@Override
protected void exec() {
    AWriter out = IO.wrapUTF8(System.out);

    // Generalize to abstract class for any "apply" - patch2rdf
    RDFChanges c =  new RDFChangesWriteUpdate(out);

    // Patches
    if ( getPositional().isEmpty() )
        execOne(System.in);

    getPositional().forEach(fn->{
        // Check patch threading?
        RDFPatch patch = RDFPatchOps.read(fn);
        if ( isVerbose() ) {
            System.err.printf("# Patch id=%s", Id.str(patch.getId()));
            if ( patch.getPrevious() != null )
                System.err.printf(" prev=%s", Id.str(patch.getPrevious()));
            System.err.println();
        }
        patch.apply(c);
    });
    out.flush();

}
 

@Test
public void fs_write_01() throws IOException {
    FileStore fs = FileStore.attach(STORE, "FILE");
    assertEquals(0, fs.getCurrentIndex());
    FileEntry entry = fs.writeNewFile(out->{
        try(AWriter aw = IO .wrapUTF8(out)) {
          aw.write("abc");
        }
    }) ;
    assertNotNull(entry);
    assertNotNull(entry.datafile);
    int idx = checkFilename(entry.datafile);
    assertEquals(1, idx);
    // Read it back in again.
    String s = FileUtils.readWholeFileAsUTF8(entry.getDatafileName());
    assertEquals("abc", s);
}
 

public RDFChangesWriteUpdate(AWriter out) {
    this.out = out;
    this.pmap = PrefixMapFactory.create();
    // Without prefixes on output - set pmap to null.
    // Avoid Jena 3.10.0 and earlier error that deleting prefixes does not stop abbreviation.
    // Fixes in Jena 3.11.0 when "pmap" can be used.
    this.formatter = new NodeFormatterTTL(null, /*pmap*/null) {
        @Override
        // Fix NodeFormatterTTL in Jena.
        public void formatBNode(AWriter w, Node n) {
            formatBNode(w, n.getBlankNodeLabel());
        }
        
        // Write as a URI.
        @Override
        public void formatBNode(AWriter w, String label) {
            w.print("<_:");
            String lab = NodeFmtLib.encodeBNodeLabel(label);
            w.print(lab);
            w.print(">");
        }
    };
}
 

@Override
   public void format(AWriter w, Node n) {
   	if ( n instanceof Node_Triple )
   		Helper.format(w, (Node_Triple) n, this);
   	else
   		wrappedFormatter.format(w, n);
}
 

static public void format(AWriter w, Node_Triple n, NodeFormatter nf) {
	final Triple t = n.get();

	w.print("<<");
	nf.format(w, t.getSubject());
	w.print(' ');
	nf.format(w, t.getPredicate());
	w.print(' ');
	nf.format(w, t.getObject());
	w.print(">>");
}
 

@Override
public void format(AWriter w, Node n) {
	if ( n instanceof Node_Triple )
		Helper.format(w, (Node_Triple) n, this);
	else
		super.format(w, n);
}
 

protected String serialize( Node n ) {
	StringWriter w = new StringWriter();
	try ( AWriter aw = Writer2.wrap(w) ) {
	    formatter.format(aw, n);
	}
	return w.toString();
}
 

public TokenWriterText(String label, NodeFormatter formatter, AWriter out) {
    if ( formatter == null )
        // For the number abbreviations.
        formatter = new NodeFormatterTTL(null, PrefixMapFactory.emptyPrefixMap());
    // Must write bNodes as <_:....>
    formatter = new NodeFormatterBNode(formatter);
    this.fmt = formatter;
    this.out = out;
    this.label = label;
}
 

@Override
public void format(AWriter w, Node n) {
    if ( n.isBlank() )
        formatBNode(w, n);
    else
        super.format(w, n);
}
 

@Override
   public void formatURI(AWriter w, Node n) {
	wrappedFormatter.formatURI(w, n);
}
 

@Override
   public void formatURI(AWriter w, String uriStr) {
	wrappedFormatter.formatURI(w, uriStr);
}
 

@Override
   public void formatVar(AWriter w, Node n) {
	wrappedFormatter.formatVar(w, n);
}
 

@Override
   public void formatVar(AWriter w, String name) {
	wrappedFormatter.formatVar(w, name);
}
 

@Override
   public void formatBNode(AWriter w, Node n) {
	wrappedFormatter.formatBNode(w, n);
}
 

@Override
   public void formatBNode(AWriter w, String label) {
	wrappedFormatter.formatBNode(w, label);
}
 

@Override
   public void formatLiteral(AWriter w, Node n) {
	wrappedFormatter.formatLiteral(w, n);
}
 

@Override
   public void formatLitString(AWriter w, String lex) {
	wrappedFormatter.formatLitString(w, lex);
}
 

@Override
   public void formatLitLang(AWriter w, String lex, String langTag) {
	wrappedFormatter.formatLitLang(w, lex, langTag);
}
 

@Override
   public void formatLitDT(AWriter w, String lex, String datatypeURI) {
	wrappedFormatter.formatLitDT(w, lex, datatypeURI);
}
 

@Override
public void formatBNode(AWriter w, Node n) {
    formatBNode(w, n.getBlankNodeLabel());
}
 

@Override
public void formatBNode(AWriter w, String label) {
    w.print("<_:");
    w.print(label);
    w.print(">");
}
 

@Override
public void format(AWriter w, Node n) {
    fmt.format(w, n);
}
 

@Override
public void formatURI(AWriter w, Node n) {
    fmt.formatURI(w, n);
}
 

@Override
public void formatURI(AWriter w, String uriStr) {
    fmt.formatURI(w, uriStr);
}
 

@Override
public void formatVar(AWriter w, Node n) {
    fmt.formatVar(w, n);
}
 

@Override
public void formatVar(AWriter w, String name) {
    fmt.formatVar(w, name);
}
 

@Override
public void formatBNode(AWriter w, Node n) {
    fmt.formatBNode(w, n);
}
 

@Override
public void formatBNode(AWriter w, String label) {
    fmt.formatBNode(w, label);
}
 

@Override
public void formatLiteral(AWriter w, Node n) {
    fmt.formatLiteral(w, n);
}
 

@Override
public void formatLitString(AWriter w, String lex) {
    fmt.formatLitString(w, lex);
}