precedence of operators

One aspect of parsing precedence is associativity. A left-associative operator is one, such as *, with the property that x * y * z is parsed as (x * y) * z. A right-associative operator is one, such as =, with the property that x = y = z is parsed as x = (y = z). These operators are left associative: # #? % & * ** + ++ , - . .. ..< .? / // << @@ @@? ^ ^** ^< ^<= ^> ^>= ^^ _ _< _<= _> _>= | |_ || · ⊠ ⧢, and these operators are right associative: != %= &= **= *= ++= += -= -> ..<= ..= //= /= : := ; < <- <<= <= <== <=== <==> <==>= = =!= == === ===> ===>= ==> ==>= => > >= >> >>= ? ?? ??= @ @= @@= @@?= \ \= \\ \\= ^**= ^= ^^= _= |- |-= |= |_= ||= ~ ~= ·= ⊠= ⧢= and or SPACE xor .

Here are the operators arranged in order of increasing parsing precedence. For example, * has higher parsing precedence than +, and hence 2+3*5 is parsed as though it had been written as 2+(3*5). The symbol SPACE represents the operator that is used when two things are adjacent in program code.

 8                                                                                              ;                                                                                           
    
10                                                                                              ,                                                                                           
    
14  %=  &=  **=  *=  ++=  +=  -=  ->  ..<=  ..=  //=  /=  :=  <-  <<=  <==>=  =  ===>=  ==>=  =>  >>  >>=  ??=  @=  @@=  @@?=  \=  \\=  ^**=  ^=  ^^=  _=  |-=  |=  |_=  ||=  ~=  ·=  ⊠=  ⧢=
    
18                                                                                             <<                                                                                           
    
20                                                                                             |-                                                                                           
    
22                                                                                         <===  ===>                                                                                       
    
24                                                                                            <==>                                                                                          
    
26                                                                                          <==  ==>                                                                                        
    
28                                                                                           ??  or                                                                                         
    
30                                                                                             xor                                                                                          
    
32                                                                                             and                                                                                          
    
34                                                                                             not                                                                                          
    
36                                                                            !=  <  <=  =!=  ==  ===  >  >=  ?  ~                                                                          
    
38                                                                                             ||                                                                                           
    
40                                                                                              :                                                                                           
    
42                                                                                              |                                                                                           
    
44                                                                                             ^^                                                                                           
    
46                                                                                              &                                                                                           
    
48                                                                                           ..  ..<                                                                                        
    
50                                                                                          +  ++  -                                                                                        
    
52                                                                                              ·                                                                                           
    
54                                                                                          **  ⊠  ⧢                                                                                        
    
58                                                                                     %  *  /  //  \  \\                                                                                   
    
60                                                                                              @                                                                                           
    
62                                                                                            SPACE                                                                                         
    
64                                                                                             (*)                                                                                          
    
66                                                                                           @@  @@?                                                                                        
    
68                                                                                       ^*  ^~  _*  _~                                                                                     
    
70                                                               #  #?  .  .?  ^  ^**  ^<  ^<=  ^>  ^>=  _  _<  _<=  _>  _>=  |_                                                            
    
72                                                                                          !  ^!  _!

precedence of operators

See also