fix: data() x=middle, offset calc for wrapped lines with tabs

README.md

@@ -1,6 +1,6 @@
 # Yocto
 [![C/C++ CI](https://github.com/ikozyris/yocto/actions/workflows/c-cpp.yml/badge.svg)](https://github.com/ikozyris/yocto/actions/workflows/c-cpp.yml)
-A simple, compact and *fast* text editor using ncurses and a gap buffer, written in C++, in <1k lines of code.
+A simple, compact and *fast* text editor using ncurses and a gap buffer, written in C++, in ~1k lines of code.
 More information is available on the [wiki](https://github.com/ikozyris/yocto/wiki).
 
 ![A C++ file in Yocto](https://github.com/ikozyris/yocto/assets/80053394/8fa12952-272f-41e0-9535-0a77f3652286)
@@ -11,12 +11,12 @@ make build
 sudo make install
 ```
 
-Or use the user-friendly dialog utility (`wizard.sh`)
+Or use the user-friendly dialog utility `wizard.sh`
 which also supports configuring yocto
 
 ### Keybindings
 * Save: Ctrl-S
-* Exit: Ctrl-C
+* Exit: Ctrl-X
 * Go to start of line: Ctrl-A
 * Go to end of line: Ctrl-E
 * Open other file Alt-R
@@ -25,7 +25,7 @@ which also supports configuring yocto
 * Show info: Alt-I (also command _stats_ in built-in terminal)
 
 ### How fast is it?
-Yocto is more than 3x faster than emacs, 4x vim and 6x nano at reading a file.
+Yocto is several times faster than any other text editor at reading files and other operations.
 See the [benchmarks](https://github.com/ikozyris/yocto/wiki/Performance-&-Benchmarks) for more.
 
 ### About the name

headers/gapbuffer.hpp

@@ -17,9 +17,9 @@ unsigned lnbf_cpt; // linebuff capacity
 #define max(a, b) ((a) > (b) ? (a) : (b))
 
 struct gap_buf {
-	unsigned cpt; 	// allocated size (1)
+	unsigned cpt; 	// allocated size (1-based)
 	unsigned len;	// length of line (1)
-	unsigned gps;	// gap start (first element of gap) (0)
+	unsigned gps;	// gap start (first element of gap) (0-based)
 	unsigned gpe;	// gap end (last element of gap)    (0)
 	char *buffer;
 
@@ -146,40 +146,32 @@ inline void eras(gap_buf &a)
 // NOTE: destination buffer is lnbuf
 unsigned data(const gap_buf &src, unsigned from, unsigned to)
 {
-	if (src.len == 0) {
-		lnbuf[0] = 0;
-		return 0;
-	}
+	if (src.len == 0)
+		return lnbuf[0] = 0;
 	if (lnbf_cpt < to - from + 3) {
 		free(lnbuf);
 		lnbf_cpt = to - from + 10;
 		lnbuf = (char*)malloc(lnbf_cpt);
 	}
-	lnbuf[to - from] = 0;
-	lnbuf[to - from + 1] = 0;
+	lnbuf[to - from + 1] = lnbuf[to - from] = 0;
 	// try some special cases where 1 copy is required
 	if (src.gps == src.len && src.gpe == src.cpt - 1) // gap ends at end
 		memcpy(lnbuf, src.buffer + from, min(to, src.gps));
 	else if (src.gps == 0) // x = 0; gap at start
 		memcpy(lnbuf, src.buffer + from + src.gpe + 1, min(to, src.len) - from);
 	else {
-		if (from < src.gps) { // worst case
-			for (unsigned i = from; i < src.gps; ++i)
-				lnbuf[i] = src[i];
-			for (unsigned i = src.gpe + 1; i < gaplen(src) + to; ++i)
-				lnbuf[i - gaplen(src)] = src[i];
-			//memcpy(tmp, src.buffer + from, min(to, src.gps));
-			//memcpy(tmp + min(to, src.gps), src.buffer +, src.gps - to - 1);
+		if (from < src.gps) {
+			memcpy(lnbuf, src.buffer + from, min(to, src.gps) - from);
+			if (to > src.gps - 1)
+				memcpy(lnbuf + src.gps, src.buffer + src.gpe + 1, to - from - src.gps);
 		} else
-			for (unsigned i = gaplen(src) + src.gps; i < gaplen(src) + to; ++i)
-				lnbuf[i - gaplen(src) - 1] = src[i];
-			//memcpy(tmp, src.buffer + src.gpe + 1, src.gps - to);
+			memcpy(lnbuf, src.buffer + from + gaplen(src), (to - from) + gaplen(src));
 	}
 	lnbuf[to - from + 2] = 0;
 	return to - from;
 }
 
-// naive, simplier, slower, should be bug free, implementation of above function 
+// naive, simplier, slower, implementation of above function 
 unsigned data2(const gap_buf &src, const unsigned from, const unsigned to) {
 	char *buffer = (char*)malloc(src.len + 3);
 	memcpy(buffer, src.buffer, src.gps);
@@ -194,8 +186,7 @@ unsigned data2(const gap_buf &src, const unsigned from, const unsigned to) {
 	}
 	memcpy(lnbuf, buffer + from, to - from);
 	free(buffer);
-	lnbuf[to - from + 1] = 0;
-	lnbuf[to - from + 2] = 0;
+	lnbuf[to - from + 1] = lnbuf[to - from + 2] = 0;
 	return to - from;
 }
 

headers/keybindings.h

@@ -6,7 +6,7 @@
 
 #define ENTER		KEY_ENTER
 #define SAVE		ctrl('S')
-#define EXIT		ctrl('C')
+#define EXIT		ctrl('X')
 #define UP		KEY_UP
 #define DOWN		KEY_DOWN
 #define LEFT		KEY_LEFT

headers/vars.hpp

@@ -14,8 +14,8 @@ WINDOW *header_win, *ln_win, *text_win;
 wchar_t s[6];
 char s2[6];
 unsigned char y, x, len;
-// offset in y axis of text and screen, x axis equivalents are in gapbuffer
-long ofy;
+long ofy; // offset in y axis of text and screen, x axis is in gapbuffer
+long ofx2; // this is last change in ofx
 unsigned ry, rx;
 unsigned buf_indx, printed, previndx, ppi;
 unsigned maxy, maxx; // to store the maximum rows and columns

main.cpp

@@ -76,7 +76,6 @@ int main(int argc, char *argv[])
 
 	it = text.begin();
 loop:
-	//goto stop;
 	while (1) {
 		getyx(text_win, y, x);
 		ry = y + ofy;
@@ -89,12 +88,10 @@ int main(int argc, char *argv[])
 
 #ifdef DEBUG
 		print_text(y); // debug only
-		char tmp[80];
-		snprintf(tmp, 79, "st %u | end %u | cpt %u | len %u | maxx %u | ofx %ld    ",
-			it->gps, it->gpe, it->cpt, it->len, maxx, ofx);
-		print2header(tmp, 1);
+		stats();
 		wmove(text_win, y, x);
 #endif
+	//goto stop;
 		wget_wch(text_win, (wint_t*)s);
 		switch (s[0]) {
 		case DOWN:
@@ -119,36 +116,18 @@ int main(int argc, char *argv[])
 			break;
 
 		case LEFT:
-			if (x == 0 && ofx > 0) { // line has been wrapped
-				wmove(text_win, y, 0);
-				wclrtoeol(text_win);
-				print_line(*it);
-#ifdef HIGHLIGHT
-				wmove(text_win, y, 0);
-				apply(y);
-#endif
-				ofx -= maxx - 1;
-				wmove(text_win, y, maxx - 1);
-			} else if (x > 0) {
-				if (it->buffer[it->gps - 1] == '\t') {
-					wmove(text_win, y, x - 8);
-					ofx += 7;
-					break;
-				}
-				wmove(text_win, y, x - 1);
-				if (it->buffer[it->gps - 1] < 0)
-					--ofx;
-			} else if (y > 0) { // x = 0
-				if (ofx > 0) // revert wrap
-					print_line(*it);
-				--it;
-				--y;
-				eol();
-			}
+			if (x == 0 && ofx == 0 && ofy > 0 && y == 0)
+				scrollup();
+			else
+				left();
 			break;
 
 		case RIGHT:
-			right();
+			if (y == maxy - 1 && rx == it->len - 1) {
+				++it;
+				scrolldown();
+			} else
+				right();
 			break;
 
 		case BACKSPACE:

utils/io.cpp

@@ -35,15 +35,16 @@ char *input_header(const char *q)
 	return tmp;
 }
 
-unsigned print_line(const gap_buf &buffer, unsigned from = 0, unsigned to = -1)
+unsigned print_line(const gap_buf &buffer, unsigned from = 0, unsigned to = 0xffffffff)
 {
-	if (to == -1)
-		to = buffer.len;
 	if (buffer.len == 0)
 		return 0;
-	unsigned rlen = data2(buffer, from, min(to, maxx * 2));
+	if (to == 0xffffffff) // 2^32-1
+		to = buffer.len;
+	unsigned rlen = data(buffer, from, min(to, maxx * 2));
 	if (lnbuf[rlen - 1] == '\n')
 		--rlen;
+	// TODO: is there a faster way?
 	waddnstr(text_win, lnbuf, min(maxy / 2, rlen));
 	// make sure we don't print more than needed (utf8, tabs...)
 	for (unsigned i = maxy / 2; i < rlen && (unsigned)getcurx(text_win) < maxx - 1; ++i)

utils/key_func.cpp

@@ -6,6 +6,8 @@ void stats()
 	unsigned sumlen = 0;
 	for (auto &i : text)
 		sumlen += i.len;
+	//snprintf(_tmp, maxx, "st %u | end %u | cpt %u | len %u | maxx %u | ofx %ld    ",
+	//	it->gps, it->gpe, it->cpt, it->len, maxx, ofx);
 	snprintf(_tmp, maxx, "length %u y %u x %u sum len %u lines %lu ofx %ld  ", 
 		it->len, ry, x, sumlen, curnum, ofx);
 	print2header(_tmp, 1);
@@ -121,8 +123,8 @@ void enter()
 
 	gap_buf *t = (gap_buf*)malloc(sizeof(gap_buf));
 	init(*t);
-	if (it->gpe < it->cpt - 1) { // newline is not at the end
-		data2(*it, rx + 1, it->len + 1);
+	if (it->gpe < it->cpt - 2) { // newline is not at the end
+		data(*it, rx + 1, it->len + 1);
 		apnd_s(*t, lnbuf, it->len - rx - 1);
 		it->gps = rx + 1;
 		it->len = rx + 1;
@@ -157,25 +159,24 @@ void eol()
 	} else { // wrap line
 		wmove(text_win, y, 0);
 		wclrtoeol(text_win);
-		// TODO: use actual printline()
 		print_line(*it, it->len - maxx - ofx, it->len);
-		ofx = (long)it->len - (long)maxx - ofx;
+		ofx = (ofx2 = (long)it->len - (long)maxx - ofx);
 	}
 }
 
 void sol()
 {
 	wmove(text_win, y, 0);
 	if (ofx < 0)
-		ofx = 0;
+		ofx2 = ofx = 0;
 	else if (ofx >= (long)it->len - maxx) { // line has been wrapped
 		wclrtoeol(text_win);
-		print_line(*it);
+		print_line(*it, 0, maxx);
 #ifdef HIGHLIGHT
 		wmove(text_win, y, 0);
 		apply(y);
 #endif
-		ofx = 0;
+		ofx2 = ofx = 0;
 		wmove(text_win, y, 0);
 	}
 }
@@ -216,6 +217,38 @@ void scrollup()
 }
 
 // TODO: is all this complexity needed?
+void left()
+{
+	if (x == 0 && ofx > 0) { // line has been wrapped
+		wmove(text_win, y, 0);
+		wclrtoeol(text_win);
+		print_line(*it);
+#ifdef HIGHLIGHT
+		wmove(text_win, y, 0);
+		apply(y);
+#endif
+		ofx -= ofx2;
+		ofx2 = 0;
+		wmove(text_win, y, maxx - 1);
+	} else if (x > 0) {
+		// TODO: use nextword() to get actual offset
+		if (it->buffer[it->gps - 1] == '\t') {
+			wmove(text_win, y, x - 8);
+			ofx += 7;
+			return;
+		}
+		wmove(text_win, y, x - 1);
+		if (it->buffer[it->gps - 1] < 0)
+			--ofx;
+	} else if (y > 0) { // x = 0
+		if (ofx > 0) // revert wrap
+			print_line(*it);
+		--it;
+		--y;
+		eol();
+	}
+}
+
 void right()
 {
 	if (it->buffer[it->gpe + 1] == '\t') {
@@ -229,9 +262,9 @@ void right()
 		wclrtoeol(text_win);
 		// TODO: use print_line()
 		//print_line(*it, ofx + maxx - 1, it->len - maxx - ofx);
-		data2(*it, ofx + maxx - 1, ofx + maxx * 2);
+		data(*it, ofx + maxx - 1, ofx + maxx * 2);
 		waddnstr(text_win, lnbuf, it->len - maxx - ofx);
-		ofx += maxx - 1;
+		ofx2 = (ofx += maxx - 1);
 		wmove(text_win, y, 0);
 	} else {
 		if (ry < curnum) {

utils/sizes.c

@@ -7,10 +7,10 @@ const char *itoa(long a)
 	return b;
 }
 
-// convert bytes to base-10 human-readable string e.g 1024 = 1.024KB = 1KiB
+// convert bytes to base-10 (SI) human-readable string e.g 1000B = 1kB
 const char *hrsize(size_t bytes)
 {
-	const char *suffix[] = {"B", "KB", "MB", "GB", "TB"};
+	const char *suffix[] = {"B", "kB", "MB", "GB", "TB"};
 	unsigned char length = sizeof(suffix) / sizeof(suffix[0]);
 
 	double dblBytes = bytes;
@@ -26,10 +26,10 @@ const char *hrsize(size_t bytes)
 
 // get length of line y
 unsigned sizeofline(unsigned y) {
-	unsigned i = maxx - 1;
+	short i = maxx - 1;
 	wmove(text_win, y, i);
 	while ((winch(text_win) & A_CHARTEXT) == ' '
-		&& getcurx(text_win) >= it->len - 1)
+		&& (unsigned)getcurx(text_win) >= it->len - 1 && i >= 0)
 		wmove(text_win, y, --i);
 	wmove(text_win, y, i + 1);
 	return i + 2;

wizard.sh

@@ -32,7 +32,7 @@ display_result() {
 }
 
 KEY_SAVE="ctrl('S')"
-KEY_EXIT="ctrl('C')"
+KEY_EXIT="ctrl('X')"
 KEY_INFO="'i'"
 KEY_REFRESH="ctrl('R')"
 KEY_HOME="ctrl('A')"