anchor.diff:  
       rule case_statement:
           TOKCASE LPAREN expr<<[]>> RPAREN
  -        ( MATCHES
  +        ( TOKMATCHES
             (
                 ( dot_field_selection
                 | LBRACE dot_field_ltagged (COMMA dot_field_ltagged)* RBRACE
  
positive.code:         TOKRETURN assign_value SEMICOLON
  
      rule group_statement:
          BEGIN
          statement_list
          END
  
      rule seq_statement:
          TOKSEQ
  
negative.code:     token TOKRESET_BY: "reset_by"
      token TOKRESULT: "result"
      token TOKRETURN: "return"
      token TOKRULE: "rule"
      token TOKRULES: "rules"
      token TOKSB: "SB"
      token TOKSBR: "SBR"
      token TOKSCHEDULE: "schedule"
      token TOKSEQ: "seq"
      token TOKSET: "set"
      token TOKSTRING: "String"
      token TOKSTRUCT: "struct"
      token TOKTAGGED: "tagged"
      token TOKTTYPE: "Type"
      token TOKTYPE: "type"
      token TOKTYPECLASS: "typeclass"
      token TOKTYPEDEF: "typedef"
      token TOKUNION: "union"
      token TOKWHILE: "while"
  
  