14.33.3 Bugs Fixed

• On 64-bit Windows, interrupting the program with library(timeout), ^C, and similar methods, could cause the process to exit abnormally. This was especially likely to happen on Windows 11.
• Stability and correctness have been improved in certain huge memory configurations and when handling very large integers.
• Calling peek_code/[1,2] or peek_byte/[1,2] would sometimes change the end_of_stream/1 stream property unexpectedly, e.g., when the stream was opened with option eof_action(eof_code).
• Fix GC hazards in library(mutarray).
• Several built-ins behaved unexpectedly, or removed awoken alternatives, if an output argument was an attributed variable. The affected predicates are: add_breakpoint/2, atom_concat/3, atom_length/2, char_code/2, coverage_data/1, frozen/2, number_chars/2, number_codes/2, read_term/[2,3], stream_property/2, sub_atom/5, and use_module/3.
• The reference documentation and error handling of use_module(Module, File, Imports) have been improved. Passing an argument of the wrong type could have unexpected effects, e.g., loading the file even if it was already loaded, or changing the type-in module. The file argument is always type-checked now. This is consistent with what use_module/[1,2] does. This change is unlikely to affect correct code.
• Several issues related to write_term/3 et al. have been fixed:
  • - A term containing an operator with precedence 1200, when the operator was declared as both postfix and infix, was sometimes written in a way that did not read back as the same term.

    Note that declaring the same operator name as both infix and postfix is disallowed by the ISO Prolog standard, and warned about in the SPIDER IDE.

  • - Operators as immediate argument of the operator , (comma) are now bracketed when written, as required by the ISO Prolog standard. E.g. writeq(((*),(*))) outputs ‘(*),(*)’ (it used to output ‘*,*’).

    Other operators have been treated this way since release 4.3.

  • - Writing a term with right associative operator (fy or xfy) with precedence 1200 no longer uses parentheses around its right argument if the right argument is written with a prefix or infix operator with the same precedence. This was never a problem for lower precedences.
  • - Writing an outer term with a non left associative principal functor (e.g. xf or xfy) would sometimes use unneeded parentheses around the left argument even when the operator of the left argument had lower precedence than that of the outer term.
  • - Writing an atom that is an operator name, like +, with write_term/3 will now wrap the atom with parentheses if a non-default priority/1 option is passed. This is for consistency with how the ISO Prolog standard defines the precedence of such atoms.

    As before, no parentheses are used when writing atoms when a default priority/1 option (1201) is explicitly or implicitly used.

  • - These changes should not affect the compatibility when reading terms written by earlier releases, or vice versa.
• The arithmetic expressions float_integer_part/1 and float_fractional_part/1 would sometimes wrongly accept an integer argument.
• The predicates current_input/1, current_output/1 and stream_property/2 now merely fail if the first argument is a closed stream, and similar cases, instead of throwing an error. This change is for alignment with the ISO Prolog standard.
• CLPFD:
  • - Wrong answer bugs in element/3 and table/2 with negative integers.
  • - Wrong answer bugs in linear arithmetic.