new commands:

debug.color(bool)                 turns terminal colors on/off
  debug.tree(property="", mode=1);  dumps property tree in flat
                                    mode (0) or space indented mode (1).

Flat tree mode is similar to props.debug(), but colored, and it outputs
all attribute flags and the number of attached listeners.

Nasal/debug.nas

@@ -1,4 +1,7 @@
 # debug.nas -- debugging helpers
+#------------------------------------------------------------------------------
+#
+# debug.color(<enabled>);              ... turns terminal colors on (1) or off (0)
 #
 # debug.dump(<variable>)               ... dumps contents of variable to terminal;
 #                                          abbreviation for print(debug.string(v))
@@ -9,6 +12,12 @@
 # debug.backtrace([<comment:string>]}  ... writes backtrace with local variables
 #                                          (similar to gdb's "bt full)
 #
+# debug.tree([<property> [, <mode>])   ... dump property tree under property path
+#                                          or props.Node hash (default: root). If
+#                                          <mode> is unset or 0, use flat mode
+#                                          (similar to props.dump()), otherwise
+#                                          use space indentation
+#
 # debug.exit()                         ... exits fgfs
 #
 # debug.bt                             ... abbreviation for debug.backtrace
@@ -16,14 +25,15 @@
 # debug.string(<variable>)             ... returns contents of variable as string
 #
 # debug.load_xml_nasal(<file>)         ... load and run XML embedded Nasal
-#
 
+var _c = nil;
 
-
+var color = func(enabled) {
-if (getprop("/sim/startup/terminal-ansi-colors")) {
+	if (enabled) {
-	_c = func(color, s) { "\x1b[" ~ color ~ "m" ~ s ~ "\x1b[m" }
+		_c = func(color, s) { "\x1b[" ~ color ~ "m" ~ s ~ "\x1b[m" }
-} else {
+	} else {
-	_c = func(dummy, s) { s }
+		_c = func(dummy, s) { s }
+	}
 }
 
 
@@ -46,7 +56,46 @@ var _internal    = func(s) { _c("35", s) }      # me parents
 var _varname     = func(s) { _c("1", s) }       # variable_name
 
 
-var _dump_prop = func(p) {
+var tree = func(p = "", graph = 1) {
+	var n = isa(p, props.Node) ? p : props.globals.getNode(p, 0);
+	if (n == nil)
+		dump(n);
+	else
+		_tree(n, graph);
+}
+
+
+var _tree = func(n, graph = 1, prefix = "", level = 0) {
+	var path = n.getPath();
+	var children = n.getChildren();
+	var s = "";
+
+	if (graph) {
+		s = prefix ~ n.getName();
+		var index = n.getIndex();
+		if (index)
+			s ~= "[" ~ index ~ "]";
+	} else {
+		s = n.getPath();
+	}
+
+	if (size(children)) {
+		s ~= "/";
+		if (n.getType() != "NONE")
+			s ~= " = " ~ string(n.getValue()) ~ " " ~ _attrib(n)
+					~ "    " ~ _section(" PARENT-VALUE ");
+	} else {
+		s ~= " = " ~ string(n.getValue()) ~ " " ~ _attrib(n);
+	}
+	print(s);
+
+	if (n.getType() != "ALIAS")
+		forindex (var i; children)
+			_tree(children[i], graph, prefix ~ ".   ", level + 1);
+}
+
+
+var _attrib = func(p) {
 	var r = p.getAttribute("read")        ? "" : "r";
 	var w = p.getAttribute("write")       ? "" : "w";
 	var R = p.getAttribute("trace-read")  ? "R" : "";
@@ -54,18 +103,26 @@ var _dump_prop = func(p) {
 	var A = p.getAttribute("archive")     ? "A" : "";
 	var U = p.getAttribute("userarchive") ? "U" : "";
 	var T = p.getAttribute("tied")        ? "T" : "";
-	var attrib = r ~ w ~ R ~ W ~ A ~ U ~ T;
+	var attr = r ~ w ~ R ~ W ~ A ~ U ~ T;
-	var type = "(" ~ _proptype(p.getType()) ~ (size(attrib) ? ", " ~ attrib : "") ~ ")";
+	var type = "(" ~ _proptype(p.getType());
-	return _path(p.getPath()) ~ "=" ~ string(p.getValue()) ~ " " ~ type;
+	if (size(attr))
+		type ~= ", " ~ attr;
+	if (var l = p.getAttribute("listeners"))
+		type ~= ", L" ~ l;
+	return type ~ ")";
+}
+
+
+var _dump_prop = func(p) {
+	_path(p.getPath()) ~ " = " ~ string(p.getValue()) ~ " " ~ _attrib(p);
 }
 
 
 var _dump_var = func(v) {
-	if (v == "me" or v == "parents") {
+	if (v == "me" or v == "parents")
 		return _internal(v);
-	} else {
+	else
 		return _varname(v);
-	}
 }
 
 
@@ -77,9 +134,9 @@ var string = func(o) {
 		return num(o) == nil ? _string('"' ~ o ~ '"') : _num(o);
 	} elsif (t == "vector") {
 		var s = "";
-		forindex (var i; o) {
+		forindex (var i; o)
 			s ~= (i == 0 ? "" : ", ") ~ string(o[i]);
-		}
+
 		return _bracket("[") ~ " " ~ s ~ " " ~ _bracket("]");
 	} elsif (t == "hash") {
 		if (contains(o, "parents") and typeof(o.parents) == "vector"
@@ -88,9 +145,9 @@ var string = func(o) {
 		}
 		var k = keys(o);
 		var s = "";
-		forindex (var i; k) {
+		forindex (var i; k)
 			s ~= (i == 0 ? "" : ", ") ~ _dump_var(k[i]) ~ " : " ~ string(o[k[i]]);
-		}
+
 		return _brace("{") ~ " " ~ s ~ " " ~ _brace("}");
 	} else {
 		return _angle("<") ~ _vartype(t) ~ _angle(">");
@@ -110,9 +167,9 @@ var local = func(frame = 0) {
 
 var backtrace = func(desc = nil, l = 0) {
 	var v = caller(l);
-	if (v == nil) {
+	if (v == nil)
 		return;
-	}
+
 	if (l == 0) {
 		var d = desc == nil ? "" : " '" ~ desc ~ "'";
 		print("\n" ~ _title("\n### backtrace" ~ d ~ " ###"));
@@ -173,3 +230,11 @@ var load_xml_nasal = func(file) {
 }
 
 
+
+_setlistener("/sim/signals/nasal-dir-initialized", func {
+	setlistener("/sim/startup/terminal-ansi-colors", func {
+		color(cmdarg().getBoolValue());
+	}, 1);
+});
+
+