acme: Reverse search

src/cmd/acme/exec.c

@@ -83,6 +83,7 @@ static Rune LKill[] = { 'K', 'i', 'l', 'l', 0 };
 static Rune LLoad[] = { 'L', 'o', 'a', 'd', 0 };
 static Rune LLocal[] = { 'L', 'o', 'c', 'a', 'l', 0 };
 static Rune LLook[] = { 'L', 'o', 'o', 'k', 0 };
+static Rune LKool[] = { 'K', 'o', 'o', 'l', 0 };
 static Rune LNew[] = { 'N', 'e', 'w', 0 };
 static Rune LNewcol[] = { 'N', 'e', 'w', 'c', 'o', 'l', 0 };
 static Rune LPaste[] = { 'P', 'a', 's', 't', 'e', 0 };
@@ -113,7 +114,8 @@ Exectab exectab[] = {
 	{ LKill,		xkill,		FALSE,	XXX,		XXX		},
 	{ LLoad,		dump,	FALSE,	FALSE,	XXX		},
 	{ LLocal,		local,	FALSE,	XXX,		XXX		},
-	{ LLook,		look,		FALSE,	XXX,		XXX		},
+	{ LLook,		look,		FALSE,	FALSE,	XXX		},
+	{ LKool,		look,		FALSE,	TRUE,	XXX		},
 	{ LNew,		new,		FALSE,	XXX,		XXX		},
 	{ LNewcol,	newcol,	FALSE,	XXX,		XXX		},
 	{ LPaste,		paste,	TRUE,	TRUE,	XXX		},
@@ -1072,18 +1074,17 @@ paste(Text *et, Text *t, Text *_0, int selectall, int tobody, Rune *_1, int _2)
 }
 
 void
-look(Text *et, Text *t, Text *argt, int _0, int _1, Rune *arg, int narg)
+look(Text *et, Text *t, Text *argt, int rev, int _1, Rune *arg, int narg)
 {
 	Rune *r;
 	int n;
 
-	USED(_0);
 	USED(_1);
 
 	if(et && et->w){
 		t = &et->w->body;
 		if(narg > 0){
-			search(t, arg, narg);
+			rev ? rsearch(t, arg, narg) : search(t, arg, narg);
 			return;
 		}
 		getarg(argt, FALSE, FALSE, &r, &n);
@@ -1092,7 +1093,7 @@ look(Text *et, Text *t, Text *argt, int _0, int _1, Rune *arg, int narg)
 			r = runemalloc(n);
 			bufread(&t->file->b, t->q0, r, n);
 		}
-		search(t, r, n);
+		rev ? rsearch(t, r, n) : search(t, r, n);
 		free(r);
 	}
 }

src/cmd/acme/fns.h

@@ -64,6 +64,7 @@ void	fontx(Text*, Text*, Text*, int, int, Rune*, int);
 int	isalnum(Rune);
 void	execute(Text*, uint, uint, int, Text*);
 int	search(Text*, Rune*, uint);
+int	rsearch(Text*, Rune*, uint);
 void	look3(Text*, uint, uint, int);
 void	editcmd(Text*, Rune*, uint);
 uint	min(uint, uint);

src/cmd/acme/look.c

@@ -302,20 +302,76 @@ plumbshow(Plumbmsg *m)
 	xfidlog(w, "new");
 }
 
+int
+rsearch(Text *ct, Rune *r, uint n)
+{
+	int q, nb;
+	int around;
+	Rune *s, *b;
+
+	if(n==0 || n>ct->file->b.nc)
+		return FALSE;
+	if(2*n > RBUFSIZE){
+		warning(nil, "string too long\n");
+		return FALSE;
+	}
+	s = fbufalloc();
+	b = s;
+	nb = 0;
+	b[nb] = 0;
+	around = 0;
+	q = ct->q0;
+	for(;;){
+		if(q < 0){
+			q = ct->file->b.nc;
+			around = 1;
+			b = s;
+			nb = 0;
+			b[nb] = 0;
+		}
+		/* reload if buffer covers neither string nor rest of file */
+		if(nb<n && nb!=q){
+			nb = min(q, RBUFSIZE-1);
+			bufread(&ct->file->b, q-nb, s, nb);
+			b = s+nb;
+			*b = 0;
+		}
+		/* this runeeq is fishy but the null at b[nb] makes it safe */
+		if(runeeq(b, n, r, n)==TRUE){
+			if(ct->w){
+				textshow(ct, q, q+n, 1);
+				winsettag(ct->w);
+			}else{
+				ct->q0 = q;
+				ct->q1 = q+n;
+			}
+			seltext = ct;
+			fbuffree(s);
+			return TRUE;
+		}
+		--nb;
+		--b;
+		--q;
+		if(around && q<=ct->q0)
+			break;
+	}
+	fbuffree(s);
+	return FALSE;
+}
+
 int
 search(Text *ct, Rune *r, uint n)
 {
-	uint q, nb, maxn;
+	uint q, nb;
 	int around;
-	Rune *s, *b, *c;
+	Rune *s, *b;
 
 	if(n==0 || n>ct->file->b.nc)
 		return FALSE;
 	if(2*n > RBUFSIZE){
 		warning(nil, "string too long\n");
 		return FALSE;
 	}
-	maxn = max(2*n, RBUFSIZE);
 	s = fbufalloc();
 	b = s;
 	nb = 0;
@@ -329,25 +385,9 @@ search(Text *ct, Rune *r, uint n)
 			nb = 0;
 			b[nb] = 0;
 		}
-		if(nb > 0){
-			c = runestrchr(b, r[0]);
-			if(c == nil){
-				q += nb;
-				nb = 0;
-				b[nb] = 0;
-				if(around && q>=ct->q1)
-					break;
-				continue;
-			}
-			q += (c-b);
-			nb -= (c-b);
-			b = c;
-		}
 		/* reload if buffer covers neither string nor rest of file */
 		if(nb<n && nb!=ct->file->b.nc-q){
-			nb = ct->file->b.nc-q;
-			if(nb >= maxn)
-				nb = maxn-1;
+			nb = min(ct->file->b.nc-q, RBUFSIZE-1);
 			bufread(&ct->file->b, q, s, nb);
 			b = s;
 			b[nb] = '\0';