head	1.18;
access;
symbols;
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	ulrich:1.18; strict;
comment	@# @;


1.18
date	2024.02.14.10.05.57;	author ulrich;	state Exp;
branches;
next	1.17;

1.17
date	2015.04.08.13.32.07;	author ulrich;	state Exp;
branches;
next	1.16;

1.16
date	2014.07.28.12.54.43;	author ulrich;	state Exp;
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next	1.15;

1.15
date	2014.07.20.09.53.54;	author ulrich;	state Exp;
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next	1.14;

1.14
date	2014.07.19.13.18.30;	author ulrich;	state Exp;
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next	1.13;

1.13
date	2014.07.19.10.29.56;	author ulrich;	state Exp;
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next	1.12;

1.12
date	2014.07.19.10.28.17;	author ulrich;	state Exp;
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next	1.11;

1.11
date	2013.09.06.21.47.52;	author ulrich;	state Exp;
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next	1.10;

1.10
date	2013.09.06.21.47.05;	author ulrich;	state Exp;
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next	1.9;

1.9
date	2013.08.29.09.51.49;	author ulrich;	state Exp;
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next	1.8;

1.8
date	2013.08.28.19.18.25;	author ulrich;	state Exp;
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next	1.7;

1.7
date	2013.08.28.19.08.12;	author ulrich;	state Exp;
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1.6
date	2012.08.14.10.25.47;	author ulrich;	state Exp;
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1.5
date	2012.08.14.10.16.50;	author ulrich;	state Exp;
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1.4
date	2011.11.26.10.39.52;	author ulrich;	state Exp;
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1.3
date	2011.11.17.21.54.08;	author ulrich;	state Exp;
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1.2
date	2011.11.17.21.53.31;	author ulrich;	state Exp;
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next	1.1;

1.1
date	2011.07.13.17.32.19;	author ulrich;	state Exp;
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next	;


desc
@@


1.18
log
@Final version (just comments and spaces modified)
@
text
@% dcg_rule/2 expands a DCG rule into a Prolog rule, when no error
% condition is satisfied.

:- op(1105,xfy,'|').

dcg_rule(( NonTerminal, Terminals --> GRBody ), ( Head :- Body )) :-
   dcg_non_terminal(NonTerminal, S0,S, Head),
   dcg_body(GRBody, S0,S1, Goal1),
   dcg_terminals(Terminals, S, S1, Goal2),
   Body = ( Goal1, Goal2 ).
dcg_rule(( NonTerminal --> GRBody ), ( Head :- Body )) :-
   NonTerminal \= ( _, _ ),
   dcg_non_terminal(NonTerminal, S0,S, Head),
   dcg_body(GRBody, S0,S, Body).

dcg_non_terminal(NonTerminal, S0,S, Goal) :-
   NonTerminal =.. NonTerminalU,
   append(NonTerminalU,[S0,S], GoalU), % as defined in the Prolog prologue
   Goal =.. GoalU.

dcg_terminals(Terminals, S0,S, S0 = List) :-
   append(Terminals, S, List).

dcg_body(Var, S0,S, Body) :-
   var(Var),
   Body = phrase(Var, S0,S).
dcg_body(GRBody, S0,S, Body) :-
   nonvar(GRBody),
   dcg_constr(GRBody),
   dcg_cbody(GRBody, S0,S, Body).
dcg_body(NonTerminal, S0,S, Goal) :-
   nonvar(NonTerminal),
   \+ dcg_constr(NonTerminal),
   NonTerminal \= ( _ -> _ ),
   NonTerminal \= ( \+ _ ),
   dcg_non_terminal(NonTerminal, S0,S, Goal).

dcg_constr([]).        % 7.14.1
dcg_constr([_|_]).     % 7.14.2 - terminal sequence
dcg_constr(( _, _ )).  % 7.14.3 - concatenation
dcg_constr(( _ ; _ )). % 7.14.4 - alternative
                       % 7.14.5 - if-then-else
dcg_constr(( _'|'_ )). % 7.14.6 - alternative
dcg_constr({_}).       % 7.14.7
dcg_constr(call(_)).   % 7.14.8
dcg_constr(phrase(_)). % 7.14.9
dcg_constr(!).         % 7.14.10
% dcg_constr(\+ _).    % 7.14.11 - not (existence impl. defined)
% dcg_constr((_->_)).  % 7.14.12 - if-then (existence impl. defined)

dcg_cbody([], S0,S, S0 = S ).
dcg_cbody([T|Ts], S0,S, Goal) :-
   dcg_terminals([T|Ts], S0,S, Goal).
dcg_cbody(( GRFirst, GRSecond ), S0,S, ( First, Second )) :-
   dcg_body(GRFirst, S0,S1, First),
   dcg_body(GRSecond, S1,S, Second).
dcg_cbody(( GREither ; GROr ), S0,S, ( Either ; Or )) :-
   \+ subsumes_term(( _ -> _ ),GREither),
   dcg_body(GREither, S0,S, Either),
   dcg_body(GROr, S0,S, Or).
dcg_cbody(( GRCond ; GRElse ), S0,S, ( Cond ; Else )) :-
   subsumes_term(( _GRIf -> _GRThen ), GRCond),
   dcg_cbody(GRCond, S0,S, Cond),
   dcg_body(GRElse, S0,S, Else).
dcg_cbody(( GREither '|' GROr ), S0,S, ( Either ; Or )) :-
   dcg_body(GREither, S0,S, Either),
   dcg_body(GROr, S0,S, Or).
dcg_cbody({Goal}, S0,S, ( Goal, S0 = S )).
dcg_cbody(call(Cont), S0,S, call(Cont, S0,S)).
dcg_cbody(phrase(Body), S0,S, phrase(Body, S0,S)).
dcg_cbody(!, S0,S, ( !, S0 = S )).
dcg_cbody(\+ GRBody, S0,S, ( \+ phrase(GRBody,S0,_), S0 = S )).
dcg_cbody(( GRIf -> GRThen ), S0,S, ( If -> Then )) :-
   dcg_body(GRIf, S0,S1, If),
   dcg_body(GRThen, S1,S, Then).
@


1.17
log
@WG17 change - during meeting
@
text
@d1 3
a5 4
% This program uses append/3 as defined in the Prolog prologue.

% Expands a DCG rule into a Prolog rule, when no error condition applies.

d7 2
a8 2
   dcg_non_terminal(NonTerminal, S0, S, Head),
   dcg_body(GRBody, S0, S1, Goal1),
d13 2
a14 2
   dcg_non_terminal(NonTerminal, S0, S, Head),
   dcg_body(GRBody, S0, S, Body).
d16 4
a19 4
dcg_non_terminal(NonTerminal, S0, S, Goal) :-
   NonTerminal =.. NonTerminalUniv,
   append(NonTerminalUniv, [S0, S], GoalUniv),
   Goal =.. GoalUniv.
d21 1
a21 1
dcg_terminals(Terminals, S0, S, S0 = List) :-
d24 1
a24 1
dcg_body(Var, S0, S, Body) :-
d26 2
a27 2
   Body = phrase(Var, S0, S).
dcg_body(GRBody, S0, S, Body) :-
d30 2
a31 2
   dcg_cbody(GRBody, S0, S, Body).
dcg_body(NonTerminal, S0, S, Goal) :-
d36 1
a36 4
   dcg_non_terminal(NonTerminal, S0, S, Goal).

% The following constructs in a grammar rule body
% are defined in the corresponding subclauses.
d48 2
a49 5
% dcg_constr(\+ _).    % 7.14.11 - not (existence implementation dep.)
% dcg_constr((_->_)).  % 7.14.12 - if-then (existence implementation dep.)

% The principal functor of the first argument indicates
% the construct to be expanded.
d51 7
a57 7
dcg_cbody([], S0, S, S0 = S ).
dcg_cbody([T|Ts], S0, S, Goal) :-
   dcg_terminals([T|Ts], S0, S, Goal).
dcg_cbody(( GRFirst, GRSecond ), S0, S, ( First, Second )) :-
   dcg_body(GRFirst, S0, S1, First),
   dcg_body(GRSecond, S1, S, Second).
dcg_cbody(( GREither ; GROr ), S0, S, ( Either ; Or )) :-
d59 3
a61 3
   dcg_body(GREither, S0, S, Either),
   dcg_body(GROr, S0, S, Or).
dcg_cbody(( GRCond ; GRElse ), S0, S, ( Cond ; Else )) :-
d63 13
a75 13
   dcg_cbody(GRCond, S0, S, Cond),
   dcg_body(GRElse, S0, S, Else).
dcg_cbody(( GREither '|' GROr ), S0, S, ( Either ; Or )) :-
   dcg_body(GREither, S0, S, Either),
   dcg_body(GROr, S0, S, Or).
dcg_cbody({Goal}, S0, S, ( Goal, S0 = S )).
dcg_cbody(call(Cont), S0, S, call(Cont, S0, S)).
dcg_cbody(phrase(Body), S0, S, phrase(Body, S0, S)).
dcg_cbody(!, S0, S, ( !, S0 = S )).
dcg_cbody(\+ GRBody, S0, S, ( \+ phrase(GRBody,S0,_), S0 = S )).
dcg_cbody(( GRIf -> GRThen ), S0, S, ( If -> Then )) :-
   dcg_body(GRIf, S0, S1, If),
   dcg_body(GRThen, S1, S, Then).
@


1.16
log
@Post-meeting correction.
@
text
@d36 1
d42 12
a53 12
dcg_constr([]).          % 7.14.1
dcg_constr([_|_]).       % 7.14.2 - terminal sequence
dcg_constr(( _, _ )).    % 7.14.3 - concatenation
dcg_constr(( _ ; _ )).   % 7.14.4 - alternative
                         % 7.14.5 - if-then-else
dcg_constr(( _ '|' _ )). % 7.14.6 - alternative
dcg_constr({_}).         % 7.14.7
dcg_constr(call(_)).     % 7.14.8
dcg_constr(phrase(_)).   % 7.14.9
dcg_constr(!).           % 7.14.10
% dcg_constr(\+ _).      % 7.14.11 - not     (implementation dependent)
% dcg_constr((_ -> _)).  % 7.14.12 - if-then (implementation dependent)
d78 1
a79 1
dcg_cbody(!, S0, S, ( !, S0 = S )).
@


1.15
log
@Made variables for if-then-else more explicit.
Now mentions the otherwise implementation dependent (->)//2
@
text
@d51 2
a52 2
dcg_constr(\+ _).        % 7.14.11
% dcg_constr((_ -> _)).  % 7.14.12 - if-then (imlementation dependent)
d63 4
d68 2
a69 2
   \+ subsumes_term(( _GRIf -> _GRThen ), GRCond),
   dcg_body(GRCond, S0, S, Cond),
a70 4
dcg_cbody(( GREither ; GROr ), S0, S, ( Either ; Or )) :-
   subsumes_term(( _ -> _ ),GREither),
   dcg_cbody(GREither, S0, S, Either),
   dcg_body(GROr, S0, S, Or).
@


1.14
log
@Numbering back
@
text
@d52 1
d63 4
a66 4
dcg_cbody(( GREither ; GROr ), S0, S, ( Either ; Or )) :-
   \+ subsumes_term(( _ -> _ ),GREither),
   dcg_body(GREither, S0, S, Either),
   dcg_body(GROr, S0, S, Or).
@


1.13
log
@Changed expansion of (\+)//1
@
text
@d41 11
a51 11
dcg_constr([]).          % 7.15.1
dcg_constr([_|_]).       % 7.15.2 - terminal sequence
dcg_constr(( _, _ )).    % 7.15.3 - concatenation
dcg_constr(( _ ; _ )).   % 7.15.4 - alternative
                         % 7.15.5 - if-then-else
dcg_constr(( _ '|' _ )). % 7.15.6 - alternative
dcg_constr({_}).         % 7.15.7
dcg_constr(call(_)).     % 7.15.8
dcg_constr(phrase(_)).   % 7.15.9
dcg_constr(!).           % 7.15.10
dcg_constr(\+ _).        % 7.15.11
@


1.12
log
@WG17: remove iso_phrase/3
@
text
@d41 11
a51 11
dcg_constr([]).          % 7.14.1
dcg_constr([_|_]).       % 7.14.2 - terminal sequence
dcg_constr(( _, _ )).    % 7.14.3 - concatenation
dcg_constr(( _ ; _ )).   % 7.14.4 - alternative
                         % 7.14.5 - if-then-else
dcg_constr(( _ '|' _ )). % 7.14.6 - alternative
dcg_constr({_}).         % 7.14.7
dcg_constr(call(_)).     % 7.14.8
dcg_constr(phrase(_)).   % 7.14.9
dcg_constr(!).           % 7.14.10
dcg_constr(\+ _).        % 7.14.11
d76 1
a76 2
dcg_cbody(\+ GRBody, S0, S, ( \+ Goal, S0 = S )) :-
   dcg_body(GRBody, S0, _, Goal).
@


1.11
log
@wording
@
text
@a4 4
iso_phrase(GRBody, S0, S) :-
   dcg_body(GRBody, S0, S, Goal),
   call(Goal).

@


1.10
log
@dcg_rule/4 -> dcg_rule/2
many comments removed
spacings added
@
text
@d58 1
a58 1
% the construct to be translated.
@


1.9
log
@Added phrase//1 translation
@
text
@d9 1
a9 2
% dcg_rule(DCGrule, S0, S, Expansion).
% Translates a DCG rule into a Prolog rule, when no error condition applies.
d11 1
a11 1
dcg_rule((NonTerminal, Terminals --> GRBody), S0, S, (Head :- Body)) :-
d15 3
a17 3
   Body = (Goal1, Goal2).
dcg_rule((NonTerminal --> GRBody), S0, S, (Head :- Body)) :-
   NonTerminal \= (_,_),
a20 2
% translates a grammar goal non-terminal:

a25 2
% translates a terminal-sequence:

a28 2
% translates a grammar rule body:

d39 1
a39 1
   NonTerminal \= (_->_),
d45 11
a55 11
dcg_constr([]).        % 7.14.1
dcg_constr([_|_]).     % 7.14.2 - terminal sequence
dcg_constr((_,_)).     % 7.14.3 - concatenation
dcg_constr((_;_)).     % 7.14.4 - alternative
                       % 7.14.5 - if-then-else
dcg_constr((_'|'_)).   % 7.14.6 - alternative
dcg_constr({_}).       % 7.14.7
dcg_constr(call(_)).   % 7.14.8
dcg_constr(phrase(_)). % 7.14.9
dcg_constr(!).         % 7.14.10
dcg_constr(\+_).       % 7.14.11
d60 1
a60 1
dcg_cbody([], S0, S, (S0=S)).
d67 1
a67 1
   \+ subsumes_term((_->_),GREither),
d71 1
a71 1
   subsumes_term((_->_),GREither),
d77 1
a77 1
dcg_cbody({Goal}, S0, S, (Goal, S0 = S)).
d80 1
a80 1
dcg_cbody(\+ GRBody, S0, S, (\+ Goal, S0 = S)) :-
d82 1
a82 1
dcg_cbody(!, S0, S, (!, S0 = S)).
a85 2


@


1.8
log
@First dist
@
text
@d86 1
@


1.7
log
@First preliminary version to reflect Istanbul resolutions
@
text
@a2 1

a7 1

@


1.6
log
@Jan Burse: JB5: Either mention requirement of Prologue for Prolog or
give definition of append/3, to make it selfcontained.
@
text
@a18 1

d51 14
a64 9
dcg_constr([]).
dcg_constr([_|_]).
dcg_constr((_,_)).
dcg_constr((_;_)).
dcg_constr((_'|'_)).
dcg_constr(call(_)).
dcg_constr({_}).
dcg_constr(\+_).
dcg_constr(!).
d66 2
d76 4
a82 4
dcg_cbody(( GREither ; GROr ), S0, S, ( Either ; Or )) :-
   \+ subsumes_term((_->_),GREither),
   dcg_body(GREither, S0, S, Either),
   dcg_body(GROr, S0, S, Or).
d86 1
a87 1
dcg_cbody({Goal}, S0, S, (Goal, S0 = S)).
@


1.5
log
@Jan Burse: JB4: op/3 definition for '|' should be seen, to make it selfcontained.
@
text
@d3 3
@


1.4
log
@Added quotes for SICStus
@
text
@d1 2
@


1.3
log
@(New) added quotes to make Spec readable by SICStus too
@
text
@d51 1
a51 1
dcg_constr((_|_)).
@


1.2
log
@*** empty log message ***
@
text
@d72 1
a72 1
dcg_cbody(( GREither | GROr ), S0, S, ( Either ; Or )) :-
@


1.1
log
@Initial revision
@
text
@a9 1
   !,
d16 1
a35 1
   !,
d38 1
a39 1
   !,
d42 1
d44 1
d65 5
@