Sync with hdt-cpp fixes + minor cleanup

Makefile

@@ -41,10 +41,12 @@ $(SOBJ): $(OBJ) $(OBJ2)
 c/hdt4pl.o: c/hdt4pl.cpp $(HDTLIB)/libhdt.a $(CDSLIB)/libcds.a
 	$(CC) $(ARCH) $(CFLAGS) -c -o $@ c/hdt4pl.cpp
 
-$(HDTLIB)/libhdt.a $(HDTLIB)/libcds.a: FORCE
-	@# Assumes that ./configure has been run
+$(HDTLIB)/libhdt.a $(HDTLIB)/libcds.a: $(HDTHOME)/Makefile FORCE
 	set -x -e && $(MAKE) -C $(HDTHOME) $(MAKE_J)
 
+$(HDTHOME)/Makefile:
+	./configure
+
 FORCE:
 
 check::
@@ -64,3 +66,13 @@ distclean: clean
 	rm -f $(SOBJ)
 	[ ! -f $(HDTHOME)/Makefile ] || $(MAKE) -C $(HDTHOME) distclean
 	cd $(HDTHOME) && git clean -d -f -x
+
+# For development - need to have done pack_install(.)
+#   which also creates buildenv.sh, so you can do:
+#   make -C path/to/hdt dev-build
+# You may need to comment out the 'git reset' and 'git submodule update'
+# lines in configure and the "clean" rule of this Makefile
+
+dev-build:
+	. ./buildenv.sh && $(MAKE)
+	swipl -g run_tests -t halt test/test_hdt.pl

README.md

@@ -60,6 +60,8 @@ libraries.
 
 ## Notes
 
+See also [RDF basics wiki](https://swi-prolog.discourse.group/t/rdf-basics/4105).
+
 The `hdt-cpp` directory has a number of utilities in
 `hdt-cpp/libhdt/tools`.  For details, see `hdt-cpp/README.md`:
 * hdt2rdf

configure

@@ -2,13 +2,14 @@
 
 # TODO: The git commands should probably be in a "dependencies"
 #       step; however, that requires adding
-#       prolog:build_setp(dependencies, make) to build/make.pl
+#       prolog:build_step(dependencies, make) to build/make.pl
 
 set -e -x
 
 HDTHOME=hdt-cpp
 
-( [ ! -f ${HDTHOME}/autogen.sh ] || (cd ${HDTHOME} && git reset --hard) )
+# For development of hdt-cpp, comment out the following 2 lines:
+[ ! -f ${HDTHOME}/autogen.sh ] || (cd ${HDTHOME} && git reset --hard)
 git submodule update --init ${HDTHOME}
 
 cd ${HDTHOME}

test/data/example1.ttl

@@ -0,0 +1,25 @@
+# from  https://www.w3.org/TR/turtle/#sec-examples
+# (see also https://en.wikipedia.org/wiki/Turtle_(syntax)#Example)
+# with additional facts added
+
+@prefix rdf: <http://www.w3.org/1999/02/22-rdf-syntax-ns#> .
+@prefix dc: <http://purl.org/dc/elements/1.1/> .
+@prefix ex: <http://example.org/stuff/1.0a/> .
+
+<http://www.w3.org/TR/rdf-syntax-grammar>
+  dc:title "RDF/XML Syntax Specification (Revised)" ;
+  ex:editor [
+    ex:fullname "Dave Beckett";
+    ex:homePage <http://purl.org/net/dajobe/>
+  ] .
+
+<http://www.swi-prolog.org>
+  dc:title "SWI-Prolog" ;
+  dc:journal "Theory and Practice of Logic Programming" ;
+  ex:author [
+    ex:fullname "Jan Wielemaker";
+    ex:homePage  <http://www.swi-prolog.org>
+  ] ;
+  ex:author [
+    ex:fullname "Tom  Schrijvers"
+  ].

test/data/example2.ttl

@@ -0,0 +1,26 @@
+# from  https://www.w3.org/TR/turtle/#sec-examples
+
+PREFIX : <http://example.org/stuff/1.0b/>
+:a :b ( "apple" "banana" ) .
+
+@prefix : <http://example.org/stuff/1.0c/> .
+
+:a :b "The first line\nThe second line\n  more" .
+
+:a :b """The first line
+The second line
+  more""" .
+
+@prefix : <http://example.org/stuff/1.0d/> .
+(1 2.0 3E1) :p "w" .
+
+PREFIX : <http://example.org/stuff/1.0e/>
+(1 [:p :q] ( 2 ) ) :p2 :q2 .
+
+@prefix ericFoaf: <http://www.w3.org/People/Eric/ericP-foaf.rdf#> .
+@prefix : <http://xmlns.com/foaf/0.1/> .
+ericFoaf:ericP :givenName "Eric" ;
+              :knows <http://norman.walsh.name/knows/who/dan-brickley> ,
+                      [ :mbox <mailto:[email protected]> ] ,
+                      <http://getopenid.com/amyvdh> .
+