From mboxrd@z Thu Jan  1 00:00:00 1970
Received: from duke.felloff.net ([216.126.196.34]) by ewsd; Thu Nov 15 14:17:37 EST 2018
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Date: Thu, 15 Nov 2018 20:17:30 +0100
From: cinap_lenrek@felloff.net
To: 9front@9front.org
Subject: Re: [9front] man rc patch
In-Reply-To: BF76DDEC3ABAB8EB078F0BDE14A1B4FD@felloff.net
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X-Bullshit: SVG full-stack STM frontend 

consider this approach: we remove the Xqdol() instruction
and instead add a Xqw() instruction that pops a word list
and then pushes the quoted string. $"x is handled as
Xmark, Xmark, ...x..., Xdol, Xqw

one optimization is that we just exchange pointers when
the wordlist consists of just one item, avoiding the
string copy/free/alloc.

does this make sense?

diff -r f1e9a71d650a sys/src/cmd/rc/code.c
--- a/sys/src/cmd/rc/code.c	Wed Nov 14 09:12:34 2018 +0100
+++ b/sys/src/cmd/rc/code.c	Thu Nov 15 20:10:15 2018 +0100
@@ -96,8 +96,10 @@
 		break;
 	case '"':
 		emitf(Xmark);
+		emitf(Xmark);
 		outcode(c0, eflag);
-		emitf(Xqdol);
+		emitf(Xdol);
+		emitf(Xqw);
 		break;
 	case SUB:
 		emitf(Xmark);
diff -r f1e9a71d650a sys/src/cmd/rc/exec.c
--- a/sys/src/cmd/rc/exec.c	Wed Nov 14 09:12:34 2018 +0100
+++ b/sys/src/cmd/rc/exec.c	Thu Nov 15 20:10:15 2018 +0100
@@ -233,7 +233,7 @@
  * Xdelfn(name)				delete function definition
  * Xdeltraps(names)			delete named traps
  * Xdol(name)				get variable value
- * Xqdol(name)				concatenate variable components
+ * Xqw(words)				quote word list
  * Xdup[i j]				dup file descriptor
  * Xexit				rc exits with status
  * Xfalse{...}				execute {} if false
@@ -697,18 +697,22 @@
 }
 
 void
-Xqdol(void)
+Xqw(void)
 {
 	char *s;
 	word *a;
-	if(count(runq->argv->words)!=1){
-		Xerror1("variable name not singleton!");
+
+	a = runq->argv->words;
+	if(a && a->next == 0){
+		runq->argv->words = 0;
+		poplist();
+		a->next = runq->argv->words;
+		runq->argv->words = a;
 		return;
 	}
-	s = Str(runq->argv->words);
-	a = vlook(s)->val;
+	s = list2str(a);
 	poplist();
-	Pushword(list2str(a));
+	Pushword(s);
 }
 
 word*
diff -r f1e9a71d650a sys/src/cmd/rc/exec.h
--- a/sys/src/cmd/rc/exec.h	Wed Nov 14 09:12:34 2018 +0100
+++ b/sys/src/cmd/rc/exec.h	Thu Nov 15 20:10:15 2018 +0100
@@ -2,7 +2,7 @@
  * Definitions used in the interpreter
  */
 extern void Xappend(void), Xasync(void), Xbackq(void), Xbang(void), Xclose(void);
-extern void Xconc(void), Xcount(void), Xdelfn(void), Xdol(void), Xqdol(void), Xdup(void);
+extern void Xconc(void), Xcount(void), Xdelfn(void), Xdol(void), Xqw(void), Xdup(void);
 extern void Xexit(void), Xfalse(void), Xfn(void), Xfor(void), Xglob(void);
 extern void Xjump(void), Xmark(void), Xmatch(void), Xpipe(void), Xread(void);
 extern void Xrdwr(void);
diff -r f1e9a71d650a sys/src/cmd/rc/pfnc.c
--- a/sys/src/cmd/rc/pfnc.c	Wed Nov 14 09:12:34 2018 +0100
+++ b/sys/src/cmd/rc/pfnc.c	Thu Nov 15 20:10:15 2018 +0100
@@ -50,7 +50,7 @@
 	Xglobs, "Xglobs",
 	Xrdfn, "Xrdfn",
 	Xsimple, "Xsimple",
-	Xqdol, "Xqdol",
+	Xqw, "Xqw",
 0};
 
 void

--
cinap