1 files changed, 91 insertions, 0 deletions
diff --git a/appl/alphabet/grid/line2rec.b b/appl/alphabet/grid/line2rec.b
new file mode 100644
index 00000000..2429a67d
--- /dev/null
+++ b/appl/alphabet/grid/line2rec.b
@@ -0,0 +1,91 @@
+implement Line2rec, Gridmodule;
+include "sys.m";
+	sys: Sys;
+include "draw.m";
+include "sh.m";
+include "bufio.m";
+	bufio: Bufio;
+	Iobuf: import bufio;
+include "alphabet/reports.m";
+	reports: Reports;
+		Report, report: import reports;
+include "alphabet/endpoints.m";
+include "alphabet/grid.m";
+	grid: Grid;
+	Value: import grid;
+
+Line2rec: module {};
+
+types(): string
+{
+	return "bf";
+}
+
+init()
+{
+	sys = load Sys Sys->PATH;
+	grid = load Grid Grid->PATH;
+	reports = load Reports Reports->PATH;
+	bufio = load Bufio Bufio->PATH;
+}
+
+quit()
+{
+}
+
+run(nil: chan of string, r: ref Report,
+		nil: list of (int, list of ref Value), args: list of ref Value): ref Value
+{
+	f := chan of ref Sys->FD;
+	spawn line2recproc((hd args).f().i, f, r.start("line2rec"));
+	return ref Value.Vb(f);
+}
+
+line2recproc(
+	f0,
+	f1: chan of ref Sys->FD,
+	errorc: chan of string)
+{
+	(fd0, fd1) := startfilter(f0, f1, errorc);
+	iob0 := bufio->fopen(fd0, Sys->OREAD);
+	iob1 := bufio->fopen(fd1, Sys->OWRITE);
+	{
+		while((s := iob0.gets('\n')) != nil){
+			d := array of byte s;
+			if(iob1.puts("data "+string len d) < 0)
+				break;
+			if(iob1.write(d, len d) != len d)
+				break;
+		}
+		iob1.flush();
+		sys->fprint(fd1, "");
+	}exception{
+	"write on closed pipe" =>
+		;
+	}
+	reports->quit(errorc);
+}
+
+# read side (when it's an argument):
+# 	read proposed new fd
+# 	write actual fd for them to write to (creating pipe in necessary)
+# 
+# write side (when you're returning it):
+# 	write a proposed new fd (or nil if no suggestion)
+# 	read actual fd for writing
+startfilter(f0, f1: chan of ref Sys->FD, errorc: chan of string): (ref Sys->FD, ref Sys->FD)
+{
+	f1 <-= nil;
+	if((fd1 := <-f1) == nil){
+		<-f0;
+		f0 <-= nil;
+		reports->quit(errorc);
+	}
+	if((fd0 := <-f0) == nil){
+		sys->pipe(p := array[2] of ref Sys->FD);
+		f0 <-= p[1];
+		fd0 = p[0];
+	}else
+		f0 <-= nil;
+	return (fd0, fd1);
+}