constant::= string | integer | float | boolean | uuid | blob | NULL
string::= ''' (any character where ' can appear if doubled)+ ''' : '$$' (any character other than '$$') '$$'
integer::= re('-?[0-9]+')
float::= re('-?[0-9]+(.[0-9]*)?([eE][+-]?[0-9+])?') | NAN | INFINITY
boolean::= TRUE | FALSE
uuid::= hex\{8}-hex\{4}-hex\{4}-hex\{4}-hex\{12}
hex::= re("[0-9a-fA-F]")
blob::= '0' ('x' | 'X') hex+