Commit Graph
2 Commits
Author SHA1 Message Date
Manos Pitsidianakis b905d2758d fix type_error with instantiated EOF -1 byte literal in get_byte/2
According to ISO Prolog, get_byte/2 predicate can receive an
instantiated input byte:

http://www.gprolog.org/manual/html_node/gprolog037.html#sec156

    get_byte(+stream_or_alias, ?in_byte)

Since in_byte can be -1 if EOF is reached, instantiating it with -1
should work but does not because the implementation is trying to convert
it to a u8 which is unsigned:

?- open("/dev/null", read, S, [type(binary)]), get_byte(S, -1).
   error(type_error(in_byte,-1),get_byte/2).

This commit adds an extra check for -1 before checking for a valid u8
instantiated value if in_byte is an input:

?- open("/dev/null", read, S, [type(binary)]), get_byte(S, -1).
   S = '$stream'(0x55601e65c998).

Closes #1625
2022-10-26 13:49:38 +03:00
Manos Pitsidianakis a9a06b5297 Fix xor/2 type error reporting wrong argument
If first argument n1 in xor/2 is of wrong numerical type, the match
patterns fall through to a catch all case that reports the second
argument in the type error.

Fixes #1626

`xor/2 function reports the wrong argument in type error #1626`

https://github.com/mthom/scryer-prolog/issues/1626
2022-10-24 19:26:43 +03:00