anchor.diff:  
   expression:
   	primaryExpr
  -	| unaryExpr
  +	| unary_op = (
  +		PLUS
  +		| MINUS
  +		| EXCLAMATION
  +		| CARET
  +		| STAR
  +		| AMPERSAND
  +		| RECEIVE
  +	) expression
   	| expression mul_op = (
   		STAR
   		| DIV
  
positive.code: 
  keyedElement: (key COLON)? element;
  
  key: IDENTIFIER | expression | literalValue;
  
  element: expression | literalValue;
  
  structType: STRUCT L_CURLY (fieldDecl eos)* R_CURLY;
  
  fieldDecl: (
  		{noTerminatorBetween(2)}? identifierList type_
  		| embeddedField
  	) tag = string_?;
  
  
negative.code: 	| IMAGINARY_LIT
  	| RUNE_LIT;
  
  operandName: IDENTIFIER;
  
  qualifiedIdent: IDENTIFIER DOT IDENTIFIER;
  
  