engine: trim the key dispatch

mapget and maplookup were one trie probe with two predicates; mapmatch
returns the match kind and mapget is its exact case. movedelta is a
switch. searchkey's modifier test was unreachable behind transition's,
searchlang's Alt/Super test behind both callers' earlier returns, and
picksearch's range check behind numberedkouho. Korean key folding runs
once at the top of transition. commit() on an empty preedit is a no-op,
so the Ctrl branch and startsearch lose their haspre guards and repeated
commit/reset pairs. Ctrl+language inside a search now commits the shown
query as it does elsewhere instead of dropping it. Language ids are
documented as the Ctrl codes they are; Im parameters no longer shadow
the file's Im.

dat.h

@@ -7,6 +7,7 @@
 #define min(a, b) ((a) < (b) ? (a) : (b))
 #define max(a, b) ((a) > (b) ? (a) : (b))
 
+/* A language id is the control code of the Ctrl key that selects it. */
 enum
 {
 	LangEN	= 0x14,

strans.c

@@ -9,7 +9,6 @@ static int candidatechosen;
 static Drawcmd lastdraw;
 static Emit transjp(Im*, Rune);
 static void backjp(Im*);
-static int maplookup(Trie*, Str*, Str*);
 
 typedef struct Search Search;
 struct Search
@@ -31,6 +30,28 @@ Lang langs[] = {
 };
 int nlang = nelem(langs);
 
+/* Trie match kind for key; on an exact match out holds the value. */
+static int
+mapmatch(Trie *t, Str *key, Str *out)
+{
+	char *v;
+	int match, vlen;
+
+	sclear(out);
+	if(key->n == 0)
+		return TrieMiss;
+	match = trielookup(t, key, &v, &vlen);
+	if(match == TrieExact && !sinit(out, v, vlen))
+		return TrieMiss;
+	return match;
+}
+
+int
+mapget(Trie *t, Str *key, Str *out)
+{
+	return mapmatch(t, key, out) == TrieExact;
+}
+
 static void
 clearkouho(void)
 {
@@ -56,18 +77,12 @@ pagefirst(void)
 static int
 movedelta(u32int ks)
 {
-	static struct {
+	switch(ks){
-		u32int key;
+	case Kup:	return -1;
-		int delta;
+	case Kdown:	return 1;
-	} move[] = {
+	case Kpgup:	return -Maxdisp;
-		{Kup, -1}, {Kdown, 1},
+	case Kpgdown:	return Maxdisp;
-		{Kpgup, -Maxdisp}, {Kpgdown, Maxdisp},
+	}
-	};
-	int i;
-
-	for(i = 0; i < nelem(move); i++)
-		if(move[i].key == ks)
-			return move[i].delta;
 	return 0;
 }
 
@@ -271,12 +286,12 @@ commit(Str *com)
 }
 
 static void
-backjp(Im *im)
+backjp(Im *p)
 {
-	if(im->raw.n != 0)
+	if(p->raw.n != 0)
-		spopr(&im->raw);
+		spopr(&p->raw);
 	else
-		spopr(&im->pre);
+		spopr(&p->pre);
 }
 
 static int
@@ -314,7 +329,7 @@ transjp(Im *p, Rune c)
 	}
 	key = e.raw;
 	sputr(&key, c);
-	if(maplookup(p->l->map, &key, &mapped)){
+	if(mapmatch(p->l->map, &key, &mapped) != TrieMiss){
 		e.raw = key;
 		if(issmalltsu(&mapped)){
 			sappend(&e.next, &mapped);
@@ -327,7 +342,7 @@ transjp(Im *p, Rune c)
 		sclear(&e.raw);
 		sclear(&key);
 		sputr(&key, c);
-		if(maplookup(p->l->map, &key, &mapped)){
+		if(mapmatch(p->l->map, &key, &mapped) != TrieMiss){
 			e.raw = key;
 			return e;
 		}
@@ -367,43 +382,30 @@ getlang(int lang)
 	return nil;
 }
 
-static int
+/*
-maplookup(Trie *t, Str *key, Str *out)
+ * The pending text is the key sequence itself while it is a prefix of some
-{
+ * map entry; the map value is what gets shown and committed.
-	char *v;
+ */
-	int match, vlen;
-
-	sclear(out);
-	if(key->n == 0)
-		return 0;
-	match = trielookup(t, key, &v, &vlen);
-	if(match == TrieMiss)
-		return 0;
-	if(match == TrieExact && !sinit(out, v, vlen))
-		return 0;
-	return 1;
-}
-
 Emit
-transmap(Im *im, Rune c)
+transmap(Im *p, Rune c)
 {
 	Emit e = {0};
 	Str key, mapped;
 	Trie *t;
 
-	t = im->l->map;
+	t = p->l->map;
-	key = im->pre;
+	key = p->pre;
 	sputr(&key, c);
-	if(maplookup(t, &key, &mapped)){
+	if(mapmatch(t, &key, &mapped) != TrieMiss){
 		e.eat = 1;
 		e.next = key;
 		return e;
 	}
-	if(!mapget(t, &im->pre, &e.s))
+	if(!mapget(t, &p->pre, &e.s))
-		e.s = im->pre;
+		e.s = p->pre;
 	sclear(&key);
 	sputr(&key, c);
-	if(!maplookup(t, &key, &mapped))
+	if(mapmatch(t, &key, &mapped) == TrieMiss)
 		return e;
 	e.eat = 1;
 	sputr(&e.next, c);
@@ -533,13 +535,9 @@ searchquery(void)
 }
 
 static int
-searchlang(Rune c, u32int mod)
+searchlang(Rune c)
 {
-	if(mod & (Malt|Msuper))
+	return c == LangEMOJI || c == LangHANJA ? c : 0;
-		return 0;
-	if(c == LangEMOJI || c == LangHANJA)
-		return c;
-	return 0;
 }
 
 static void
@@ -551,17 +549,13 @@ endsearch(void)
 	clearkouho();
 }
 
+/* A search commits any pending composition and takes over the keys. */
 static void
 startsearch(int lang, Str *com)
 {
-	if(haspre(&im))
 	commit(com);
-	sclear(&im.pre);
+	endsearch();
-	sclear(&im.raw);
-	clearkouho();
 	search.lang = lang;
-	sclear(&search.raw);
-	sclear(&search.text);
 }
 
 static void
@@ -571,14 +565,11 @@ commitsearch(Str *com)
 	endsearch();
 }
 
-static int
+static void
 picksearch(int n, Str *com)
 {
-	if(n < 0 || n >= im.nkouho)
-		return 0;
 	sappend(com, &im.kouho[n]);
 	endsearch();
-	return 1;
 }
 
 static int
@@ -587,8 +578,6 @@ searchkey(u32int ks, u32int mod, Str *com)
 	int n;
 	Rune c;
 
-	if(ismodkey(ks))
-		return 0;
 	n = movedelta(ks);
 	if(n != 0){
 		if(im.nkouho == 0)
@@ -617,7 +606,8 @@ searchkey(u32int ks, u32int mod, Str *com)
 	}
 	if(ks == Kret){
 		if(im.nkouho > 0)
-			return picksearch(im.sel >= 0 ? im.sel : 0, com);
+			picksearch(max(im.sel, 0), com);
+		else
 			commitsearch(com);
 		return 1;
 	}
@@ -641,25 +631,21 @@ searchkey(u32int ks, u32int mod, Str *com)
 	}
 	if(mod & Mctrl){
 		c = ctrlkey(ks);
-		n = searchlang(c, mod);
+		n = searchlang(c);
-		if(n != 0){
 		if(n == search.lang)
 			endsearch();
-			else
+		else if(n != 0)
 			startsearch(n, com);
-			return 1;
+		else{
+			commitsearch(com);
+			return setlang(c);
 		}
-		endsearch();
-		if(setlang(c))
 		return 1;
-		return 0;
 	}
 	if(search.raw.n >= Maxrunes){
 		commitsearch(com);
 		return 0;
 	}
-	if(im.l->lang == LangKO)
-		ks = kokey(ks, mod);
 	sputr(&search.raw, ks);
 	searchquery();
 	return 1;
@@ -673,6 +659,8 @@ transition(u32int ks, u32int mod, Str *com)
 
 	if(ismodkey(ks))
 		return 0;
+	if(im.l->lang == LangKO)
+		ks = kokey(ks, mod);
 	if(search.lang)
 		return searchkey(ks, mod, com);
 	n = movedelta(ks);
@@ -728,22 +716,14 @@ transition(u32int ks, u32int mod, Str *com)
 	}
 	if(mod & Mctrl){
 		c = ctrlkey(ks);
-		n = searchlang(c, mod);
+		n = searchlang(c);
 		if(n != 0){
 			startsearch(n, com);
 			return 1;
 		}
-		if(getlang(c) != nil){
-			if(haspre(&im))
 		commit(com);
 		reset();
-			setlang(c);
+		return setlang(c);
-			return 1;
-		}
-		if(haspre(&im))
-			commit(com);
-		reset();
-		return 0;
 	}
 	if(ks == '0' && im.nkouho > 0){
 		commit(com);
@@ -768,10 +748,7 @@ transition(u32int ks, u32int mod, Str *com)
 		reset();
 		return 0;
 	}
-	if(im.l->lang == LangKO)
+	return dotrans(ks, com);
-		ks = kokey(ks, mod);
-	n = dotrans(ks, com);
-	return n;
 }
 
 static void
@@ -871,14 +848,3 @@ imthread(void*)
 	}
 }
 
-int
-mapget(Trie *t, Str *key, Str *out)
-{
-	char *v;
-	int vlen;
-
-	sclear(out);
-	if(key->n == 0 || trielookup(t, key, &v, &vlen) != TrieExact)
-		return 0;
-	return sinit(out, v, vlen);
-}

tests/engine_test.c

@@ -1570,6 +1570,17 @@ engine_emoji_start_and_unknown(struct ct *t)
 		CT_EQ_INT(t, LangKO, im.l->lang);
 	}
 
+	/* A language switch commits the query like any other pending text. */
+	sclear(&com);
+	CT_CHECK(t, keystroke('e', Mctrl, &com));
+	if(typekeys(t, "xy", &com)){
+		CT_CHECK(t, keystroke('t', Mctrl, &com));
+		checkstr(t, "language switch commits query", "xy", &com);
+		CT_CHECK(t, !search.lang);
+		CT_EQ_INT(t, LangEN, im.l->lang);
+		im.l = getlang(LangKO);
+	}
+
 	sclear(&com);
 	CT_CHECK(t, keystroke('e', Mctrl, &com));
 	for(i = 0; i < Maxrunes; i++)