Currently in PG, the precedence of = and <> is supposed to be equal, and the precedence of unary - is very high.
So, (true=1 between 1 and 1) parses as ((true)=(1 between 1 and 1)), and (true=-1 between 1 and 1) parses as ((true)=((-1) between 1 and 1)). All good so far. (true<>-1 between 1 and 1) parses as ((true<>(-1)) between 1 and 1). ??? The fault here is in the lexer. The input "<>-" is being lexed as an Op followed by '-' rather than as NOT_EQUAL followed by '-' because it looks like a match for a multi-character operator, with the - being thrown back into the input afterwards. So the precedence of <> gets inflated to that of Op, which is higher than BETWEEN. More seriously, this also breaks named arguments: create function f(a integer) returns integer language sql as $$ select a; $$; select f(a => 1); -- works select f(a => -1); -- works select f(a =>-1); -- ERROR: column "a" does not exist I guess the fix is to extend the existing special case code that checks for one character left after removing trailing [+-] and also check for the two-character ops "<>" ">=" "<=" "=>" "!=". -- Andrew (irc:RhodiumToad)
