Hi,

I am using gprolog 1.4.4.  According to the manual, by default, the flag
`back_quotes` is set to ` atom_no_escape`, which means no escape sequence
is supported inside back quotes.  But I surprisingly find that it is not
the case.  Below is a dialog of an interactive session:


GNU Prolog 1.4.4 (32 bits)
Compiled Apr 29 2013, 20:41:58 with gcc
By Daniel Diaz
Copyright (C) 1999-2013 Daniel Diaz
| ?- current_prolog_flag(back_quotes, X).

X = atom_no_escape

yes
| ?- atom_chars('''', CS).

CS = ['''']

yes
| ?- atom_chars('\'', CS).

CS = ['''']

yes
| ?- atom_chars('\\', CS).

CS = [\]

yes
| ?- atom_chars('\n', CS).

CS = ['\n']

yes
| ?- atom_chars('\''', CS).
uncaught exception: error(syntax_error('user_input:6 (char:23) unexpected
newline'),read_term/3)


Apparently escape sequences are still allowed.  How can I disable it?  Note
that turning on the flag ` strict_iso` does not help.  Is this a bug?


Regards,


Yi
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