- add debug.local([<frame>]) to output local variables of frame #0

or of given frame
- add debug.string(<variable>). This returns the variable dump as
  string.
- add var to module function variables to avoid collisions with module names

Nasal/debug.nas

@@ -1,11 +1,20 @@
 # debug.nas -- debugging helpers
 #
-# debug.dump(<variable>)               ... dumps full contents of variable
+# debug.dump(<variable>)               ... dumps contents of variable to terminal;
+#                                          abbreviation for print(debug.string(v))
+#
+# debug.local([<frame:int>])           ... dump local variables of current
+#                                          or given frame
+#
 # debug.backtrace([<comment:string>]}  ... writes backtrace with local variables
 #                                          (similar to gdb's "bt full)
+#
 # debug.exit()                         ... exits fgfs
 #
 # debug.bt                             ... abbreviation for debug.backtrace
+#
+# debug.string(<variable>)             ... returns contents of variable as string
+#
 
 
 
@@ -20,23 +29,24 @@ if (caller(0)[2][1] != `:`) {
 
 # for color codes see  $ man console_codes
 #
-_title       = func(s) { _c("33;42;1", s) }	# backtrace header
+var _title       = func(s) { _c("33;42;1", s) } # backtrace header
-_section     = func(s) { _c("37;41;1", s) }	# backtrace frame
+var _section     = func(s) { _c("37;41;1", s) } # backtrace frame
+var _error       = func(s) { _c("31;1", s) }    # internal errors
 
-_nil         = func(s) { _c("32", s) }		# nil
+var _nil         = func(s) { _c("32", s) }      # nil
-_string      = func(s) { _c("31", s) }		# "foo"
+var _string      = func(s) { _c("31", s) }      # "foo"
-_num         = func(s) { _c("31", s) }		# 0.0
+var _num         = func(s) { _c("31", s) }      # 0.0
-_bracket     = func(s) { _c("", s) }		# [ ]
+var _bracket     = func(s) { _c("", s) }        # [ ]
-_brace       = func(s) { _c("", s) }		# { }
+var _brace       = func(s) { _c("", s) }        # { }
-_angle       = func(s) { _c("", s) }		# < >
+var _angle       = func(s) { _c("", s) }        # < >
-_vartype     = func(s) { _c("33", s) }		# func ghost
+var _vartype     = func(s) { _c("33", s) }      # func ghost
-_proptype    = func(s) { _c("34", s) }		# BOOL INT LONG DOUBLE ...
+var _proptype    = func(s) { _c("34", s) }      # BOOL INT LONG DOUBLE ...
-_path        = func(s) { _c("36", s) }		# /some/property/path
+var _path        = func(s) { _c("36", s) }      # /some/property/path
-_internal    = func(s) { _c("35", s) }		# me parents
+var _internal    = func(s) { _c("35", s) }      # me parents
-_varname     = func(s) { _c("1", s) }		# variable_name
+var _varname     = func(s) { _c("1", s) }       # variable_name
 
 
-_dump_prop = func(p) {
+var _dump_prop = func(p) {
 	var r = p.getAttribute("read")        ? "" : "r";
 	var w = p.getAttribute("write")       ? "" : "w";
 	var R = p.getAttribute("trace-read")  ? "R" : "";
@@ -46,11 +56,11 @@ _dump_prop = func(p) {
 	var T = p.getAttribute("tied")        ? "T" : "";
 	var attrib = r ~ w ~ R ~ W ~ A ~ U ~ T;
 	var type = "(" ~ _proptype(p.getType()) ~ (size(attrib) ? ", " ~ attrib : "") ~ ")";
-	return _path(p.getPath()) ~ "=" ~ _dump(p.getValue()) ~ " " ~ type;
+	return _path(p.getPath()) ~ "=" ~ string(p.getValue()) ~ " " ~ type;
 }
 
 
-_dump_var = func(v) {
+var _dump_var = func(v) {
 	if (v == "me" or v == "parents") {
 		return _internal(v);
 	} else {
@@ -59,7 +69,7 @@ _dump_var = func(v) {
 }
 
 
-_dump = func(o) {
+var string = func(o) {
 	var t = typeof(o);
 	if (t == "nil") {
 		return _nil("nil");
@@ -68,7 +78,7 @@ _dump = func(o) {
 	} elsif (t == "vector") {
 		var s = "";
 		forindex (var i; o) {
-			s ~= (i == 0 ? "" : ", ") ~ _dump(o[i]);
+			s ~= (i == 0 ? "" : ", ") ~ string(o[i]);
 		}
 		return _bracket("[") ~ " " ~ s ~ " " ~ _bracket("]");
 	} elsif (t == "hash") {
@@ -79,7 +89,7 @@ _dump = func(o) {
 		var k = keys(o);
 		var s = "";
 		forindex (var i; k) {
-			s ~= (i == 0 ? "" : ", ") ~ _dump_var(k[i]) ~ " : " ~ _dump(o[k[i]]);
+			s ~= (i == 0 ? "" : ", ") ~ _dump_var(k[i]) ~ " : " ~ string(o[k[i]]);
 		}
 		return _brace("{") ~ " " ~ s ~ " " ~ _brace("}");
 	} else {
@@ -88,10 +98,17 @@ _dump = func(o) {
 }
 
 
-dump = func(o = nil) { print(_dump(o != nil ? o : caller()[0])) }
+var dump = func { size(arg) ? print(string(arg[0])) : local(1) }
 
 
-backtrace = func(desc = nil, l = 0) {
+var local = func(frame = 0) {
+	var v = caller(frame + 1);
+	print(v == nil ? _error("<no such frame>") : string(v[0]));
+	return v;
+}
+
+
+var backtrace = func(desc = nil, l = 0) {
 	var v = caller(l);
 	if (v == nil) {
 		return;
@@ -105,10 +122,10 @@ backtrace = func(desc = nil, l = 0) {
 	}
 	backtrace(nil, l + 1);
 }
-bt = backtrace;
+var bt = backtrace;
 
 
-exit = func { fgcommand("exit", props.Node.new()) }
+var exit = func { fgcommand("exit", props.Node.new()) }
 
 
 if (getprop("/sim/logging/priority") != "alert") {