vis: implement `gh` and `gl` to move by relative byte offsets

4 files changed, 36 insertions, 0 deletions

diff --git a/config.def.h b/config.def.h
index eb01ac9..1d08434 100644
--- a/config.def.h
+++ b/config.def.h
@@ -66,6 +66,8 @@ static const KeyBinding bindings_motions[] = {
 	{ "F",                  ACTION(TO_LEFT)                             },
 	{ "f",                  ACTION(TO_RIGHT)                            },
 	{ "go",                 ACTION(CURSOR_BYTE)                         },
+	{ "gh",                 ACTION(CURSOR_BYTE_LEFT)                    },
+	{ "gl",                 ACTION(CURSOR_BYTE_RIGHT)                   },
 	{ "g0",                 ACTION(CURSOR_SCREEN_LINE_BEGIN)            },
 	{ "g_",                 ACTION(CURSOR_LINE_FINISH)                  },
 	{ "G",                  ACTION(CURSOR_LINE_LAST)                    },
diff --git a/main.c b/main.c
index 7462e1b..0a8b7bb 100644
--- a/main.c
+++ b/main.c
@@ -161,6 +161,8 @@ enum {
 	VIS_ACTION_CURSOR_SCREEN_LINE_END,
 	VIS_ACTION_CURSOR_PERCENT,
 	VIS_ACTION_CURSOR_BYTE,
+	VIS_ACTION_CURSOR_BYTE_LEFT,
+	VIS_ACTION_CURSOR_BYTE_RIGHT,
 	VIS_ACTION_CURSOR_PARAGRAPH_PREV,
 	VIS_ACTION_CURSOR_PARAGRAPH_NEXT,
 	VIS_ACTION_CURSOR_SENTENCE_PREV,
@@ -457,6 +459,16 @@ static const KeyAction vis_action[] = {
 		"Move to absolute byte position",
 		movement, { .i = VIS_MOVE_BYTE }
 	},
+	[VIS_ACTION_CURSOR_BYTE_LEFT] = {
+		"cursor-byte-left",
+		"Move count bytes to the left",
+		movement, { .i = VIS_MOVE_BYTE_LEFT }
+	},
+	[VIS_ACTION_CURSOR_BYTE_RIGHT] = {
+		"cursor-byte-right",
+		"Move count bytes to the right",
+		movement, { .i = VIS_MOVE_BYTE_RIGHT }
+	},
 	[VIS_ACTION_CURSOR_PARAGRAPH_PREV] = {
 		"cursor-paragraph-prev",
 		"Move cursor paragraph backward",
diff --git a/vis-motions.c b/vis-motions.c
index 1e9d9c5..c6fcc76 100644
--- a/vis-motions.c
+++ b/vis-motions.c
@@ -227,6 +227,18 @@ static size_t byte(Vis *vis, Text *txt, size_t pos) {
 	return pos <= max ? pos : max;
 }
 
+static size_t byte_left(Vis *vis, Text *txt, size_t pos) {
+	size_t off = vis_count_get_default(vis, 1);
+	return off <= pos ? pos-off : 0;
+}
+
+static size_t byte_right(Vis *vis, Text *txt, size_t pos) {
+	size_t off = vis_count_get_default(vis, 1);
+	size_t new = pos + off;
+	size_t max = text_size(txt);
+	return new <= max && new > pos ? new : max;
+}
+
 void vis_motion_type(Vis *vis, enum VisMotionType type) {
 	vis->action.type = type;
 }
@@ -587,4 +599,12 @@ const Movement vis_motions[] = {
 		.vis = byte,
 		.type = IDEMPOTENT,
 	},
+	[VIS_MOVE_BYTE_LEFT] = {
+		.vis = byte_left,
+		.type = IDEMPOTENT,
+	},
+	[VIS_MOVE_BYTE_RIGHT] = {
+		.vis = byte_right,
+		.type = IDEMPOTENT,
+	},
 };
diff --git a/vis.h b/vis.h
index 081ae35..ce6e42b 100644
--- a/vis.h
+++ b/vis.h
@@ -284,6 +284,8 @@ enum VisMotion {
 	VIS_MOVE_NOP,
 	VIS_MOVE_PERCENT,
 	VIS_MOVE_BYTE,
+	VIS_MOVE_BYTE_LEFT,
+	VIS_MOVE_BYTE_RIGHT,
 	VIS_MOVE_INVALID, /* denotes the end of the "real" motions */
 	/* pseudo motions: keep them at the end to save space in array definition */
 	VIS_MOVE_TOTILL_REPEAT,