order of logical operations in CAS

[Wes Loewer]

I noticed that in Home A OR B AND C is treated as A OR (B AND C) as expected with AND having a higher precedence than OR.

However, in CAS a OR b AND c is treated as (a OR b) AND c, evaluating left to right with AND and OR having the same precedence.

For example:
Home:
true OR false AND false --> 1

CAS (and XCAS)
true OR false AND false --> false

Is this a bug, or is this the intended behavior?

[parisse]

Indeed, and and or have the same precedence in CAS because they are parsed with the same parser token in input_parser.yy (%left T_AND_OP), cf. input_lexer.ll

Code:


"&&"                    index_status(yyextra)=0; (*yylval)=gen(at_and,2); return T_AND_OP;
...
"||"                    index_status(yyextra)=0; (*yylval)=gen(at_ou,2); return T_AND_OP;

The same applies for xor and &

[Wes Loewer]

(10-14-2022 06:18 AM)parisse Wrote:  Indeed, and and or have the same precedence in CAS ...

Okay, that's good to know. Thank you for clarifying.