wip

CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.15)
 project(ke C)  # Specify C language explicitly
 
 set(CMAKE_C_STANDARD 99)
-set(KE_VERSION "1.5.1")
+set(KE_VERSION "1.5.0")
 
 set(CMAKE_C_FLAGS "-Wall -Wextra -pedantic -Wshadow -Werror -std=c99 -g")
 set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -D_DEFAULT_SOURCE -D_XOPEN_SOURCE")

Makefile

@@ -6,6 +6,7 @@ CFLAGS :=	-Wall -Wextra -pedantic -Wshadow -Werror -std=c99 -g
 CFLAGS +=	-Wno-unused-result
 CFLAGS +=	-D_DEFAULT_SOURCE -D_XOPEN_SOURCE
 CFLAGS +=	-fsanitize=address -fno-omit-frame-pointer 
+CFLAGS +=	-fprofile-instr-generate -fcoverage-mapping
 
 LDFLAGS :=	-fsanitize=address
 

default.nix

@@ -7,7 +7,7 @@
 }:
 stdenv.mkDerivation {
   pname = "ke";
-  version = "1.5.1";
+  version = "1.5.0";
 
   src = lib.cleanSource ./.;
 

main.c

@@ -95,10 +95,38 @@ struct erow {
 	int	 rsize;
 
 	int	 cap;
-	int	 dirty;
 };
 
 
+typedef enum undo_type {
+	UNDO_INSERT       = 1 << 0, /* insertch */
+	UNDO_DELETE       = 1 << 1, /* deletech */
+	UNDO_PASTE        = 1 << 2, /* yank */
+	UNDO_NEWLINE      = 1 << 3, /* newline duh */
+	UNDO_DELETE_ROW   = 1 << 4, /* delete_row duh */
+	UNDO_INDENT       = 1 << 5,
+	UNDO_UNINDENT     = 1 << 6,
+	UNDO_KILL_REGION  = 1 << 7
+} undo_flag_t;
+
+
+typedef struct undo_node {
+	undo_flag_t		 type;
+	int			 row, col;
+	struct abuf		 text;
+	struct undo_node	*next;
+	struct undo_node	*parent;
+} undo_node_t;
+
+
+typedef struct undo_tree {
+	undo_node_t	*root;
+	undo_node_t	*current;
+	undo_node_t	*saved;
+	undo_node_t	*pending;
+} undo_tree_t;
+
+
 /*
  * editor is the global editor state; it should be broken out
  * to buffers and screen state, probably.
@@ -123,6 +151,7 @@ struct editor_t {
 	int		 mark_curx, mark_cury;
 	int		 uarg, ucount; /* C-u support */
 	time_t		 msgtm;
+	undo_tree_t	*undo;
 } editor = {
 	.cols = 0,
 	.rows = 0,
@@ -144,6 +173,7 @@ struct editor_t {
 	.mark_cury = 0,
 	.uarg = 0,
 	.ucount = 0,
+	.undo = NULL,
 };
 
 
@@ -171,6 +201,60 @@ void		 erow_update(struct erow *row);
 void		 erow_insert(int at, char *s, int len);
 void		 erow_free(struct erow *row);
 
+/*
+ * undo ops
+ *
+ * notes:
+ * + undo_node_free destroys an entire timeline, including children and next.
+ * + undo_node_free_branch only discards next.
+ * + undo_discard_redo_branches kills child and next.
+ *
+ * Basic invariants of the undo system:
+ *   + root->parent == NULL
+ *   + root->current is reachable from root via repeated child walk
+ *   + saved is NULL or reachable the same way
+ *   + pending is either NULL or a brand-new node not yet linked
+ *   + when we commit, pending becomes current->child and current moves forward
+ *   + when we undo, current = current->parent
+ *   + when we type after undo, we free current->child (redo branch) first
+ *
+ * Or, visually,
+ *
+ *   root ──> N1 ──> N2 ──> N3 ──> N4* ──> N5 ──> N6   (main timeline)
+ *            ^               ^               ^
+ *            |               |               |
+ *         saved           pending        current
+ *
+ *   + root    : first edit ever, never has a parent
+ *   + current : where we are right now in history
+ *   + saved   : points to the node that matches the on-disk file
+ *   + pending : temporary node being built (committed → becomes current->child)
+ *
+ * If I do a double undo then type something:
+ *
+ *   root ──> N1 ──> N2 ──> N3* ──> N4 ──> N5   (old N4→N5→N6 discarded)
+ *                   ^           ^
+ *                   |           |
+ *                current     pending (new edit)
+ *                   |
+ *                 saved
+ *
+ * All four pointers point into the same tree → and should only be memory
+ * managed via the root node.
+ */
+undo_node_t	*undo_node_new(undo_flag_t type);
+void             undo_node_free(undo_node_t *node);
+undo_tree_t	*undo_tree_new(void);
+void             undo_tree_free(undo_tree_t *tree);
+void		 undo_begin(undo_flag_t type);
+void		 undo_append_char(char c);
+void		 undo_append(const char *data, size_t len);
+void		 undo_prepend_char(char c);
+void		 undo_prepend(const char *data, size_t len);
+void		 undo_commit(void);
+void		 undo_apply(const undo_node_t *node, int direction);
+void		 editor_undo(void);
+void		 editor_redo(void);
 
 /* kill ring, marking, etc... */
 void		 killring_flush(void);
@@ -192,14 +276,13 @@ int		 get_winsz(int *rows, int *cols);
 void		 jump_to_position(int col, int row);
 void		 goto_line(void);
 int		 cursor_at_eol(void);
-int		 iswordchar(unsigned char c);
-void		 find_next_word(void);
-void		 delete_next_word(void);
-void		 find_prev_word(void);
-void		 delete_prev_word(void);
 void		 delete_row(int at);
+void		 row_append_row(struct erow *row, char *s, int len);
 void		 row_insert_ch(struct erow *row, int at, int16_t c);
+void		 row_insert_block(struct erow *row, int at,
+			const char *data, size_t len);
 void		 row_delete_ch(struct erow *row, int at);
+void		 row_delete_block(struct erow *row, int at, size_t len);
 void		 insertch(int16_t c);
 void		 deletech(uint8_t op);
 void		 open_file(const char *filename);
@@ -367,6 +450,13 @@ init_editor(void)
 	editor.dirty = 0;
 	editor.mark_set = 0;
 	editor.mark_cury = editor.mark_curx = 0;
+
+	if (editor.undo != NULL) {
+		undo_tree_free(editor.undo);
+		editor.undo = NULL;
+	}
+
+	editor.undo = undo_tree_new();
 }
 
 
@@ -380,12 +470,17 @@ reset_editor(void)
 		erow_free(&editor.row[i]);
 	}
 	free(editor.row);
+	editor.row = NULL;
 
 	if (editor.filename != NULL) {
 		free(editor.filename);
 		editor.filename = NULL;
 	}
 
+	if (editor.undo != NULL) {
+		undo_tree_free(editor.undo);
+		editor.undo = NULL;
+	}
 
 	init_editor();
 }
@@ -601,7 +696,6 @@ erow_init(struct erow *row, int len)
 	row->render = NULL;
 	row->line = NULL;
 	row->cap = cap_growth(0, len) + 1; /* extra byte for NUL end */
-	row->dirty = 1;
 
 	row->line = malloc(row->cap);
 	assert(row->line != NULL);
@@ -698,6 +792,241 @@ erow_free(struct erow *row)
 	free(row->line);
 	row->render = NULL;
 	row->line = NULL;
+	row->cap = 0;
+	row->size = 0;
+}
+
+
+undo_node_t *
+undo_node_new(const undo_flag_t type)
+{
+	undo_node_t *node = calloc1(sizeof(undo_node_t));
+
+	node->type = type;
+	node->row = node->col = 0;
+	node->next = NULL;
+	node->parent = NULL;
+
+	ab_init(&node->text);
+
+	return node;
+}
+
+
+void
+undo_node_free(undo_node_t *node)
+{
+	if (node == NULL) {
+		return;
+	}
+
+	assert(node->next->parent == node);
+
+	ab_free(&node->text);
+	node = node->next;
+	free(node->parent);
+	node->parent = NULL;
+	free(node);
+}
+
+
+undo_tree_t *
+undo_tree_new(void)
+{
+	undo_tree_t	*tree = NULL;
+
+	tree = calloc1(sizeof(undo_tree_t));
+	tree->root = NULL;
+	tree->current = NULL;
+	tree->saved = NULL;
+	tree->pending = NULL;
+
+	return tree;
+}
+
+
+void
+undo_tree_free(undo_tree_t *tree)
+{
+	if (tree == NULL) {
+		return;
+	}
+
+	undo_node_free(tree->root);
+
+	if (tree->pending != NULL) {
+		undo_node_free(tree->pending);
+	}
+
+	if (debug_log == NULL) {
+		tree->root = NULL;
+		tree->current = NULL;
+		tree->saved = NULL;
+		tree->pending = NULL;
+	} else {
+		tree->root =
+			tree->current =
+			tree->saved =
+			tree->pending =
+			(void *)0xDEADBEEF;
+	}
+
+	free(tree);
+}
+
+
+/*
+ * undo_begin starts a new undo sequence. Note that it is a non-op
+ * if a new pending sequence doesn't need to be created.
+ */
+void
+undo_begin(undo_flag_t type)
+{
+	struct undo_tree	*tree = editor.undo;
+
+	assert(tree != NULL);
+
+	if (tree->pending != NULL) {
+		if (tree->pending->type == type) {
+			return;
+		}
+		undo_commit();
+	}
+
+	tree->pending = undo_node_new(type);
+	tree->pending->row = editor.cury;
+	tree->pending->col = editor.curx;
+}
+
+
+void
+undo_append_char(const char c)
+{
+	undo_node_t	*node = editor.undo->pending;
+
+	assert(node != NULL);
+
+	ab_appendch(&node->text, c);
+}
+
+
+void
+undo_append(const char *data, const size_t len)
+{
+	undo_node_t	*node = editor.undo->pending;
+
+	assert(node != NULL);
+
+	ab_append(&node->text, data, len);
+}
+
+
+void
+undo_prepend_char(const char c)
+{
+	undo_node_t	*node = editor.undo->pending;
+
+	assert(node != NULL);
+
+	ab_prependch(&node->text, c);
+}
+
+
+void
+undo_prepend(const char *data, const size_t len)
+{
+	undo_node_t	*node = editor.undo->pending;
+
+	assert(node != NULL);
+
+	ab_prepend(&node->text, data, len);
+}
+
+
+/*
+ * undo_commit commits the current pending tree into the root.
+ *
+ * Finish the current batch and link it into the tree.
+ * */
+void
+undo_commit(void)
+{
+	undo_tree_t	*tree = editor.undo;
+
+	assert(tree != NULL);
+
+	if (tree->pending == NULL) {
+		return; /* no pending operation */
+	}
+
+	if (tree->root == NULL) {
+
+	}
+}
+
+
+void
+undo_apply(const struct undo_node *node, const int direction)
+{
+	int	 redo;
+
+	assert(node != NULL);
+	redo = direction < 0 ? 1 : 0;
+
+	switch (node->type) {
+	default:
+		if (redo) {
+			editor_set_status("Redo isn't implemented.");
+		} else {
+			editor_set_status("Undo isn't implemented");
+		}
+	}
+}
+
+void
+undo_apply_current(int direction)
+{
+	undo_tree_t	*tree = editor.undo;
+
+	assert(tree != NULL);
+	undo_commit();
+
+	if (tree->current == NULL) {
+		editor_set_status("No further undo.");
+		return;
+	}
+
+	assert(tree->current->next == NULL);
+	undo_apply(tree->current, direction);
+
+	tree->current = tree->current->parent;
+	undo_node_free(tree->current->next);
+}
+
+
+void
+editor_undo(void)
+{
+	/*
+	 * pending should already have been committed, but it doesn't
+	 * hurt to be a little paranoid.
+	 */
+	undo_commit();
+
+	undo_apply_current(1);
+}
+
+
+void
+editor_redo(void)
+{
+	/*
+	 * pending should already have been committed, but it doesn't
+	 * hurt to be a little paranoid.
+	 */
+	undo_commit();
+
+	undo_apply_current(-1);
 }
 
 
@@ -731,6 +1060,10 @@ killring_yank(void)
 			insertch(ch);
 		}
 	}
+
+	undo_begin(UNDO_PASTE);
+	undo_append(editor.killring->line, editor.killring->size);
+	undo_commit(); /* atomic */
 }
 
 
@@ -757,7 +1090,7 @@ killring_start_with_char(unsigned char ch)
 	row->line[row->size] = ch;
 	row->size++;
 	row->line[row->size] = '\0';
-	row->dirty = 1;
+	erow_update(row);
 }
 
 
@@ -777,7 +1110,7 @@ killring_append_char(unsigned char ch)
 	row->line[row->size] = ch;
 	row->size++;
 	row->line[row->size] = '\0';
-	row->dirty = 1;
+	erow_update(row);
 }
 
 
@@ -795,7 +1128,7 @@ killring_prepend_char(unsigned char ch)
 	memmove(&row->line[1], &row->line[0], row->size + 1);
 	row->line[0] = ch;
 	row->size++;
-	row->dirty = 1;
+	erow_update(row);
 }
 
 
@@ -1003,7 +1336,7 @@ unindent_region(void)
 			if (del > 0) {
 				memmove(row->line, row->line + del, row->size - del + 1); /* +1 for NUL */
 				row->size -= del;
-				row->dirty = 1;
+				erow_update(row);
 			}
 		}
 	}
@@ -1162,13 +1495,6 @@ cursor_at_eol(void)
 }
 
 
-int
-iswordchar(unsigned char c)
-{
-	return isalnum(c) || c == '_' || strchr("/!@#$%^&*+-=~", c) != NULL;
-}
-
-
 void
 find_next_word(void)
 {
@@ -1176,7 +1502,7 @@ find_next_word(void)
 		move_cursor(ARROW_RIGHT, 1);
 	}
 
-	if (iswordchar(editor.row[editor.cury].line[editor.curx])) {
+	if (isalnum(editor.row[editor.cury].line[editor.curx])) {
 		while (!isspace(editor.row[editor.cury].line[editor.curx]) && !
 			cursor_at_eol()) {
 			move_cursor(ARROW_RIGHT, 1);
@@ -1203,7 +1529,7 @@ delete_next_word(void)
 		deletech(KILLRING_APPEND);
 	}
 
-	if (iswordchar(editor.row[editor.cury].line[editor.curx])) {
+	if (isalnum(editor.row[editor.cury].line[editor.curx])) {
 		while (!isspace(editor.row[editor.cury].line[editor.curx]) && !
 			cursor_at_eol()) {
 			move_cursor(ARROW_RIGHT, 1);
@@ -1340,7 +1666,7 @@ row_append_row(struct erow *row, char *s, int len)
 	memcpy(&row->line[row->size], s, len);
 	row->size += len;
 	row->line[row->size] = '\0';
-	row->dirty = 1;
+	erow_update(row);
 	editor.dirty++;
 }
 
@@ -1362,7 +1688,39 @@ row_insert_ch(struct erow *row, int at, int16_t c)
 	row->size++;
 	row->line[at] = c & 0xff;
 
-	row->dirty = 1;
+	erow_update(row);
+}
+
+
+void
+row_insert_block(struct erow *row, int at, const char *data, size_t len)
+{
+	if (at < 0) {
+		at = 0;
+	}
+
+	if (at > row->size) {
+		at = row->size;
+	}
+
+	if (len == 0) {
+		return;
+	}
+
+	if (row->size + (int)len + 1 > row->cap) {
+		row->cap = cap_growth(row->cap, row->size + len + 1);
+		row->line = realloc(row->line, row->cap);
+		assert(row->line != NULL);
+	}
+
+	memmove(row->line + at + len, row->line + at,
+		row->size - at + 1); /* +1 for NUL */
+	memcpy(row->line + at, data, len);
+	row->size += len;
+	row->line[row->size] = '\0';
+
+	erow_update(row);
+	editor.dirty++;
 }
 
 
@@ -1375,7 +1733,28 @@ row_delete_ch(struct erow *row, int at)
 
 	memmove(&row->line[at], &row->line[at + 1], row->size - at);
 	row->size--;
-	row->dirty = 1;
+	erow_update(row);
+	editor.dirty++;
+}
+
+
+void
+row_delete_block(struct erow *row, int at, size_t len)
+{
+	if (at < 0 || at >= row->size || len == 0) {
+		return;
+	}
+
+	if (at + (int)len > row->size) {
+		len = row->size - at;
+	}
+
+	memmove(row->line + at, row->line + at + len,
+		row->size - (at + len) + 1);
+	row->size -= len;
+	row->line[row->size] = '\0';
+
+	erow_update(row);
 	editor.dirty++;
 }
 
@@ -1383,6 +1762,8 @@ row_delete_ch(struct erow *row, int at)
 void
 insertch(int16_t c)
 {
+	undo_begin(UNDO_INSERT);
+
 	/*
 	 * insert_ch doesn't need to worry about how to update a
 	 * a row; it can just figure out where the cursor is
@@ -1399,7 +1780,12 @@ insertch(int16_t c)
 	row_insert_ch(&editor.row[editor.cury],
 	              editor.curx,
 	              (int16_t)(c & 0xff));
+	undo_append_char((char)c);
 	editor.curx++;
+
+	if (editor.undo->pending != NULL) {
+		editor.undo->pending->col = editor.curx;
+	}
 	editor.dirty++;
 }
 
@@ -1425,9 +1811,12 @@ deletech(uint8_t op)
 		dch = '\n';
 	}
 
+	undo_begin(UNDO_DELETE);
+
 	if (editor.curx > 0) {
 		row_delete_ch(row, editor.curx - 1);
 		editor.curx--;
+		undo_append_char(dch);
 	} else {
 		editor.curx = editor.row[editor.cury - 1].size;
 		row_append_row(&editor.row[editor.cury - 1],
@@ -1439,6 +1828,11 @@ deletech(uint8_t op)
 		delete_row(editor.cury);
 		editor.no_kill = prev;
 		editor.cury--;
+		undo_append_char('\n');
+	}
+
+	if (editor.undo->pending != NULL) {
+		editor.undo->pending->col = editor.curx;
 	}
 
 	if (op == KILLRING_FLUSH) {
@@ -1834,7 +2228,7 @@ editor_find_callback(char* query, int16_t c)
 		row = &editor.row[current];
 
 		/* Skip rendering search on raw bytes — use line[] but respect render offsets */
-		row->dirty = 1;
+		erow_update(row);
 
 		char* search_start = row->render;
 		if (current == start_row && direction == 1 && last_match == -1) {
@@ -1954,6 +2348,8 @@ move_cursor_once(int16_t c, int interactive)
 	struct erow	*row;
 	int		 reps = 0;
 
+	undo_commit();
+
 	row = (editor.cury >= editor.nrows) ? NULL : &editor.row[editor.cury];
 
 	switch (c) {
@@ -2073,6 +2469,8 @@ newline(void)
 {
 	struct erow *row = NULL;
 
+	undo_begin(UNDO_NEWLINE);
+
 	if (editor.cury >= editor.nrows) {
 		erow_insert(editor.cury, "", 0);
 		editor.cury++;
@@ -2089,13 +2487,16 @@ newline(void)
 		row = &editor.row[editor.cury];
 		row->size = editor.curx;
 		row->line[row->size] = '\0';
-		row->dirty = 1;
+		erow_update(row);
 		editor.cury++;
 		editor.curx = 0;
 	}
 
 	/* BREAK THE KILL CHAIN \m/ */
 	editor.kill = 0;
+
+	/* newlines aren't batched */
+	undo_commit();
 }
 
 
@@ -2157,6 +2558,8 @@ process_kcommand(int16_t c)
 	int	 jumpy = 0;
 	int	 reps  = 0;
 
+	undo_commit();
+
 	switch (c) {
 	case BACKSPACE:
 		while (editor.curx > 0) {
@@ -2316,10 +2719,12 @@ process_kcommand(int16_t c)
 	case 'u':
 		reps = uarg_get();
 
-		while (reps--);
+		while (reps--) {
-		editor_set_status("Undo not implemented.");
+			editor_undo();
+		}
 		break;
 	case 'U':
+		editor_redo();
 		break;
 	case 'y':
 		reps = uarg_get();
@@ -2350,6 +2755,8 @@ process_normal(int16_t c)
 {
 	int	reps = 0;
 
+	undo_commit();
+
 	/* C-u handling – must be the very first thing */
 	if (c == CTRL_KEY('u')) {
 		uarg_start();
@@ -2451,6 +2858,8 @@ process_escape(int16_t c)
 {
 	editor_set_status("hi");
 
+	undo_commit();
+
 	switch (c) {
 	case '>':
 		editor.cury = editor.nrows;
@@ -2715,11 +3124,7 @@ draw_rows(struct abuf *ab)
 			}
 		} else {
 			row = &editor.row[filerow];
-			if (row->dirty) {
+			erow_update(row);
-				erow_update(row);
-				row->dirty = 0;
-			}
-
 			len = row->rsize - editor.coloffs;
 			if (len < 0) {
 				len = 0;
@@ -2823,15 +3228,11 @@ draw_message_line(struct abuf *ab)
 void
 scroll(void)
 {
-	struct erow	*row = NULL;
 	editor.rx = 0;
 	if (editor.cury < editor.nrows) {
-		row = &editor.row[editor.cury];
+		editor.rx = erow_render_to_cursor(
-		if (row->dirty == 1) {
+			&editor.row[editor.cury],
-			erow_update(row);
+			editor.curx);
-		}
-
-		editor.rx = erow_render_to_cursor(row, editor.curx);
 	}
 
 	if (editor.cury < editor.rowoffs) {
@@ -2861,7 +3262,6 @@ display_refresh(void)
 	scroll();
 
 	ab_append(&ab, ESCSEQ "?25l", 6);
-	ab_append(&ab, ESCSEQ "H", 3);
 	display_clear(&ab);
 
 	draw_rows(&ab);
@@ -2875,7 +3275,7 @@ display_refresh(void)
 	         (editor.rx - editor.coloffs) + 1);
 	ab_append(&ab, buf, kstrnlen(buf, 32));
 	/* ab_append(&ab, ESCSEQ "1;2H", 7); */
-	ab_append(&ab, ESCSEQ "?25l", 6);
+	ab_append(&ab, ESCSEQ "?25h", 6);
 
 	kwrite(STDOUT_FILENO, ab.b, ab.len);
 	ab_free(&ab);
@@ -2895,15 +3295,6 @@ editor_set_status(const char *fmt, ...)
 }
 
 
-int
-kbhit(void)
-{
-	int	 bytes_waiting;
-	ioctl(STDIN_FILENO, FIONREAD, &bytes_waiting);
-	return bytes_waiting > 0;
-}
-
-
 void
 loop(void)
 {
@@ -2920,9 +3311,7 @@ loop(void)
 		 *
 		 */
 		if ((up = process_keypress()) != 0) {
-			while (kbhit()) {
+			while (process_keypress());
-				process_keypress();
-			}
 		}
 	}
 }
@@ -2962,11 +3351,7 @@ deathknell(void)
 		debug_log = NULL;
 	}
 
-	if (editor.killring != NULL) {
+	killring_flush();
-		erow_free(editor.killring);
-		free(editor.killring);
-		editor.killring = NULL;
-	}
 
 	reset_editor();
 	disable_termraw();