shithub: pprolog

--- a/builtins.c

+++ b/builtins.c

@@ -872,6 +872,9 @@

 	if(error)

 		Throw(realterm);

+	if(realterm == nil)

+		Throw(syntaxerror(L"end of stream"));

 	Term *singlevars = nil;

 	Term *uniquevars = nil;

 	Term *varsnames = nil;

--- /dev/null

+++ b/loader.pl

@@ -1,0 +1,76 @@

+:- module(loader, []).

+load_module_from_file(File) :-

+	write('Loading file: '),

+	write(File),

+	nl,

+	( atom_concat(_, '.pl', File)

+	-> open(File, read, Stream)

+	; atom_concat(File, '.pl', File1),

+	  open(File1, read, Stream)

+	),

+	read_and_handle_terms(Stream, user, _),

+	close(Stream),

+	write('Loaded file: '),

+	write(File),

+	nl.

+read_and_handle_terms(Stream, Module0, Module) :-

+	( read_one_term(Stream, Term)

+	-> handle_term(Term, Module0, Module1),

+	   read_and_handle_terms(Stream, Module1, Module)

+	; Module = Module0

+	).

+read_one_term(Stream, Term) :-

+	consume_whitespace(Stream),

+	peek_char(Stream, NextCh),

+	NextCh \= end_of_file,

+	read_term(Stream, Term, []).

+whitespace(' ').

+whitespace('	').

+whitespace('

+').

+consume_whitespace(S) :-

+	peek_char(S, Ch),

+	( whitespace(Ch)

+	-> get_char(S, _), consume_whitespace(S)

+	; true

+	).

+handle_term(:- Directive, Module, NewModule) :-

+	!,

+	handle_directive(Directive, Module, NewModule).

+handle_term(Head :- Body, Module, Module) :-

+	!,

+	Module:assertz(Head :- Body).

+handle_term(Head --> Body, Module, Module) :-

+	!,

+	write('DCG RULE: '),

+	write(Head --> Body),

+	nl.

+handle_term(Head, Module, Module) :-

+	Module:assertz(Head).

+handle_directive(op(Priority, Specifier, Operator), Module, Module) :-

+	Module:op(Priority, Specifier, Operator).

+handle_directive(include(F), Module, NewModule) :-

+	open(F, read, S),

+	read_and_handle_terms(S, Module, NewModule),

+	close(S).

+handle_directive(ensure_loaded(F), Module, Module) :-

+	ensure_load(F).

+handle_directive(D, Module, Module) :-

+	write('Cannot handle directive: '),

+	write(D),

+	nl.

+ensure_loads(_) :- fail.

+ensure_load(F) :-

+	( ensure_loads(F)

+	-> true

+	; asserta(ensure_loads(F)), load_module_from_file(F)

+	).

--- a/mkfile

+++ b/mkfile

@@ -23,7 +23,8 @@

 PROLOGFILES=\

 	stdlib.pl\

-	repl.pl

+	repl.pl\

+	loader.pl

 default:V: all

--- a/module.c

+++ b/module.c

@@ -22,6 +22,7 @@

 	usermodule = addemptymodule(L"user");

 	parsemodule("/sys/lib/prolog/repl.pl");

+	parsemodule("/sys/lib/prolog/loader.pl");

 Module *

--- a/parser.c

+++ b/parser.c

@@ -73,7 +73,7 @@

 	currentmod = usermodule;

 	Term *result = prologtext(querymode);

-	if(querymode){

+	if(querymode && result){

 		uvlong id = 1;

 		result = copyterm(result, &id);

--- a/repl.pl

+++ b/repl.pl

@@ -1,11 +1,12 @@

 :- module(repl, []).

 repl([ProgName|Args]) :-

-	write('Welcome to p-prolog version 1'),

+	write('Welcome to p-prolog version 1.'),

nl,

 	write('Started with args: '),

 	write(Args),

nl,

+	flush_output,

 	handle_args(Args),

 	repl_loop.

@@ -12,14 +13,14 @@

 handle_arg('-d') :-

 	set_prolog_flag(debug, on).

 handle_arg(Arg) :-

-	( '$load_module_from_file'(Arg)

-	-> write('Loaded module from file: ')

-	; write('Failed to load module from file: ')

-	),

-	write(Arg), nl.

+	loader:load_module_from_file(Arg).

-handle_args([Arg|Rest]) :- handle_arg(Arg), !, handle_args(Rest).

+handle_args([Arg|Rest]) :- catch(handle_arg(Arg), E, handle_arg_error(E)), !, handle_args(Rest).

 handle_args([]).

+handle_arg_error(E) :-

+	write('Could not handle arg: '),

+	print_exception(E).

 repl_loop :-

 	catch(read_eval_print, E, print_exception(E)),

--- a/stdlib.pl

+++ b/stdlib.pl

@@ -122,7 +122,8 @@

 	current_input(S),

 	stream_property(S, end_of_stream(E)),

!,

-	(E = at ; E = past).

+	(E = at ; E = past),

+	!.

 at_end_of_stream(S_or_a) :-

 	( atom(S_or_a)

@@ -131,7 +132,8 @@

),

 	stream_property(S, end_of_stream(E)),

!,

-	(E = at; E = past).

+	(E = at; E = past),

+	!.

 % Standard exceptions

@@ -677,4 +679,9 @@

),

 	is_atom_or_var(Operator),

 	current_ops(Operators),

-	member(op(Priority, Op_specifier, Operator), Operators).

\ No newline at end of file

+	member(op(Priority, Op_specifier, Operator), Operators).

+% Loading prolog text

+consult(File) :-

+	loader:load_module_from_file(File).

--- a/streams.c

+++ b/streams.c

@@ -323,7 +323,8 @@

 	Stream *s = getstream(t);

 	Rune r = Bgetrune(s->bio);

-	Bungetrune(s->bio);

+	if(r != Beof)

+		Bungetrune(s->bio);

 	return r;

@@ -412,11 +413,12 @@

 	/* end_of_stream(E) */

 	if(s->mode == ReadStream){

 		Rune r = Bgetrune(s->bio);

-		Bungetrune(s->bio);

 		if(r == Beof)

 			arg = mkatom(L"at");

-		else

+		else{

+			Bungetrune(s->bio);

 			arg = mkatom(L"not");

+		}

 		data = copyterm(stream, nil);

 		data->next = mkcompound(L"end_of_stream", 1, arg);

 		prop = mkcompound(L"prop", 2, data);