Add infrastructure to register custom text object functions

vis-core.h

@@ -76,11 +76,13 @@ typedef struct {
 	 * representing the text object containing the position. */
 	Filerange (*txt)(Text*, size_t pos);
 	Filerange (*vis)(Vis*, Text*, size_t pos);
+	Filerange (*user)(Vis*, Win*, void *data, size_t pos);
 	enum {
 		INNER = 1 << 0, /* whether the object should include */
 		OUTER = 1 << 1, /* the delimiting symbols or not */
 		SPLIT = 1 << 2, /* whether multiple applications will yield a split range */
 	} type;
+	void *data;
 } TextObject;
 
 /* a macro is just a sequence of symbolic keys as received from ui->getkey */
@@ -169,6 +171,7 @@ struct Vis {
 	lua_State *lua;                      /* lua context used for syntax highligthing */
 	VisEvent *event;
 	Array motions;
+	Array textobjects;
 };
 
 /** stuff used by multiple of the vis-* files */

vis-text-objects.c

@@ -2,13 +2,32 @@
 #include "text-objects.h"
 #include "util.h"
 
+int vis_textobject_register(Vis *vis, int type, void *data,
+	Filerange (*textobject)(Vis*, Win*, void*, size_t pos)) {
+
+	TextObject *obj = calloc(1, sizeof *obj);
+	if (!obj)
+		return -1;
+
+	obj->user = textobject;
+	obj->type = type;
+	obj->data = data;
+
+	if (array_add(&vis->textobjects, obj))
+		return LENGTH(vis_textobjects) + array_length(&vis->textobjects) - 1;
+	free(obj);
+	return -1;
+}
+
 bool vis_textobject(Vis *vis, enum VisTextObject id) {
-	if (id < LENGTH(vis_textobjects)) {
+	if (id < LENGTH(vis_textobjects))
 		vis->action.textobj = &vis_textobjects[id];
-		action_do(vis, &vis->action);
-		return true;
-	}
-	return false;
+	else
+		vis->action.textobj = array_get(&vis->textobjects, id - LENGTH(vis_textobjects));
+	if (!vis->action.textobj)
+		return false;
+	action_do(vis, &vis->action);
+	return true;
 }
 
 static Filerange search_forward(Vis *vis, Text *txt, size_t pos) {

vis.c

@@ -378,6 +378,7 @@ void vis_free(Vis *vis) {
 	for (int i = 0; i < VIS_MODE_INVALID; i++)
 		map_free(vis_modes[i].bindings);
 	array_release_full(&vis->motions);
+	array_release_full(&vis->textobjects);
 	free(vis);
 }
 
@@ -524,11 +525,13 @@ void action_do(Vis *vis, Action *a) {
 			else
 				c.range.start = c.range.end = pos;
 			for (int i = 0; i < count; i++) {
-				Filerange r;
+				Filerange r = text_range_empty();
 				if (a->textobj->txt)
 					r = a->textobj->txt(txt, pos);
-				else
+				else if (a->textobj->vis)
 					r = a->textobj->vis(vis, txt, pos);
+				else if (a->textobj->user)
+					r = a->textobj->user(vis, win, a->textobj->data, pos);
 				if (!text_range_valid(&r))
 					break;
 				if (a->textobj->type & OUTER) {

vis.h

@@ -317,6 +317,11 @@ enum VisTextObject {
 
 bool vis_textobject(Vis*, enum VisTextObject);
 
+/* register a new text object, if successful the returned id is positive
+ * and can be used as argument for the vis_textobject function. */
+int vis_textobject_register(Vis*, int type, void *data,
+	Filerange (*textobject)(Vis*, Win*, void*, size_t pos));
+
 /* macro REPEAT and INVALID should be considered as implementation details (TODO: hide them?) */
 enum VisMacro {
 	VIS_MACRO_a, VIS_MACRO_b, VIS_MACRO_c, VIS_MACRO_d, VIS_MACRO_e,