From 97f3bb57b1e613aedd97cb941ed436001692a1c1 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Marc=20Andr=C3=A9=20Tanner?= <mat@brain-dump.org>
Date: Thu, 15 Jun 2017 13:15:57 +0200
Subject: [PATCH] vis: implement pairwise selection combinator: union

---
 main.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 vis.h  |  1 +
 2 files changed, 43 insertions(+)

diff --git a/main.c b/main.c
index 3253a220e..e9df2c39f 100644
--- a/main.c
+++ b/main.c
@@ -86,6 +86,9 @@ static const char *selections_intersect(Vis*, const char *keys, const Arg *arg);
 static const char *selections_complement(Vis*, const char *keys, const Arg *arg);
 /* subtract selections from register */
 static const char *selections_minus(Vis*, const char *keys, const Arg *arg);
+/* pariwise combine selections */
+static const char *selections_combine(Vis*, const char *keys, const Arg *arg);
+static Filerange combine_union(const Filerange*, const Filerange*);
 /* adjust current used count according to keys */
 static const char *count(Vis*, const char *keys, const Arg *arg);
 /* move to the count-th line or if not given either to the first (arg->i < 0)
@@ -294,6 +297,7 @@ enum {
 	VIS_ACTION_SELECTIONS_INTERSECT,
 	VIS_ACTION_SELECTIONS_COMPLEMENT,
 	VIS_ACTION_SELECTIONS_MINUS,
+	VIS_ACTION_SELECTIONS_COMBINE_UNION,
 	VIS_ACTION_TEXT_OBJECT_WORD_OUTER,
 	VIS_ACTION_TEXT_OBJECT_WORD_INNER,
 	VIS_ACTION_TEXT_OBJECT_LONGWORD_OUTER,
@@ -1084,6 +1088,11 @@ static const KeyAction vis_action[] = {
 		VIS_HELP("Subtract selections from register")
 		selections_minus
 	},
+	[VIS_ACTION_SELECTIONS_COMBINE_UNION] = {
+		"vis-selections-combine-union",
+		VIS_HELP("Pairwise union with selection from register")
+		selections_combine, { .combine = combine_union }
+	},
 	[VIS_ACTION_TEXT_OBJECT_WORD_OUTER] = {
 		"vis-textobject-word-outer",
 		VIS_HELP("A word leading and trailing whitespace included")
@@ -1789,6 +1798,39 @@ static const char *selections_minus(Vis *vis, const char *keys, const Arg *arg)
 	return keys;
 }
 
+static Filerange combine_union(const Filerange *r1, const Filerange *r2) {
+	if (!r1)
+		return *r2;
+	if (!r2)
+		return *r1;
+	return text_range_union(r1, r2);
+}
+
+static const char *selections_combine(Vis *vis, const char *keys, const Arg *arg) {
+	View *view = vis_view(vis);
+	enum VisRegister reg = vis_register_used(vis);
+	Array a = view_selections_get_all(view);
+	Array b = vis_register_selections_get(vis, reg);
+	Array sel;
+	array_init_from(&sel, &a);
+
+	Filerange *r1 = array_get(&a, 0), *r2 = array_get(&b, 0);
+	for (size_t i = 0, j = 0; r1 || r2; r1 = array_get(&a, ++i), r2 = array_get(&b, ++j)) {
+		Filerange new = arg->combine(r1, r2);
+		if (text_range_valid(&new))
+			array_add(&sel, &new);
+	}
+
+	view_selections_set_all(view, &sel);
+	vis_cancel(vis);
+
+	array_release(&a);
+	array_release(&b);
+	array_release(&sel);
+
+	return keys;
+}
+
 static const char *replace(Vis *vis, const char *keys, const Arg *arg) {
 	if (!keys[0]) {
 		vis_keymap_disable(vis);
diff --git a/vis.h b/vis.h
index 35e9a26f9..32dce8091 100644
--- a/vis.h
+++ b/vis.h
@@ -67,6 +67,7 @@ typedef union {
 	const void *v;
 	void (*w)(View*);
 	void (*f)(Vis*);
+	Filerange (*combine)(const Filerange*, const Filerange*);
 } Arg;
 
 /**