lib(quintus)


    ECLiPSe includes a Quintus Prolog compatibility package to ease the
    task of porting Quintus Prolog applications to ECLiPSe Prolog.  This
    package does not provide the user with a system completely compatible
    to Quintus Prolog, however it provides most of the Quintus built-in
    predicates, moreover some of the Quintus library predicates are
    available in the ECLiPSe library.  This package includes the C-Prolog
    compatibility package (see Appendix A.6). 
    
    Please note that this appendix does not detail the functionality of
    Quintus Prolog, refer to the Quintus Prolog documentation for this
    information. 
    
    The effect of the compatibility library is local to the module where
    it is loaded. For maximum compatibility, a Quintus program should
    be wrapped in a separate module starting with a directive like
    
    :- module(mymodule, [], quintus).
    
    In this case, Eclipse-specific language constructs will not be available.
    
    If the compatibility package is loaded into a standard module, e.g. like
    
    :- module(mymixedmdule).
    :- use_module(library(quintus)).
    
    then Quintus and Eclipse language features can be used together. 
    However, ambiguities must be resolved explicitly and confusion may
    arise from the different meaning of quotes in Eclipse vs Quintus-Prolog.
    
    The following differences remain even with the compatibility package: 
    
    expand_term/2 
	This predicate is dummy, since the ECLiPSe macro facility
	works on every input term, provided that the flag
	macro_expansion is set to on. 
    get0/2 
	This predicate is identical to get/2 in ECLiPSe. 
    help/1 
	This is the normal ECLiPSe help/1 predicate. 
    meta_predicate/1 
	This declaration does not cause passing of module information
	in Quintus-style, as ECLiPSe's concept of meta predicates
	differs substantially.  The meta-predicates very likely have
	to be modified manually to use ECLiPSe tools (see User Manual).
    multifile/1 
	This is implemented by declaring the predicates as dynamic, so
	to obtain more efficient programs it is better to put all
	clauses of the same procedure into one file (or to concatenate
	all files where multifile predicates occur). 
    predicate_property/2 
	The property interpreted is not provided.  The property
	exported is returned if the predicate is exported or global. 
	Use of get_flag/3 should be preferred. 
    prolog_flag/2, 3 
	There are some differences in the flags, as they are mostly
	simulated with the ECLiPSe flags:
	
	    not all the character escapes used in the Quintus Prolog
	    are available.
	    gc_margin is taken as the ECLiPSe flag gc_interval
	    (see Section 19.2)
	    setting gc_trace to on sets also gc to on
	
    public/1
	synonym for export/1 
    statistics/0, 2 
	these predicates are slightly different than in Quintus, in
	particular the meaning of the memory statistics is approximate,
	and the output format is different.
    ttyflush/0, ttyget/1, ttyget0/1, ttynl/0, ttyput/1, ttyskip/1, ttytab/1 
	these predicates work with the stdout stream 
    line_position/2
	Not implemented.  To perform sophisticated output formatting,
	printf/2,3 or string streams can be used.
    
    The list below describes the syntax differences between
    ECLiPSe and Quintus Prolog.  The following properties of Quintus
    Prolog are simulated by the compatibility package: 
    
	single (resp.  double) quote must be doubled between
	    single (resp.  double) quote. 
	The symbol | (bar) is recognised as an alternative sign
	    for a disjunction and it acts as an infix operator. 
	the symbol | is not an atom
    
    The following Quintus properties are not simulated: 
    
	a clause can not be ended by end of file. 
	signed numbers: explicitly positive numbers are structures. 
	a real with an exponent must have a floating point. 
	a space is allowed before the decimal point and the exponent sign. 
	the definition of the escape sequence is more extended
	    than in ECLiPSe. 
	spy/1 and nospy/1 accept as arguments lists, rather than
	    comma-separated terms like in ECLiPSe. 
    
    

