演算子の優先順序

こちらのＲ入門資料から、

?Syntax

で、単項演算子(unary operators)と二項演算子(binary operators)の優先順位(precedence)が表示できる。
演算子に関する一般的な事項はこちら。

 The following unary and binary operators are defined.  They are
     listed in precedence groups, from highest to lowest.

       '[ [['             indexing                         
       ':: :::'           access variables in a name space 
       '$ @'              component / slot extraction      
       '^'                exponentiation (right to left)   
       '- +'              unary minus and plus             
       ':'                sequence operator                
       '%any%'            special operators                
       '* /'              multiply, divide                 
       '+ -'              (binary) add, subtract           
       '< > <= >= == !='  ordering and comparison          
       '!'                negation                         
       '&  &&'            and                              
       '| ||'             or                               
       '~'                as in formulae                   
       '-> ->>'           rightwards assignment            
       '='                assignment (right to left)       
       '<- <<-'           assignment (right to left)       
       '?'                help (unary and binary)          
      
     Within an expression operators of equal precedence are evaluated
     from left to right except where indicated.

     The links in the *See Also* section cover most other aspects of
     the basic syntax.