diff --git a/binr/radare2/radare2.c b/binr/radare2/radare2.c
index f7042e3daf..8ba1d2b767 100644
--- a/binr/radare2/radare2.c
+++ b/binr/radare2/radare2.c
@@ -1341,7 +1341,7 @@ int main(int argc, char **argv, char **envp) {
 		}
 
 		// no flagspace selected by default the beginning
-		r.flags->space_idx = -1;
+		r_flag_space_set (r.flags, NULL);
 		/* load <file>.r2 */
 		{
 			char f[128];
@@ -1440,7 +1440,7 @@ int main(int argc, char **argv, char **envp) {
 		}
 
 		// no flagspace selected by default the beginning
-		r.flags->space_idx = -1;
+		r_flag_space_set (r.flags, NULL);
 		if (!debug && r.bin && r.bin->cur && r.bin->cur->o && r.bin->cur->o->info) {
 			if (r.bin->cur->o->info->arch) {
 				r_core_cmd0 (&r, "aeip");
diff --git a/libr/core/cmd.c b/libr/core/cmd.c
index ec9bed29f8..416238bb21 100644
--- a/libr/core/cmd.c
+++ b/libr/core/cmd.c
@@ -2663,7 +2663,7 @@ escape_backtick:
 		bool is_arch_set = false;
 		char *tmpeval = NULL;
 		char *tmpasm = NULL;
-		int flgspc = -123;
+		bool flgspc_changed = false;
 		int tmpfd = -1;
 		int sz, len;
 		ut8 *buf;
@@ -2718,8 +2718,7 @@ repeat_arroba:
 		} else if (ptr[0] && ptr[1] == ':' && ptr[2]) {
 			switch (ptr[0]) {
 			case 'F': // "@F:" // temporary flag space
-				flgspc = r_flag_space_get (core->flags, ptr + 2);
-				r_flag_space_set (core->flags, ptr + 2);
+				flgspc_changed = r_flag_space_push (core->flags, ptr + 2);
 				break;
 			case 'B': // "@B:#" // seek to the last instruction in current bb
 				{
@@ -3002,8 +3001,8 @@ next_arroba:
 			r_core_cmd0 (core, tmpeval);
 			R_FREE (tmpeval);
 		}
-		if (flgspc != -123) {
-			r_flag_space_set_i (core->flags, flgspc);
+		if (flgspc_changed) {
+			r_flag_space_pop (core->flags);
 		}
 		*ptr = '@';
 		rc = ret;
@@ -3607,7 +3606,7 @@ R_API int r_core_cmd_foreach(RCore *core, const char *cmd, char *each) {
 			}
 			str[i] = ch;
 			{
-				int flagspace = core->flags->space_idx;
+				const RSpace *flagspace = r_flag_space_cur (core->flags);
 				RList *match_flag_items = r_list_newf ((RListFree)r_flag_item_free);
 				if (!match_flag_items) {
 					break;
@@ -3642,7 +3641,6 @@ R_API int r_core_cmd_foreach(RCore *core, const char *cmd, char *each) {
 				}
 
 				r_list_free (match_flag_items);
-				core->flags->space_idx = flagspace;
 				core->rcmd->macro.counter++ ;
 				R_FREE (word);
 			}
diff --git a/libr/core/cmd_flag.c b/libr/core/cmd_flag.c
index bf289e4088..694ff3ee5a 100644
--- a/libr/core/cmd_flag.c
+++ b/libr/core/cmd_flag.c
@@ -341,6 +341,56 @@ static bool adjust_offset(RFlagItem *flag, void *user) {
 	return true;
 }
 
+static void print_space_stack(RFlag *f, int ordinal, const char *name, bool selected, PJ *pj, int mode) {
+	bool first = ordinal == 0;
+	switch (mode) {
+	case 'j': {
+		char *ename = r_str_escape (name);
+		if (!ename) {
+			return;
+		}
+
+		pj_o (pj);
+		pj_ki (pj, "ordinal", ordinal);
+		pj_ks (pj, "name", ename);
+		pj_kb (pj, "selected", selected);
+		pj_end (pj);
+		free (ename);
+		break;
+	}
+	case '*': {
+		const char *fmt = first? "fs %s\n": "fs+%s\n";
+		r_cons_printf (fmt, name);
+		break;
+	}
+	default:
+		r_cons_printf ("%-2d %s%s\n", ordinal, name, selected? " (selected)": "");
+		break;
+	}
+}
+
+static int flag_space_stack_list(RFlag *f, int mode) {
+	RListIter *iter;
+	char *space;
+	int i = 0;
+	PJ *pj = NULL;
+	if (mode == 'j') {
+		pj = pj_new ();
+		pj_a (pj);
+	}
+	r_list_foreach (f->spaces.spacestack, iter, space) {
+		print_space_stack (f, i++, space, false, pj, mode);
+	}
+	const char *cur_name = r_flag_space_cur_name (f);
+	print_space_stack (f, i++, cur_name, true, pj, mode);
+	if (mode == 'j') {
+		pj_end (pj);
+		r_cons_printf ("%s\n", pj_string (pj));
+		pj_free (pj);
+	}
+	return i;
+}
+
 static int cmd_flag(void *data, const char *input) {
 	static int flagenum = 0;
 	RCore *core = (RCore *)data;
@@ -709,19 +759,20 @@ rep:
 			}
 			break;
 		case 's':
-			r_flag_space_stack_list (core->flags, input[2]);
+			flag_space_stack_list (core->flags, input[2]);
 			break;
 		case '-':
 			switch (input[2]) {
 			case '*':
 				r_flag_space_unset (core->flags, NULL);
 				break;
-			case '.':
-				{
-				const char *curfs = r_flag_space_cur (core->flags);
-				r_flag_space_unset (core->flags, curfs);
+			case '.': {
+				const RSpace *sp = r_flag_space_cur (core->flags);
+				if (sp) {
+					r_flag_space_unset (core->flags, sp->name);
 				}
 				break;
+			}
 			case 0:
 				r_flag_space_pop (core->flags);
 				break;
@@ -734,7 +785,7 @@ rep:
 		case '\0':
 		case '*':
 		case 'q':
-			r_flag_space_list (core->flags, input[1]);
+			spaces_list (&core->flags->spaces, input[1]);
 			break;
 		case ' ':
 			r_flag_space_set (core->flags, input+2);
@@ -747,21 +798,15 @@ rep:
 			}
 			f = r_flag_get_i (core->flags, off);
 			if (f) {
-				f->space = core->flags->space_idx;
+				f->space = r_flag_space_cur (core->flags);
 			} else {
 				eprintf ("Cannot find any flag at 0x%"PFMT64x".\n", off);
 			}
 			}
 			break;
-		default: {
-			int i, j = 0;
-			for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-				if (core->flags->spaces[i])
-					r_cons_printf ("%02d %c %s\n", j++,
-					(i == core->flags->space_idx)?'*':' ',
-					core->flags->spaces[i]);
-			}
-			} break;
+		default:
+			spaces_list (&core->flags->spaces, 0);
+			break;
 		}
 		break;
 	case 'g':
@@ -888,7 +933,6 @@ rep:
 			ut64 addr = core->offset;
 			char *arg = NULL;
 			RFlagItem *f = NULL;
-			bool space_strict = true;
 			bool strict_offset = false;
 			switch (input[1]) {
 			case '?':
@@ -901,7 +945,6 @@ rep:
 				addr = core->offset;
 				break;
 			case 'd':
-				space_strict = false;
 				arg = strchr (input, ' ');
 				if (arg) {
 					addr = r_num_math (core->num, arg + 1);
@@ -924,47 +967,46 @@ rep:
 				}
 				return 0;
 				}
-			case 'w':
-				{
+			case 'w': {
 				arg = strchr (input, ' ');
-				if (arg) {
-					arg++;
-					if (*arg) {
-						RFlag *f = core->flags;
-						RList *temp = r_flag_all_list (f);
-						ut64 loff = 0; 
-						ut64 uoff = 0;
-						ut64 curseek = core->offset;
-						char *lmatch = NULL , *umatch = NULL;
-						RFlagItem *flag;
-						RListIter *iter;
-						r_list_sort (temp, &cmpflag);
-						r_list_foreach (temp, iter, flag) {
-							if ((f->space_idx != -1) && (flag->space != f->space_idx)) {
-								continue;
-							}
-							if (strstr (flag->name , arg) != NULL) {
-								if (flag->offset < core->offset) {
-									loff = flag->offset;
-									lmatch = flag->name;							
-									continue;
-								}
-								uoff = flag->offset;
-								umatch = flag->name;
-								break;
-							}	
-						}		
-						char *match = (curseek - loff) < (uoff - curseek) ? lmatch : umatch ;
-						if (match) {
-							if (*match) {
-								r_cons_println (match);
-							}
-						}	
-						r_list_free (temp);
-					}	
+				if (!arg) {
+					return 0;
 				}
+				arg++;
+				if (!*arg) {
+					return 0;
+				}
+
+				RFlag *f = core->flags;
+				RList *temp = r_flag_all_list (f, true);
+				ut64 loff = 0;
+				ut64 uoff = 0;
+				ut64 curseek = core->offset;
+				char *lmatch = NULL , *umatch = NULL;
+				RFlagItem *flag;
+				RListIter *iter;
+				r_list_sort (temp, &cmpflag);
+				r_list_foreach (temp, iter, flag) {
+					if (strstr (flag->name , arg) != NULL) {
+						if (flag->offset < core->offset) {
+							loff = flag->offset;
+							lmatch = flag->name;
+							continue;
+						}
+						uoff = flag->offset;
+						umatch = flag->name;
+						break;
+					}
+				}
+				char *match = (curseek - loff) < (uoff - curseek) ? lmatch : umatch ;
+				if (match) {
+					if (*match) {
+						r_cons_println (match);
+					}
+				}
+				r_list_free (temp);
 				return 0;
-				}	
+			}
 			default:
 				arg = strchr (input, ' ');
 				if (arg) {
@@ -972,9 +1014,7 @@ rep:
 				}
 				break;
 			}
-			core->flags->space_strict = space_strict;
 			f = r_flag_get_at (core->flags, addr, !strict_offset);
-			core->flags->space_strict = false;
 			if (f) {
 				if (f->offset != addr) {
 					// if input contains 'j' print json
diff --git a/libr/core/cmd_meta.c b/libr/core/cmd_meta.c
index a6c464dbbd..89c0a94d73 100644
--- a/libr/core/cmd_meta.c
+++ b/libr/core/cmd_meta.c
@@ -1098,17 +1098,10 @@ static int cmd_meta(void *data, const char *input) {
 		case ' ': // "CS "
 			r_spaces_set (ms, input + 2);
 			break;
-		default: {
-			RSpace *s;
-			RBIter it;
-			const RSpace *cur = r_spaces_current (ms);
-			r_rbtree_foreach (ms->spaces, it, s, RSpace, rb) {
-				r_cons_printf ("%c %s\n", (s == cur)? '*': ' ',
-					s->name);
-			}
+		default:
+			spaces_list (ms, 0);
 			break;
 		}
-		}
 		break;
 	}
 	return true;
diff --git a/libr/core/cmd_print.c b/libr/core/cmd_print.c
index b1c9d801e0..80c1d99e62 100644
--- a/libr/core/cmd_print.c
+++ b/libr/core/cmd_print.c
@@ -1761,7 +1761,7 @@ R_API void r_core_print_examine(RCore *core, const char *str) {
 }
 
 struct count_pz_t {
-	int flagspace;
+	RSpace *flagspace;
 	ut64 addr;
 	ut64 size;
 	int *ret;
@@ -1821,8 +1821,7 @@ static int printzoomcallback(void *user, int mode, ut64 addr, ut8 *bufz, ut64 si
 		}
 		break;
 	case 's': // "pzs"
-		j = r_flag_space_get (core->flags, "strings");
-		u.flagspace = j;
+		u.flagspace = r_flag_space_get (core->flags, "strings");
 		u.addr = addr;
 		u.size = size;
 		u.ret = &ret;
diff --git a/libr/core/cmd_seek.c b/libr/core/cmd_seek.c
index e3054e6e76..28585c02ad 100644
--- a/libr/core/cmd_seek.c
+++ b/libr/core/cmd_seek.c
@@ -493,9 +493,7 @@ static int cmd_seek(void *data, const char *input) {
 				r_list_foreach (list, iter, undo) {
 					char *name = NULL;
 
-					core->flags->space_strict = true;
 					RFlagItem *f = r_flag_get_at (core->flags, undo->off, true);
-					core->flags->space_strict = false;
 					if (f) {
 						if (f->offset != undo->off) {
 							name = r_str_newf ("%s+%d", f->name,
@@ -551,9 +549,7 @@ static int cmd_seek(void *data, const char *input) {
 				r_list_foreach (list, iter, undo) {
 					char *name = NULL;
 
-					core->flags->space_strict = true;
 					RFlagItem *f = r_flag_get_at (core->flags, undo->off, true);
-					core->flags->space_strict = false;
 					if (f) {
 						if (f->offset != undo->off) {
 							name = r_str_newf ("%s + %d\n", f->name,
diff --git a/libr/core/core.c b/libr/core/core.c
index 4eefb3bcbe..380c3010d4 100644
--- a/libr/core/core.c
+++ b/libr/core/core.c
@@ -1173,10 +1173,10 @@ static void autocomplete_zignatures(RLine* line, const char* msg) {
 	int length = strlen (msg);
 	RSpaces *zs = &core->anal->zign_spaces;
 	RSpace *s;
-	RBIter it;
+	RSpaceIter it;
 	int i = 0;
 
-	r_rbtree_foreach (zs->spaces, it, s, RSpace, rb) {
+	r_spaces_foreach (zs, it, s) {
 		if (i == TMP_ARGV_SZ - 1) {
 			break;
 		}
@@ -1202,23 +1202,21 @@ static void autocomplete_flagspaces(RLine* line, const char* msg) {
 	}
 	int length = strlen (msg);
 	RFlag *flag = core->flags;
-	int j, i = 0;
-	for (j = 0; j < R_FLAG_SPACES_MAX - 1; j++) {
-		if (flag->spaces[j] && flag->spaces[j][0]) {
-			if (i == TMP_ARGV_SZ - 1) {
-				break;
-			}
-			if (!strncmp (msg, flag->spaces[j], length)) {
-				if (i + 1 < TMP_ARGV_SZ) {
-					tmp_argv[i++] = flag->spaces[j];
-				}
+	int i = 0;
+	RSpaceIter it;
+	RSpace *s;
+	r_flag_space_foreach (flag, it, s) {
+		if (i == TMP_ARGV_SZ - 1) {
+			break;
+		}
+		if (!strncmp (msg, s->name, length)) {
+			if (i + 1 < TMP_ARGV_SZ) {
+				tmp_argv[i++] = s->name;
 			}
 		}
 	}
-	if (flag->spaces[j] && !strncmp (msg, flag->spaces[j], strlen (msg))) {
-		if (i + 1 < TMP_ARGV_SZ) {
-			tmp_argv[i++] = "*";
-		}
+	if (i + 1 < TMP_ARGV_SZ) {
+		tmp_argv[i++] = "*";
 	}
 	tmp_argv[i] = NULL;
 	line->completion.argc = i;
@@ -2209,25 +2207,28 @@ static char *get_comments_cb(void *user, ut64 addr) {
 }
 
 R_IPI void spaces_list(RSpaces *sp, int mode) {
-	RBIter it;
+	RSpaceIter it;
 	RSpace *s;
 	bool first = true;
 	const RSpace *cur = r_spaces_current (sp);
+	PJ *pj = NULL;
 	if (mode == 'j') {
-		r_cons_printf ("[");
+		pj = pj_new ();
+		pj_a (pj);
 	}
-	r_rbtree_foreach (sp->spaces, it, s, RSpace, rb) {
+	r_spaces_foreach (sp, it, s) {
 		int count = r_spaces_count (sp, s->name);
 		if (mode == 'j') {
-			r_cons_printf ("%s{\"name\":\"%s\"%s,\"count\":%d}",
-				       !first? ",": "", s->name,
-				       cur == s? ",\"selected\":true": "",
-				       count);
+			pj_o (pj);
+			pj_ks (pj, "name", s->name);
+			pj_ki (pj, "count", count);
+			pj_kb (pj, "selected", cur == s);
+			pj_end (pj);
 		} else if (mode == '*') {
 			r_cons_printf ("%s %s\n", sp->name, s->name);
 		} else {
-			r_cons_printf ("%d %c %s\n", count, cur == s? '*': '.',
-				       s->name);
+			r_cons_printf ("%5d %c %s\n", count, (!cur || cur == s)? '*': '.',
+				s->name);
 		}
 		first = false;
 	}
@@ -2235,7 +2236,9 @@ R_IPI void spaces_list(RSpaces *sp, int mode) {
 		r_cons_printf ("%s %s # current\n", sp->name, r_spaces_current_name (sp));
 	}
 	if (mode == 'j') {
-		r_cons_printf ("]\n");
+		pj_end (pj);
+		r_cons_printf ("%s\n", pj_string (pj));
+		pj_free (pj);
 	}
 }
 
diff --git a/libr/core/disasm.c b/libr/core/disasm.c
index 04f8623c6b..51a07ef3d9 100644
--- a/libr/core/disasm.c
+++ b/libr/core/disasm.c
@@ -160,7 +160,7 @@ typedef struct {
 	RStrEnc strenc;
 	int cursor;
 	int show_comment_right_default;
-	int flagspace_ports;
+	RSpace *flagspace_ports;
 	int show_flag_in_bytes;
 	int lbytes;
 	int show_comment_right;
@@ -985,18 +985,18 @@ static void ds_build_op_str(RDisasmState *ds, bool print_color) {
 			ds->opstr = strdup (ds->hint->opcode);
 		}
 		if (ds->filter) {
-			int ofs = core->parser->flagspace;
-			int fs = ds->flagspace_ports;
+			RSpace *ofs = core->parser->flagspace;
+			RSpace *fs = ds->flagspace_ports;
 			if (ds->analop.type == R_ANAL_OP_TYPE_IO) {
-				core->parser->notin_flagspace = -1;
+				core->parser->notin_flagspace = NULL;
 				core->parser->flagspace = fs;
 			} else {
-				if (fs != -1) {
+				if (fs) {
 					core->parser->notin_flagspace = fs;
 					core->parser->flagspace = fs;
 				} else {
-					core->parser->notin_flagspace = -1;
-					core->parser->flagspace = -1;
+					core->parser->notin_flagspace = NULL;
+					core->parser->flagspace = NULL;
 				}
 			}
 			if (ds->analop.refptr) {
@@ -5362,18 +5362,18 @@ R_API int r_core_print_disasm_instructions(RCore *core, int nb_bytes, int nb_opc
 				}
 			} else if (ds->filter) {
 				char *asm_str;
-				int ofs = core->parser->flagspace;
-				int fs = ds->flagspace_ports;
+				RSpace *ofs = core->parser->flagspace;
+				RSpace *fs = ds->flagspace_ports;
 				if (ds->analop.type == R_ANAL_OP_TYPE_IO) {
-					core->parser->notin_flagspace = -1;
+					core->parser->notin_flagspace = NULL;
 					core->parser->flagspace = fs;
 				} else {
-					if (fs != -1) {
+					if (fs) {
 						core->parser->notin_flagspace = fs;
 						core->parser->flagspace = fs;
 					} else {
-						core->parser->notin_flagspace = -1;
-						core->parser->flagspace = -1;
+						core->parser->notin_flagspace = NULL;
+						core->parser->flagspace = NULL;
 					}
 				}
 				core->parser->hint = ds->hint;
diff --git a/libr/core/project.c b/libr/core/project.c
index 2563743c29..ca8aba6ecd 100644
--- a/libr/core/project.c
+++ b/libr/core/project.c
@@ -606,7 +606,7 @@ static bool simpleProjectSaveScript(RCore *core, const char *file, int opts) {
 
 static bool projectSaveScript(RCore *core, const char *file, int opts) {
 	char *filename, *hl, *ohl = NULL;
-	int fd, fdold, tmp;
+	int fd, fdold;
 
 	if (!file || *file == '\0') {
 		return false;
@@ -633,10 +633,9 @@ static bool projectSaveScript(RCore *core, const char *file, int opts) {
 
 	if (opts & R_CORE_PRJ_FLAGS) {
 		r_str_write (fd, "# flags\n");
-		tmp = core->flags->space_idx;
-		core->flags->space_idx = -1;
+		r_flag_space_push (core->flags, NULL);
 		r_flag_list (core->flags, true, NULL);
-		core->flags->space_idx = tmp;
+		r_flag_space_pop (core->flags);
 		r_cons_flush ();
 	}
 	// Set file.path and file.lastpath to empty string to signal
diff --git a/libr/core/visual.c b/libr/core/visual.c
index 00812674e1..ae6d3ff0ff 100644
--- a/libr/core/visual.c
+++ b/libr/core/visual.c
@@ -3512,24 +3512,15 @@ R_API void r_core_visual_title(RCore *core, int color) {
 	filename = desc? desc->name: "";
 	{ /* get flag with delta */
 		ut64 addr = core->offset + (core->print->cur_enabled? core->print->cur: 0);
-#if 1
 		/* TODO: we need a helper into r_flags to do that */
-		bool oss = core->flags->space_strict;
-		int osi = core->flags->space_idx;
 		RFlagItem *f = NULL;
-		core->flags->space_strict = true;
-		core->anal->flb.set_fs (core->flags, "symbols");
-		if (core->flags->space_idx != -1) {
+		if (core->anal->flb.push_fs (core->flags, "symbols")) {
 			f = core->anal->flb.get_at (core->flags, addr, showDelta);
+			core->anal->flb.pop_fs (core->flags);
 		}
-		core->flags->space_strict = oss;
-		core->flags->space_idx = osi;
 		if (!f) {
 			f = r_flag_get_at (core->flags, addr, showDelta);
 		}
-#else
-		RFlagItem *f = r_flag_get_at (core->flags, addr, false);
-#endif
 		if (f) {
 			if (f->offset == addr || !f->offset) {
 				snprintf (pos, sizeof (pos), "@ %s", f->name);
diff --git a/libr/core/vmenus.c b/libr/core/vmenus.c
index f40fdfadd0..980dbadf29 100644
--- a/libr/core/vmenus.c
+++ b/libr/core/vmenus.c
@@ -595,7 +595,7 @@ static int sdbforcb (void *p, const char *k, const char *v) {
 
 R_API int r_core_visual_types(RCore *core) {
 	RCoreVisualTypes vt = {core, 0, 0};
-	int i, j, ch;
+	int i, ch;
 	int _option = 0;
 	int option = 0;
 	char *txt;
@@ -612,12 +612,7 @@ R_API int r_core_visual_types(RCore *core) {
 		NULL
 	};
 	bool use_color = core->print->flags & R_PRINT_FLAGS_COLOR;
-	for (j = i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (core->flags->spaces[i]) {
-			j = 1;
-		}
-	}
-	if (j == 0) {
+	if (r_flag_space_is_empty (core->flags)) {
 		menu = 1;
 	}
 	for (;;) {
@@ -716,12 +711,7 @@ R_API int r_core_visual_types(RCore *core) {
 			option = _option;
 			if (menu==0) {
 				// if no flagspaces, just quit
-				for (j = i = 0; i < R_FLAG_SPACES_MAX; i++) {
-					if (core->flags->spaces[i]) {
-						j = 1;
-					}
-				}
-				if (!j) {
+				if (r_flag_space_is_empty (core->flags)) {
 					return true;
 				}
 			}
@@ -1518,12 +1508,7 @@ R_API int r_core_visual_trackflags(RCore *core) {
 	int menu = 0;
 	int sort = SORT_NONE;
 
-	for (j=i=0; i<R_FLAG_SPACES_MAX; i++) {
-		if (core->flags->spaces[i]) {
-			j = 1;
-		}
-	}
-	if (j == 0) {
+	if (r_flag_space_is_empty (core->flags)) {
 		menu = 1;
 	}
 	for (;;) {
@@ -1532,19 +1517,14 @@ R_API int r_core_visual_trackflags(RCore *core) {
 
 		if (menu) {
 			r_cons_printf ("Flags in flagspace '%s'. Press '?' for help.\n\n",
-			(core->flags->space_idx==-1)?"*":core->flags->spaces[core->flags->space_idx]);
+				r_flag_space_cur_name (core->flags));
 			hit = 0;
 			i = j = 0;
-			RList *l = r_flag_all_list (core->flags);
+			RList *l = r_flag_all_list (core->flags, true);
 			RListIter *iter;
 			RFlagItem *fi;
 			sort_flags (l, sort);
 			r_list_foreach (l, iter, fi) {
-				/* filter per flag spaces */
-				if ((core->flags->space_idx != -1) &&
-				    (fi->space != core->flags->space_idx)) {
-					continue;
-				}
 				if (option == i) {
 					fs2 = fi->name;
 					hit = 1;
@@ -1591,34 +1571,32 @@ R_API int r_core_visual_trackflags(RCore *core) {
 		} else {
 			r_cons_printf ("Flag spaces:\n\n");
 			hit = 0;
-			for (j=i=0;i<R_FLAG_SPACES_MAX;i++) {
-				if (core->flags->spaces[i]) {
-					if (option == i) {
-						fs = core->flags->spaces[i];
-						hit = 1;
-					}
-					if ((i >= option - delta) && ((i < option + delta)|| \
-							((option < delta) && (i < (delta << 1))))) {
-						r_cons_printf (" %c %02d %c %s\n",
-							(option==i)?'>':' ', j,
-							(i==core->flags->space_idx)?'*':' ',
-							core->flags->spaces[i]);
-						j++;
-					}
-				}
-			}
-			if (core->flags->spaces[9]) {
-				if (option == j) {
-					fs = "*";
+			RSpaceIter it;
+			const RSpace *s, *cur = r_flag_space_cur (core->flags);
+			int i = 0;
+			r_flag_space_foreach (core->flags, it, s) {
+				if (option == i) {
+					fs = s->name;
 					hit = 1;
 				}
-				r_cons_printf (" %c %02d %c %s\n",
-					(option==j)?'>':' ', j,
-					(i==core->flags->space_idx)?'*':' ',
-					"*");
+				if ((i >= option - delta) && ((i < option + delta) ||
+					((option < delta) && (i < (delta << 1))))) {
+					r_cons_printf (" %c %c %s\n",
+						(option == i)? '>': ' ',
+						(s == cur)? '*': ' ',
+						s->name);
+				}
+				i++;
 			}
-			if (!hit && j > 0) {
-				option = j - 1;
+			if (option == i) {
+				fs = "*";
+				hit = 1;
+			}
+			r_cons_printf (" %c %c %s\n", (option == i)? '>': ' ',
+				!cur? '*': ' ', "*");
+			i++;
+			if (!hit && i > 0) {
+				option = i - 1;
 				continue;
 			}
 		}
@@ -1663,12 +1641,7 @@ R_API int r_core_visual_trackflags(RCore *core) {
 			if (menu == 0) {
 				r_flag_space_set (core->flags, NULL);
 				// if no flagspaces, just quit
-				for (j=i=0;i<R_FLAG_SPACES_MAX;i++) {
-					if (core->flags->spaces[i]) {
-						j = 1;
-					}
-				}
-				if (!j) {
+				if (r_flag_space_is_empty (core->flags)) {
 					return true;
 				}
 			}
diff --git a/libr/flag/Makefile b/libr/flag/Makefile
index ea3a6692ba..1dbedbbcea 100644
--- a/libr/flag/Makefile
+++ b/libr/flag/Makefile
@@ -2,6 +2,6 @@ include ../config.mk
 
 NAME=r_flag
 DEPS=r_util
-OBJS=flag.o spaces.o zones.o tags.o
+OBJS=flag.o zones.o tags.o
 
 include ../rules.mk
diff --git a/libr/flag/flag.c b/libr/flag/flag.c
index ef72941ef7..a23b04174a 100644
--- a/libr/flag/flag.c
+++ b/libr/flag/flag.c
@@ -7,8 +7,8 @@
 
 R_LIB_VERSION(r_flag);
 
-#define IS_FI_NOTIN_SPACE(f, i) ((f)->space_idx != -1 && (i)->space != (f)->space_idx)
-#define IS_FI_IN_SPACE(fi, spidx) ((spidx) == -1 || (fi)->space == (spidx))
+#define IS_FI_NOTIN_SPACE(f, i) (r_flag_space_cur (f) && (i)->space != r_flag_space_cur (f))
+#define IS_FI_IN_SPACE(fi, sp) (!(sp) || (fi)->space == (sp))
 #define STRDUP_OR_NULL(s) (!R_STR_ISEMPTY (s)? strdup (s): NULL)
 
 static const char *str_callback(RNum *user, ut64 off, int *ok) {
@@ -190,8 +190,38 @@ static void ht_free_flag(HtPPKv *kv) {
 	r_flag_item_free (kv->value);
 }
 
+static bool count_flags(RFlagItem *fi, void *user) {
+	int *count = (int *)user;
+	(*count)++;
+	return true;
+}
+
+static bool unset_flags_space(RFlagItem *fi, void *user) {
+	fi->space = NULL;
+	return true;
+}
+
+static void count_flags_in_space(REvent *ev, int type, void *user, void *data) {
+	RSpaces *sp = (RSpaces *)user;
+	RFlag *f = container_of (sp, RFlag, spaces);
+	RSpaceEvent *spe = (RSpaceEvent *)data;
+	r_flag_foreach_space (f, spe->data.count.space, count_flags, &spe->res);
+}
+
+static void unset_flagspace(REvent *ev, int type, void *user, void *data) {
+	RSpaces *sp = (RSpaces *)user;
+	RFlag *f = container_of (sp, RFlag, spaces);
+	const RSpaceEvent *spe = (const RSpaceEvent *)data;
+	r_flag_foreach_space (f, spe->data.unset.space, unset_flags_space, NULL);
+}
+
+static void new_spaces(RFlag *f) {
+	r_spaces_init (&f->spaces, "fs");
+	r_event_hook (f->spaces.event, R_SPACE_EVENT_COUNT, count_flags_in_space);
+	r_event_hook (f->spaces.event, R_SPACE_EVENT_UNSET, unset_flagspace);
+}
+
 R_API RFlag *r_flag_new() {
-	int i;
 	RFlag *f = R_NEW0 (RFlag);
 	if (!f) {
 		return NULL;
@@ -209,12 +239,6 @@ R_API RFlag *r_flag_new() {
 	f->zones = NULL;
 #endif
 	f->tags = sdb_new0 ();
-	f->space_idx = -1;
-	f->spacestack = r_list_newf (NULL);
-	if (!f->spacestack) {
-		r_flag_free (f);
-		return NULL;
-	}
 	f->ht_name = ht_pp_new (NULL, ht_free_flag, NULL);
 	f->by_off = r_skiplist_new (flag_skiplist_free, flag_skiplist_cmp);
 #if R_FLAG_ZONE_USE_SDB
@@ -222,9 +246,7 @@ R_API RFlag *r_flag_new() {
 #else
 	r_list_free (f->zones);
 #endif
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		f->spaces[i] = NULL;
-	}
+	new_spaces(f);
 	return f;
 }
 
@@ -261,15 +283,10 @@ R_API void r_flag_item_free(RFlagItem *item) {
 
 R_API RFlag *r_flag_free(RFlag *f) {
 	r_return_val_if_fail (f, NULL);
-	int i;
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		free (f->spaces[i]);
-	}
 	r_skiplist_free (f->by_off);
 	ht_pp_free (f->ht_name);
-
 	sdb_free (f->tags);
-	r_list_free (f->spacestack);
+	r_spaces_fini (&f->spaces);
 	r_num_free (f->num);
 	free (f);
 	return NULL;
@@ -287,7 +304,7 @@ struct print_flag_t {
 	bool in_range;
 	ut64 range_from;
 	ut64 range_to;
-	int fs;
+	RSpace *fs;
 	bool real;
 	const char *pfx;
 };
@@ -317,13 +334,9 @@ static bool print_flag_rad(RFlagItem *flag, void *user) {
 	if (u->in_range && (flag->offset < u->range_from || flag->offset >= u->range_to)) {
 		return true;
 	}
-	if (u->fs == -1 || flag->space != u->fs) {
+	if (!u->fs || flag->space != u->fs) {
 		u->fs = flag->space;
-		const char *flagspace = r_flag_space_get_i (u->f, u->fs);
-		if (!flagspace || !*flagspace) {
-			flagspace = "*";
-		}
-		u->f->cb_printf ("fs %s\n", flagspace);
+		u->f->cb_printf ("fs %s\n", u->fs? u->fs->name: "*");
 	}
 	if (flag->alias) {
 		u->f->cb_printf ("fa %s %s\n", flag->name, flag->alias);
@@ -360,7 +373,6 @@ R_API void r_flag_list(RFlag *f, int rad, const char *pfx) {
 	bool in_range = false;
 	ut64 range_from = UT64_MAX;
 	ut64 range_to = UT64_MAX;
-	int fs = -1;
 	if (rad == 'i') {
 		char *sp, *arg = strdup (pfx + 1);
 		sp = strchr (arg,  ' ');
@@ -385,7 +397,7 @@ R_API void r_flag_list(RFlag *f, int rad, const char *pfx) {
 
 	switch (rad) {
 	case 'q':
-		r_flag_foreach_space (f, f->space_idx, print_flag_name, f);
+		r_flag_foreach_space (f, r_flag_space_cur (f), print_flag_name, f);
 		break;
 	case 'j': {
 		PJ *pj = pj_new ();
@@ -398,7 +410,7 @@ R_API void r_flag_list(RFlag *f, int rad, const char *pfx) {
 			.real = false
 		};
 		pj_a (pj);
-		r_flag_foreach_space (f, f->space_idx, print_flag_json, &u);
+		r_flag_foreach_space (f, r_flag_space_cur (f), print_flag_json, &u);
 		pj_end (pj);
 		f->cb_printf ("%s\n", pj_string (pj));
 		pj_free (pj);
@@ -411,10 +423,10 @@ R_API void r_flag_list(RFlag *f, int rad, const char *pfx) {
 			.in_range = in_range,
 			.range_from = range_from,
 			.range_to = range_to,
-			.fs = fs,
+			.fs = NULL,
 			.pfx = pfx
 		};
-		r_flag_foreach_space (f, f->space_idx, print_flag_rad, &u);
+		r_flag_foreach_space (f, r_flag_space_cur (f), print_flag_rad, &u);
 		break;
 	}
 	default:
@@ -427,7 +439,7 @@ R_API void r_flag_list(RFlag *f, int rad, const char *pfx) {
 				.range_to = range_to,
 				.real = (rad == 'n')
 			};
-			r_flag_foreach_space (f, f->space_idx, print_flag_orig_name, &u);
+			r_flag_foreach_space (f, r_flag_space_cur (f), print_flag_orig_name, &u);
 		} else {
 			PJ *pj = pj_new ();
 			struct print_flag_t u = {
@@ -439,7 +451,7 @@ R_API void r_flag_list(RFlag *f, int rad, const char *pfx) {
 				.real = true
 			};
 			pj_a (pj);
-			r_flag_foreach_space (f, f->space_idx, print_flag_json, &u);
+			r_flag_foreach_space (f, r_flag_space_cur (f), print_flag_json, &u);
 			pj_end (pj);
 			f->cb_printf ("%s\n", pj_string (pj));
 			pj_free (pj);
@@ -554,7 +566,7 @@ R_API RFlagItem *r_flag_get_at(RFlag *f, ut64 off, bool closest) {
 	}
 	if (flags_at->off == off) {
 		r_list_foreach (flags_at->flags, iter, item) {
-			if (f->space_idx != -1 && item->space != f->space_idx) {
+			if (IS_FI_NOTIN_SPACE (f, item)) {
 				continue;
 			}
 			if (nice) {
@@ -573,7 +585,7 @@ R_API RFlagItem *r_flag_get_at(RFlag *f, ut64 off, bool closest) {
 	}
 	while (!nice && flags_at) {
 		r_list_foreach (flags_at->flags, iter, item) {
-			if (f->space_strict && IS_FI_NOTIN_SPACE (f, item)) {
+			if (IS_FI_NOTIN_SPACE (f, item)) {
 				continue;
 			}
 			if (item->offset == off) {
@@ -592,17 +604,20 @@ R_API RFlagItem *r_flag_get_at(RFlag *f, ut64 off, bool closest) {
 	return nice? evalFlag (f, nice): NULL;
 }
 
-static bool append_to_list(void *user, const void *k, const void *v) {
+static bool append_to_list(RFlagItem *fi, void *user) {
 	RList *ret = (RList *)user;
-	r_list_append (ret, (RFlagItem *)v);
+	r_list_append (ret, fi);
 	return true;
 }
 
-R_API RList *r_flag_all_list(RFlag *f) {
+R_API RList *r_flag_all_list(RFlag *f, bool by_space) {
 	RList *ret = r_list_new ();
-	if (ret) {
-		ht_pp_foreach (f->ht_name, append_to_list, ret);
+	if (!ret) {
+		return NULL;
 	}
+
+	RSpace *cur = by_space? r_flag_space_cur (f): NULL;
+	r_flag_foreach_space (f, cur, append_to_list, ret);
 	return ret;
 }
 
@@ -676,7 +691,7 @@ R_API RFlagItem *r_flag_set(RFlag *f, const char *name, ut64 off, ut32 size) {
 		}
 	}
 
-	item->space = f->space_idx;
+	item->space = r_flag_space_cur (f);
 	item->size = size;
 
 	update_flag_item_offset (f, item, off + f->base, true);
@@ -774,11 +789,11 @@ R_API bool r_flag_unset_name(RFlag *f, const char *name) {
 /* unset all flag items in the RFlag f */
 R_API void r_flag_unset_all(RFlag *f) {
 	r_return_if_fail (f);
-	f->space_idx = -1;
 	ht_pp_free (f->ht_name);
 	f->ht_name = ht_pp_new (NULL, ht_free_flag, NULL);
 	r_skiplist_purge (f->by_off);
-	r_flag_space_unset (f, NULL);
+	r_spaces_fini (&f->spaces);
+	new_spaces (f);
 }
 
 struct flag_relocate_t {
@@ -900,6 +915,6 @@ R_API void r_flag_foreach_glob(RFlag *f, const char *glob, RFlagItemCb cb, void
 	FOREACH_BODY (!glob || r_str_glob (fi->name, glob));
 }
 
-R_API void r_flag_foreach_space(RFlag *f, int space, RFlagItemCb cb, void *user) {
+R_API void r_flag_foreach_space(RFlag *f, const RSpace *space, RFlagItemCb cb, void *user) {
 	FOREACH_BODY (IS_FI_IN_SPACE (fi, space));
 }
diff --git a/libr/flag/meson.build b/libr/flag/meson.build
index 43ac7418e4..09efa6e781 100644
--- a/libr/flag/meson.build
+++ b/libr/flag/meson.build
@@ -1,7 +1,6 @@
 r_flag_sources = [
   'flag.c',
   'tags.c',
-  'spaces.c',
   'zones.c'
 ]
 
diff --git a/libr/flag/spaces.c b/libr/flag/spaces.c
deleted file mode 100644
index 90af8a0be6..0000000000
--- a/libr/flag/spaces.c
+++ /dev/null
@@ -1,252 +0,0 @@
-/* radare - LGPL - Copyright 2008-2016 - pancake */
-
-#include <r_flag.h>
-#include <r_cons.h>
-
-R_API int r_flag_space_get(RFlag *f, const char *name) {
-	int i;
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (f->spaces[i] != NULL) {
-			if (!strcmp (name, f->spaces[i])) {
-				return i;
-			}
-		}
-	}	
-	return -1;
-}
-
-R_API const char *r_flag_space_get_i(RFlag *f, int idx) {
-	if (idx == -1 || idx >= R_FLAG_SPACES_MAX || !f || !f->spaces[idx] || !*f->spaces[idx]) {
-		return "";
-	}
-	return f->spaces[idx];
-}
-
-R_API const char *r_flag_space_cur(RFlag *f) {
-	r_return_val_if_fail (f, NULL);
-	return r_flag_space_get_i (f, f->space_idx);
-}
-
-R_API bool r_flag_space_push(RFlag *f, const char *name) {
-	r_return_val_if_fail (f && name, false);
-	if (f->space_idx != -1 && f->spaces[f->space_idx]) {
-		r_list_push (f->spacestack, f->spaces[f->space_idx]);
-	} else {
-		r_list_push (f->spacestack, "*");
-	}
-	r_flag_space_set (f, name);
-	return true;
-}
-
-R_API bool r_flag_space_pop(RFlag *f) {
-	r_return_val_if_fail (f, false);
-	char *p = r_list_pop (f->spacestack);
-	if (p) {
-		if (*p) {
-			r_flag_space_set (f, p);
-		}
-		return true;
-	}
-	return false;
-}
-
-R_API bool r_flag_space_set_i(RFlag *f, int idx) {
-	int i;
-	r_return_val_if_fail (f, false);
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (f->spaces[i]) {
-			f->space_idx = idx;
-			return true;
-		}
-	}
-	return false;
-}
-
-R_API int r_flag_space_set(RFlag *f, const char *name) {
-	int i;
-	if (!name || !*name || *name == '*') {
-		f->space_idx = -1;
-		return f->space_idx;
-	}
-	if (f->space_idx != -1) {
-		if (!strcmp (name, f->spaces[f->space_idx])) {
-			return f->space_idx;
-		}
-	}
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (f->spaces[i] && !strcmp (name, f->spaces[i])) {
-			f->space_idx = i;
-			return f->space_idx;
-		}
-	}
-	/* not found */
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (!f->spaces[i]) {
-			f->spaces[i] = strdup (name);
-			f->space_idx = i;
-			break;
-		}
-	}
-	return f->space_idx;
-}
-
-static bool unset_space(RFlagItem *fi, void *user) {
-	fi->space = -1;
-	return true;
-}
-
-R_API int r_flag_space_unset(RFlag *f, const char *fs) {
-	r_return_val_if_fail (f, false);
-	int i, count = 0;
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (!f->spaces[i]) {
-			continue;
-		}
-		if (!fs || !strcmp (fs, f->spaces[i])) {
-			if (f->space_idx == i) {
-				f->space_idx = -1;
-			}
-			R_FREE (f->spaces[i]);
-			// remove all flags space references
-			r_flag_foreach_space (f, i, unset_space, NULL);
-			count++;
-		}
-	}
-	return count;
-}
-
-static bool space_count(RFlagItem *fi, void *user) {
-	int *count = (int *)user;
-	(*count)++;
-	return true;
-}
-
-static int r_flag_space_count(RFlag *f, int n) {
-	int count = 0;
-	if (n != -1) {
-		r_flag_foreach_space (f, n, space_count, &count);
-	}
-	return count;
-}
-
-R_API int r_flag_space_list(RFlag *f, int mode) {
-	r_return_val_if_fail (f, -1);
-	const char *defspace = NULL;
-	int count, len, i, j = 0;
-	bool allSelected = f->space_idx == -1;
-	if (mode == 'j') {
-		f->cb_printf ("[");
-	}
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (!f->spaces[i]) {
-			continue;
-		}
-		count = r_flag_space_count (f, i);
-		if (mode == 'q') {
-			f->cb_printf ("%s\n", f->spaces[i]);
-		} else if (mode == 'j') {
-			f->cb_printf ("%s{\"name\":\"%s\",\"count\":%d,\"selected\":%s}",
-					j? ",":"", f->spaces[i], count,
-					(allSelected || i == f->space_idx)? "true":"false");
-		} else if (mode=='*') {
-			f->cb_printf ("fs %s\n", f->spaces[i]);
-			if (i == f->space_idx) {
-				defspace = f->spaces[i];
-			}
-		} else {
-			#define INDENT 5
-			char num0[64], num1[64], spaces[32];
-			snprintf (num0, sizeof (num0), "%d", i);
-			snprintf (num1, sizeof (num1), "%d", count);
-			memset(spaces, ' ', sizeof (spaces));
-			len = strlen (num0) + strlen (num1);
-			if (len < INDENT) {
-				spaces[INDENT-len] = 0;
-			} else {
-				spaces[0] = 0;
-			}
-			f->cb_printf ("%s%s %s %c %s\n", num0, spaces, num1,
-					(allSelected || i==f->space_idx)?'*':'.',
-					f->spaces[i]);
-		}
-		j++;
-	}
-	if (defspace) {
-		f->cb_printf ("fs %s # current\n", defspace);
-	}
-	if (mode == 'j') {
-		f->cb_printf ("]\n");
-	}
-	return j;
-}
-
-R_API bool r_flag_space_rename (RFlag *f, const char *oname, const char *nname) {
-	int i;
-	r_return_val_if_fail (f && nname, false);
-	if (!oname) {
-		if (f->space_idx == -1) {
-			return false;
-		}
-		oname = f->spaces[f->space_idx];
-	}
-	oname = r_str_trim_ro (oname);
-	nname = r_str_trim_ro (nname);
-	for (i = 0; i < R_FLAG_SPACES_MAX; i++) {
-		if (f->spaces[i]  && !strcmp (oname, f->spaces[i])) {
-			free (f->spaces[i]);
-			f->spaces[i] = strdup (nname);
-			return true;
-		}
-	}
-	return false;
-}
-
-static void print_space_stack(RFlag *f, int ordinal, char *name, bool selected, int mode) {
-	bool first = ordinal == 0;
-	switch (mode) {
-	case 'j':
-		if (!first) {
-			f->cb_printf (",");
-		}
-		{
-		char *ename = r_str_escape (name);
-		f->cb_printf ("{\"ordinal\":%d,\"name\":\"%s\",\"selected\":%s}",
-			ordinal, ename, selected? "true":"false");
-		free (ename);
-		}
-		break;
-	case '*':
-		if (first) {
-			f->cb_printf ("fs %s\n", name);
-		} else {
-			f->cb_printf ("fs+%s\n", name);
-		}
-		break;
-	default:
-		f->cb_printf ("%-2d %s%s\n", ordinal, name, selected? " (selected)":"");
-		break;
-	}
-}
-
-R_API int r_flag_space_stack_list(RFlag *f, int mode) {
-	RListIter *iter;
-	char *space;
-	int i = 0;
-	if (mode == 'j') {
-		f->cb_printf ("[");
-	}
-	r_list_foreach (f->spacestack, iter, space) {
-		print_space_stack (f, i++, space, false, mode);
-	}
-	if (f->space_idx == -1) {
-		print_space_stack (f, i++, "*", true, mode);
-	} else {
-		if (f->spaces[f->space_idx]) {
-			print_space_stack (f, i++, f->spaces[f->space_idx], true, mode);
-		}
-	}
-	if (mode == 'j') {
-		f->cb_printf ("]\n");
-	}
-	return i;
-}
diff --git a/libr/include/r_flag.h b/libr/include/r_flag.h
index 411500c01d..12d55f0adb 100644
--- a/libr/include/r_flag.h
+++ b/libr/include/r_flag.h
@@ -14,7 +14,6 @@ extern "C" {
 R_LIB_VERSION_HEADER(r_flag);
 
 #define R_FLAG_NAME_SIZE 512
-#define R_FLAG_SPACES_MAX 128
 
 /* zones.c */
 
@@ -42,23 +41,20 @@ typedef struct r_flag_item_t {
 	char *realname; /* real name, without any escaping */
 	ut64 offset;    /* offset flagged by this item */
 	ut64 size;      /* size of the flag item */
-	int space;      /* flag space this item belongs to */
+	RSpace *space;  /* flag space this item belongs to */
 	char *color;    /* item color */
 	char *comment;  /* item comment */
 	char *alias;    /* used to define a flag based on a math expression (e.g. foo + 3) */
 } RFlagItem;
 
 typedef struct r_flag_t {
+	RSpaces spaces;   /* handle flag spaces */
 	st64 base;         /* base address for all flag items */
-	int space_idx;     /* index of the selected space in spaces array */
-	bool space_strict; /* when true returned flag items must belong to the selected space */
 	bool realnames;
-	char *spaces[R_FLAG_SPACES_MAX]; /* array of flag spaces */
 	Sdb *tags;
 	RNum *num;
 	RSkipList *by_off; /* flags sorted by offset, value=RFlagsAtOffset */
 	HtPP *ht_name; /* hashmap key=item name, value=RList of items */
-	RList *spacestack;
 	PrintfCallback cb_printf;
 #if R_FLAG_ZONE_USE_SDB
 	Sdb *zones;
@@ -76,7 +72,7 @@ typedef RFlagItem* (*RFlagSet)(RFlag *f, const char *name, ut64 addr, ut32 size)
 typedef bool (*RFlagUnset)(RFlag *f, RFlagItem *item);
 typedef bool (*RFlagUnsetName)(RFlag *f, const char *name);
 typedef bool (*RFlagUnsetOff)(RFlag *f, ut64 addr);
-typedef int (*RFlagSetSpace)(RFlag *f, const char *name);
+typedef RSpace *(*RFlagSetSpace)(RFlag *f, const char *name);
 typedef bool (*RFlagPopSpace)(RFlag *f);
 typedef bool (*RFlagPushSpace)(RFlag *f, const char *name);
 
@@ -109,7 +105,7 @@ R_API RFlagItem *r_flag_get(RFlag *f, const char *name);
 R_API RFlagItem *r_flag_get_i(RFlag *f, ut64 off);
 R_API RFlagItem *r_flag_get_i2(RFlag *f, ut64 off);
 R_API RFlagItem *r_flag_get_at(RFlag *f, ut64 off, bool closest);
-R_API RList *r_flag_all_list(RFlag *f);
+R_API RList *r_flag_all_list(RFlag *f, bool by_space);
 R_API const RList* /*<RFlagItem*>*/ r_flag_get_list(RFlag *f, ut64 off);
 R_API char *r_flag_get_liststr(RFlag *f, ut64 off);
 R_API bool r_flag_unset(RFlag *f, RFlagItem *item);
@@ -128,25 +124,55 @@ R_API int r_flag_rename(RFlag *f, RFlagItem *item, const char *name);
 R_API int r_flag_relocate(RFlag *f, ut64 off, ut64 off_mask, ut64 to);
 R_API bool r_flag_move (RFlag *f, ut64 at, ut64 to);
 R_API const char *r_flag_color(RFlag *f, RFlagItem *it, const char *color);
+R_API int r_flag_count(RFlag *f, const char *glob);
 R_API void r_flag_foreach(RFlag *f, RFlagItemCb cb, void *user);
 R_API void r_flag_foreach_prefix(RFlag *f, const char *pfx, int pfx_len, RFlagItemCb cb, void *user);
 R_API void r_flag_foreach_range(RFlag *f, ut64 from, ut64 to, RFlagItemCb cb, void *user);
 R_API void r_flag_foreach_glob(RFlag *f, const char *glob, RFlagItemCb cb, void *user);
-R_API void r_flag_foreach_space(RFlag *f, int space, RFlagItemCb cb, void *user);
+R_API void r_flag_foreach_space(RFlag *f, const RSpace *space, RFlagItemCb cb, void *user);
 
 /* spaces */
-R_API int r_flag_space_get(RFlag *f, const char *name);
-R_API const char *r_flag_space_get_i(RFlag *f, int idx);
-R_API const char *r_flag_space_cur(RFlag *f);
-R_API int r_flag_space_set(RFlag *f, const char *name);
-R_API bool r_flag_space_set_i(RFlag *f, int idx);
-R_API int r_flag_count(RFlag *f, const char *name);
-R_API int r_flag_space_unset(RFlag *f, const char *fs);
-R_API int r_flag_space_list(RFlag *f, int mode);
-R_API bool r_flag_space_rename(RFlag *f, const char *oname, const char *nname);
-R_API bool r_flag_space_pop(RFlag *f);
-R_API bool r_flag_space_push(RFlag *f, const char *name);
-R_API int r_flag_space_stack_list(RFlag *f, int mode);
+static inline RSpace *r_flag_space_get(RFlag *f, const char *name) {
+	return r_spaces_get (&f->spaces, name);
+}
+
+static inline RSpace *r_flag_space_cur(RFlag *f) {
+	return r_spaces_current (&f->spaces);
+}
+
+static inline const char *r_flag_space_cur_name(RFlag *f) {
+	return r_spaces_current_name (&f->spaces);
+}
+
+static inline RSpace *r_flag_space_set(RFlag *f, const char *name) {
+	return r_spaces_set (&f->spaces, name);
+}
+
+static inline bool r_flag_space_unset(RFlag *f, const char *name) {
+	return r_spaces_unset (&f->spaces, name);
+}
+
+static inline bool r_flag_space_rename(RFlag *f, const char *oname, const char *nname) {
+	return r_spaces_rename (&f->spaces, oname, nname);
+}
+
+static inline bool r_flag_space_push(RFlag *f, const char *name) {
+	return r_spaces_push (&f->spaces, name);
+}
+
+static inline bool r_flag_space_pop(RFlag *f) {
+	return r_spaces_pop (&f->spaces);
+}
+
+static inline int r_flag_space_count(RFlag *f, const char *name) {
+	return r_spaces_count (&f->spaces, name);
+}
+
+static inline bool r_flag_space_is_empty(RFlag *f) {
+	return r_spaces_is_empty (&f->spaces);
+}
+
+#define r_flag_space_foreach(f, it, s) r_spaces_foreach (&(f)->spaces, (it), (s))
 
 /* tags */
 R_API RList *r_flag_tags_list(RFlag *f);
diff --git a/libr/include/r_parse.h b/libr/include/r_parse.h
index 96887953cd..e450fbb2c7 100644
--- a/libr/include/r_parse.h
+++ b/libr/include/r_parse.h
@@ -20,8 +20,8 @@ typedef RList* (*RAnalVarList)(RAnal *anal, RAnalFunction *fcn, int kind);
 
 typedef struct r_parse_t {
 	void *user;
-	int flagspace;
-	int notin_flagspace;
+	RSpace *flagspace;
+	RSpace *notin_flagspace;
 	bool pseudo;
 	bool relsub; // replace rip relative expressions in instruction
 	bool tailsub; // replace any immediate relative to current address with .. prefix syntax
diff --git a/libr/include/r_util/r_spaces.h b/libr/include/r_util/r_spaces.h
index d25c8a2725..fc107ca871 100644
--- a/libr/include/r_util/r_spaces.h
+++ b/libr/include/r_util/r_spaces.h
@@ -73,7 +73,7 @@ R_API RSpace *r_spaces_get(RSpaces *sp, const char *name);
 R_API RSpace *r_spaces_add(RSpaces *sp, const char *name);
 // Add and select a new RSpace if one does not already exist, otherwise return and select the existing one
 R_API RSpace *r_spaces_set(RSpaces *sp, const char *name);
-// Remove the RSpace with the given name
+// Remove the RSpace with the given name or all of them if name is NULL
 R_API bool r_spaces_unset(RSpaces *sp, const char *name);
 // Change the name of RSpace with oname to nname
 R_API bool r_spaces_rename(RSpaces *sp, const char *oname, const char *nname);
@@ -92,6 +92,15 @@ static inline const char *r_spaces_current_name(RSpaces *sp) {
 	return sp->current? sp->current->name: "*";
 }
 
+static inline bool r_spaces_is_empty(RSpaces *sp) {
+	RBIter it = r_rbtree_first (sp->spaces);
+	return it.len == 0;
+}
+
+typedef RBIter RSpaceIter;
+#define r_spaces_foreach(sp, it, s) \
+	r_rbtree_foreach ((sp)->spaces, (it), (s), RSpace, rb)
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/libr/parse/parse.c b/libr/parse/parse.c
index cde13f14b4..b1562eb394 100644
--- a/libr/parse/parse.c
+++ b/libr/parse/parse.c
@@ -23,8 +23,8 @@ R_API RParse *r_parse_new() {
 		return NULL;
 	}
 	p->parsers->free = NULL; // memleak
-	p->notin_flagspace = -1;
-	p->flagspace = -1;
+	p->notin_flagspace = NULL;
+	p->flagspace = NULL;
 	p->pseudo = false;
 	p->relsub = false;
 	p->tailsub = false;
@@ -275,11 +275,11 @@ static int filter(RParse *p, ut64 addr, RFlag *f, char *data, char *str, int len
 					}
 				}
 				if (isvalidflag (flag)) {
-					if (p->notin_flagspace != -1) {
+					if (p->notin_flagspace) {
 						if (p->flagspace == flag->space) {
 							continue;
 						}
-					} else if (p->flagspace != -1 && (p->flagspace != flag->space)) {
+					} else if (p->flagspace && (p->flagspace != flag->space)) {
 						ptr = ptr2;
 						continue;
 					}
@@ -588,10 +588,6 @@ R_API void r_parse_set_user_ptr(RParse *p, void *user) {
 	p->user = user;
 }
 
-R_API void r_parse_set_flagspace(RParse *p, int fs) {
-	p->flagspace = fs;
-}
-
 /* TODO: DEPRECATE */
 R_API int r_parse_list(RParse *p) {
 	RListIter *iter;
diff --git a/libr/util/spaces.c b/libr/util/spaces.c
index 4d425d4b96..cfd1d123df 100644
--- a/libr/util/spaces.c
+++ b/libr/util/spaces.c
@@ -69,6 +69,9 @@ static int name_space_cmp(const void *incoming, const RBNode *rb) {
 }
 
 R_API RSpace *r_spaces_get(RSpaces *sp, const char *name) {
+	if (!name) {
+		return NULL;
+	}
 	RBNode *n = r_rbtree_find (sp->spaces, (void *)name, name_space_cmp);
 	return n? container_of (n, RSpace, rb): NULL;
 }
@@ -110,7 +113,7 @@ R_API RSpace *r_spaces_set(RSpaces *sp, const char *name) {
 	return sp->current;
 }
 
-R_API bool r_spaces_unset(RSpaces *sp, const char *name) {
+static bool spaces_unset_single(RSpaces *sp, const char *name) {
 	RSpace *space = r_spaces_get (sp, name);
 	if (!space) {
 		return false;
@@ -121,6 +124,32 @@ R_API bool r_spaces_unset(RSpaces *sp, const char *name) {
 	return r_rbtree_delete (&sp->spaces, (void *)name, name_space_cmp, space_node_free);
 }
 
+R_API bool r_spaces_unset(RSpaces *sp, const char *name) {
+	if (name) {
+		return spaces_unset_single (sp, name);
+	}
+
+	RList *names = r_list_newf ((RListFree)free);
+	if (!names) {
+		return false;
+	}
+
+	RBIter it;
+	RSpace *s;
+	r_spaces_foreach (sp, it, s) {
+		r_list_append (names, strdup (s->name));
+	}
+
+	RListIter *lit;
+	const char *n;
+	bool res = false;
+	r_list_foreach (names, lit, n) {
+		res |= spaces_unset_single (sp, n);
+	}
+	r_list_free (names);
+	return res;
+}
+
 R_API int r_spaces_count(RSpaces *sp, const char *name) {
 	RSpace *s = r_spaces_get (sp, name);
 	if (!s) {