascii_no_backslash_no_quotes | ''' | '\' ascii symbol_label : '~'|'!'|'%'|'^'|'&'|'*'|'+'|'-'|'/'|'|'|'<'|'>'|'$'|'='|'.'|'?'|'$'