[grammar test] Cleaner grammar.

tests/grammar.md

@@ -9,148 +9,20 @@
  *   and miscellaneous semantics (@fill, @markup)
  */
 
-//// Arbitrarily deep tree, possibly empty
+//// A bunch of common definitions
-// file            : [@child set]
+separator           : ' ' | unscoped_separator
-// set             : '{' [@child set] '}' | set [separator @sibling set]
+unscoped_separator  : '\n'| ',' | ';'
-// separator       : ' ' | '\n' | ',' | ';'
+alt_scope_beg       : '(' | '['
-
+alt_scope_end       : ')' | ']'
-//// Labeled leaves
+id                  : alpha [alphanumeric] | '_' [alphanumeric]
-// file            : [@child set]
+alphanumeric        : alpha [alphanumeric] | digit [alphanumeric] | '_' [alphanumeric]
-// set             : @fill 'A' | '{' [@child set] '}' | set [separator @sibling set]
+alpha               : lowercase | uppercase
-// separator       : ' ' | '\n' | ',' | ';'
+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'
-//// Labeled internal nodes
+digit               : '0'|'1'|'2'|'3'|'4'|'5'|'6'|'7'|'8'|'9'
-// file            : [@child set]
+label               : id | integer_literal | char_literal | string_literal | symbol_label
-// set             : @fill 'A' | [@fill 'A' ':'] scoped_set | set [separator @sibling set]
+integer_literal     : { ['-'] natural_literal }
-// separator       : ' ' | '\n' | ',' | ';'
+natural_literal     : digit [natural_literal]
-// 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 | untagged_set [sep1 @sibling set] | scoped_set | untagged_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 : '!'|'#'|'$'|'%'|'&'|'('|')'|'*'|'+'|','|'-'|'.'|'/'|':'
-//symbol_no_backslash_no_quotes_2 : ';'|'<'|'='|'>'|'?'|'@'|'['|']'|'^'|'_'|'{'|'|'|'}'|'~'
-//string_literal                  : @markup '"' [string_literal_items] @markup '"' | @markup '`' [string_literal_items] @markup '`'
-//string_literal_items            : string_literal_item [string_literal_items]
-//string_literal_item             : ascii_no_backslash_no_quotes | '\'' | '\\' ascii
-//symbol_label                    : '~'|'!'|'%'|'^'|'&'|'*'|'+'|'-'|'/'|'|'|'<'|'>'|'$'|'='|'.'|'?'|'$'
-
-//// Comments before
-file            : general_set
-general_set     : { [@child set] | [@child uns_set] }
-set             : {[tag_list] ['\n' @pre_comment pre_comment] untagged_set}
-pre_comment     : '/' '/' [' '] [@fill c_code_content] '\n' | '/' '*' [@fill c_code_content] '*' '/'
-c_code_content  : 'c''o''m''m''e''n''t' // TODO: Arbitrary strings, including C-style comments, as long as /* */ pairs are balanced
-cpp_code_content: 'c''o''m''m''e''n''t' // TODO: Arbitrary strings that don't start with space
-uns_set         : {[tag_list] untagged_uns_set}
-tag_list        : '@' @tag tag ' ' [tag_list]
-tag             : @fill id['(' general_set ')']
-untagged_set    : @fill label | untagged_set [sep1 @sibling set] | scoped_set | untagged_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
@@ -163,3 +35,90 @@ string_literal                  : @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                    : '~'|'!'|'%'|'^'|'&'|'*'|'+'|'-'|'/'|'|'|'<'|'>'|'$'|'='|'.'|'?'|'$'
+
+//// Arbitrarily deep tree, possibly empty
+// file                : [@child set_list]
+// set_list            : '{' [@child set_list] '}' [separator @sibling set_list]
+
+//// Labeled leaves
+// file            : [@child set_list]
+// set_list        : set [separator @sibling set_list]
+// set             : @fill 'A' | '{' [@child set_list] '}'
+
+//// Labeled internal nodes
+// file            : [@child set_list]
+// set_list        : set [separator @sibling set_list]
+// set             : @fill 'A' | [@fill 'A' ':'] '{' [@child set_list] '}'
+
+//// Unscoped sets
+// file                : [@child set_list]
+// set_list            : scoped_set [separator @sibling set_list] | unscoped_set [unscoped_separator @sibling set_list]
+// scoped_set          : '{' [@child set_list] '}'
+// unscoped_set        : @fill 'A' [unscoped_set_tail]
+// unscoped_set_tail   : ':' @child unscoped_set | ' ' @sibling unscoped_set | ':' scoped_set |' ' @sibling scoped_set
+
+//// Tags
+// file                : [@child set_list]
+// set_list            : scoped_set [separator @sibling set_list] | unscoped_set [unscoped_separator @sibling set_list]
+// scoped_set          : {[tag_list] '{' [@child set_list] '}'}
+// unscoped_set        : {[tag_list] @fill 'A' [unscoped_set_tail]}
+// tag_list            : '@' @tag tag ' ' [tag_list]
+// tag                 : @fill 'T'['(' [@child set_list] ')']
+// // unscoped_set_tail   : ':' @child unscoped_set | ' ' @sibling unscoped_set | ':' @child scoped_set | ' ' @sibling scoped_set
+// unscoped_set_tail   : {':' @child unscoped_set | ' ' @sibling unscoped_set | set_tail_hack | ' ' @sibling scoped_set}
+//                       // NOTE(mal): Ideally the set_tail_hack should be captured by the simpler
+//                       //            ':' @child scoped_set
+//                       //            but there's a quirk in the grammar. 
+//                       //            In "A:{}", A has no children but in "A:@T{}", it has one tagged children, 
+//                       //            which means that *the presence of tags* introduces the child
+// set_tail_hack       : ':' [@child tag_list] '{' '}' | ':' @child [tag_list] '{' @child set_list '}'
+
+//// Alternative scope markers
+// file                : [@child set_list]
+// set_list            : scoped_set [separator @sibling set_list] | unscoped_set [unscoped_separator @sibling set_list]
+// scoped_set          : {[tag_list] untagged_scoped_set}
+// untagged_scoped_set : '{' [@child set_list] '}' | alt_scope_beg [@child set_list] alt_scope_end
+// unscoped_set        : {[tag_list] @fill 'A' [unscoped_set_tail]}
+// tag_list            : '@' @tag tag ' ' [tag_list]
+// tag                 : @fill 'T'['(' [@child set_list] ')']
+// unscoped_set_tail   : {':' @child unscoped_set | ' ' @sibling unscoped_set | set_tail_hack | ' ' @sibling scoped_set}
+// set_tail_hack       : {':' [@child tag_list] '{' '}' | 
+//                        ':' @child [tag_list] '{' @child set_list '}' | 
+//                        ':' [@child tag_list] alt_scope_beg alt_scope_end | 
+//                        ':' @child [tag_list] alt_scope_beg @child set_list alt_scope_end
+//                       }
+
+//// General tags and labels
+file                : [@child set_list]
+set_list            : scoped_set [separator @sibling set_list] | unscoped_set [unscoped_separator @sibling set_list]
+scoped_set          : {[tag_list] untagged_scoped_set}
+untagged_scoped_set : '{' [@child set_list] '}' | alt_scope_beg [@child set_list] alt_scope_end
+unscoped_set        : {[tag_list] @fill label [unscoped_set_tail]}
+tag_list            : '@' @tag tag ' ' [tag_list]
+tag                 : @fill id['(' [@child set_list] ')']
+unscoped_set_tail   : {':' @child unscoped_set | ' ' @sibling unscoped_set | set_tail_hack | ' ' @sibling scoped_set}
+set_tail_hack       : {':' [@child tag_list] '{' '}' | 
+                       ':' @child [tag_list] '{' @child set_list '}' | 
+                       ':' [@child tag_list] alt_scope_beg alt_scope_end | 
+                       ':' @child [tag_list] alt_scope_beg @child set_list alt_scope_end
+                      }
+
+//// Comments before 
+//// TODO: This needs some work to make sure that "a /* comment_before_b */ b" can't be generated
+////                                     but that "a /* comment_after_a  */ b" can
+// file                : [@child set_list]
+// set_list            : scoped_set [separator @sibling set_list] | unscoped_set [unscoped_separator @sibling set_list]
+// scoped_set          : {[tag_list] [@pre_comment pre_comment] untagged_scoped_set}
+// pre_comment         : '/' '/' [' '] [@fill c_code_content] '\n' | '/' '*' [@fill cpp_code_content] '*' '/'
+// c_code_content      : 'c''o''m''m''e''n''t' // TODO: Arbitrary strings, including C-style comments, as long as /* */ pairs are balanced
+// cpp_code_content    : 'c''o''m''m''e''n''t' // TODO: Arbitrary strings that don't start with space
+// untagged_scoped_set : '{' [@child set_list] '}' | alt_scope_beg [@child set_list] alt_scope_end
+// unscoped_set        : {[tag_list] @fill label [unscoped_set_tail]}
+// tag_list            : '@' @tag tag ' ' [tag_list]
+// tag                 : @fill id['(' [@child set_list] ')']
+// unscoped_set_tail   : {':' @child unscoped_set | ' ' @sibling unscoped_set | set_tail_hack | ' ' @sibling scoped_set}
+// set_tail_hack       : {':' [@child tag_list] '{' '}' | 
+//                        ':' @child [tag_list] '{' @child set_list '}' | 
+//                        ':' [@child tag_list] alt_scope_beg alt_scope_end | 
+//                        ':' @child [tag_list] alt_scope_beg @child set_list alt_scope_end
+//                       }