From 411a46eff224c2cade990436d52956aa50dbd77b Mon Sep 17 00:00:00 2001
From: Curtis McEnroe <june@causal.agency>
Date: Sun, 11 Aug 2019 01:40:12 -0400
Subject: Use low numbers for states

---
 term.c | 110 +++++++++++++++++++++++++++++++++--------------------------------
 term.h |   2 +-
 2 files changed, 57 insertions(+), 55 deletions(-)

diff --git a/term.c b/term.c
index 8c2ee9f..7bc6282 100644
--- a/term.c
+++ b/term.c
@@ -36,10 +36,10 @@ static void unhandled(const char *format, ...) {
 	va_end(ap);
 }
 
-static struct Cell *cell(struct Term *t, uint y, uint x) {
-	assert(y < t->rows);
-	assert(x < t->cols);
-	return &t->cells[y * t->cols + x];
+static struct Cell *cell(struct Term *term, uint y, uint x) {
+	assert(y < term->rows);
+	assert(x < term->cols);
+	return &term->cells[y * term->cols + x];
 }
 
 static void erase(struct Style style, struct Cell *a, struct Cell *b) {
@@ -53,49 +53,51 @@ static void move(struct Cell *dst, struct Cell *src, uint len) {
 	memmove(dst, src, sizeof(*dst) * len);
 }
 
-static void scrollUp(struct Term *t, uint top, uint n) {
+static void scrollUp(struct Term *term, uint top, uint n) {
 	move(
-		cell(t, top, 0),
-		cell(t, top + n, 0),
-		t->cols * (1 + t->scroll.bot - top - n)
+		cell(term, top, 0),
+		cell(term, top + n, 0),
+		term->cols * (1 + term->scroll.bot - top - n)
 	);
 	erase(
-		t->style,
-		cell(t, 1 + t->scroll.bot - n, 0),
-		cell(t, t->scroll.bot, t->cols - 1)
+		term->style,
+		cell(term, 1 + term->scroll.bot - n, 0),
+		cell(term, term->scroll.bot, term->cols - 1)
 	);
 }
 
-static void scrollDown(struct Term *t, uint top, uint n) {
+static void scrollDown(struct Term *term, uint top, uint n) {
 	move(
-		cell(t, top + n, 0),
-		cell(t, top, 0),
-		t->cols * (1 + t->scroll.bot - top - n)
+		cell(term, top + n, 0),
+		cell(term, top, 0),
+		term->cols * (1 + term->scroll.bot - top - n)
 	);
 	erase(
-		t->style,
-		cell(t, top, 0),
-		cell(t, top + n - 1, t->cols - 1)
+		term->style,
+		cell(term, top, 0),
+		cell(term, top + n - 1, term->cols - 1)
 	);
 }
 
-typedef void Action(struct Term *, wchar_t ch);
+typedef void Action(struct Term *, wchar_t);
 
 #define ACTION(name) \
-	static void name(struct Term *t, wchar_t _ch __attribute__((__unused__)))
+	static void name(struct Term *t, wchar_t _ch __attribute__((unused)))
 
 enum {
-	G0  = '(',
-	CSI = '[',
-	ST = '\\',
-	OSC = ']',
+	Def,
+	Esc,
+	G0,
+	CSI,
+	OSC,
+	OSCEsc,
 };
 
-ACTION(nop) { (void)t; }
-ACTION(esc) { t->state = ESC; }
-ACTION(g0)  { t->state = G0; }
-ACTION(osc) { t->state = OSC; }
-ACTION(st)  { t->state = ST; }
+ACTION(nop)    { (void)t; }
+ACTION(esc)    { t->state = Esc; }
+ACTION(g0)     { t->state = G0; }
+ACTION(osc)    { t->state = OSC; }
+ACTION(oscEsc) { t->state = OSCEsc; }
 ACTION(csi) {
 	t->state = CSI;
 	memset(&t->param, 0, sizeof(t->param));
@@ -357,23 +359,23 @@ static void add(struct Term *t, wchar_t ch) {
 }
 
 static Action *Actions[][128] = {
-	[NUL][0]   = add,
-	[NUL][BEL] = nop,
-	[NUL][BS]  = bs,
-	[NUL][HT]  = ht,
-	[NUL][NL]  = nl,
-	[NUL][CR]  = cr,
-	[NUL][ESC] = esc,
-
-	[ESC][0]   = escUnhandled,
-	[ESC]['('] = g0,
-	[ESC]['7'] = decsc,
-	[ESC]['8'] = decrc,
-	[ESC]['='] = nop,
-	[ESC]['>'] = nop,
-	[ESC]['M'] = ri,
-	[ESC]['['] = csi,
-	[ESC][']'] = osc,
+	[Def][0]   = add,
+	[Def][BEL] = nop,
+	[Def][BS]  = bs,
+	[Def][HT]  = ht,
+	[Def][NL]  = nl,
+	[Def][CR]  = cr,
+	[Def][ESC] = esc,
+
+	[Esc][0]   = escUnhandled,
+	[Esc]['('] = g0,
+	[Esc]['7'] = decsc,
+	[Esc]['8'] = decrc,
+	[Esc]['='] = nop,
+	[Esc]['>'] = nop,
+	[Esc]['M'] = ri,
+	[Esc]['['] = csi,
+	[Esc][']'] = osc,
 	
 	[G0][0]    = nop,
 
@@ -404,18 +406,19 @@ static Action *Actions[][128] = {
 	
 	[OSC][0]   = osc,
 	[OSC][BEL] = nop,
-	[OSC][ESC] = st,
-	[ST][0]    = osc,
-	[ST]['\\'] = nop,
+	[OSC][ESC] = oscEsc,
+
+	[OSCEsc][0] = osc,
+	[OSCEsc]['\\'] = nop,
 };
 
 void termUpdate(struct Term *term, wchar_t ch) {
-	assert((uint)term->state < sizeof(Actions) / sizeof(Actions[0]));
+	assert(term->state < sizeof(Actions) / sizeof(Actions[0]));
 	Action *action = NULL;
-	if (ch < 128) action = Actions[(uint)term->state][ch];
-	if (!action) action = Actions[(uint)term->state][0];
+	if (ch < 128) action = Actions[term->state][ch];
+	if (!action) action = Actions[term->state][0];
 	assert(action);
-	term->state = NUL;
+	term->state = Def;
 	action(term, ch);
 }
 
@@ -428,7 +431,6 @@ struct Term *termAlloc(uint rows, uint cols) {
 	term->rows = rows;
 	term->cols = cols;
 	term->mode = Wrap | Cursor;
-	term->scroll.top = 0;
 	term->scroll.bot = rows - 1;
 	term->style = Default;
 	erase(Default, cell(term, 0, 0), cell(term, rows - 1, cols - 1));
diff --git a/term.h b/term.h
index 03d9ac5..2bc4dcb 100644
--- a/term.h
+++ b/term.h
@@ -58,7 +58,7 @@ enum { ParamCap = 16 };
 
 struct Term {
 	uint rows, cols;
-	char state;
+	uint state;
 	struct {
 		bool q;
 		uint s[ParamCap];
-- 
cgit 1.4.1