allow setting the "*" register as an alternative to nEB

this is more consistent with SciTECO's idea of abstract registers
and allows the currend buffer to be saved on the Q-Register stack.
This allows the idiom: [* ! ...change current buffer... ! ]*

6 files changed, 45 insertions, 19 deletions

diff --git a/doc/sciteco.7.template b/doc/sciteco.7.template
index 4dd08b2..7a2e924 100644
--- a/doc/sciteco.7.template
+++ b/doc/sciteco.7.template
@@ -742,7 +742,24 @@ Replacement string register.
 Its integer part is unused.
 .TP
 .BR * " (asterisk)"
-Name and id of current buffer in ring.
+File name (string part) and id (numeric part) of current
+buffer in ring.
+The unnamed buffer has an empty name.
+If the current document is a register, this returns the
+name or id of the buffer last edited.
+The \(lq*\(rq register may also be edited but changing its
+string contents has no effect on the file name of the buffer.
+Setting the numeric part of the \(lq*\(rq register,
+as in \(lq1U*\(rq, is equivalent to editing a buffer by id
+(e.g. \(lq1EB\fB$\fP\(rq) but is shorter since there is no
+string parameter.
+This allows the useful idioms of changing to the previous
+buffer with \(lq-%*\fB$\fP\(rq, changing to the next
+buffer with \(lq%*\fB$\fP\(rq and changing the current buffer
+temporarily:
+.EX
+[* ! ...change current buffer... ! ]*
+.EE
 .TP
 .BR $ " (Escape)"
 Command-line replacement register.
diff --git a/lib/session.tes b/lib/session.tes
index d038db5..0c3ef0a 100644
--- a/lib/session.tes
+++ b/lib/session.tes
@@ -2,7 +2,7 @@
 
 ! Path of the session profile.
   Change this to save/load a custom profile !
-EQ[session.path] IQ[$HOME]/.teco_session 1EB
+[* EQ[session.path] IQ[$HOME]/.teco_session ]*
 
 @[session.save]{
   Q*U.[curbuf]
@@ -18,6 +18,7 @@ EQ[session.path] IQ[$HOME]/.teco_session 1EB
 
   EBQ[session.path]
   HK G.[session] EW EF
+  Q.[curbuf]EB
 }
 
 @[session.load]{
@@ -35,8 +36,6 @@ EQ[session.path] IQ[$HOME]/.teco_session 1EB
 @[session.git]{
   ! if there is no Git repository, session.path is left as it is !
   :EG[session.path]git rev-parse --show-toplevel"S
-    Q*U.#cb
-    EQ[session.path] ZJ -D I/.teco_session
-    Q.#cbEB
+    [* EQ[session.path] ZJ -D I/.teco_session ]*
   '
 }
diff --git a/src/qregisters.cpp b/src/qregisters.cpp
index 24ca904..846a5a4 100644
--- a/src/qregisters.cpp
+++ b/src/qregisters.cpp
@@ -229,16 +229,24 @@ QRegister::load(const gchar *filename)
 }
 
 tecoInt
-QRegisterBufferInfo::get_integer(void)
+QRegisterBufferInfo::set_integer(tecoInt v)
 {
-	tecoInt id = 1;
+	if (!ring.edit(v))
+		throw Error("Invalid buffer id %" TECO_INTEGER_FORMAT, v);
 
-	for (Buffer *buffer = ring.first();
-	     buffer != ring.current;
-	     buffer = buffer->next())
-		id++;
+	return v;
+}
 
-	return id;
+void
+QRegisterBufferInfo::undo_set_integer(void)
+{
+	current_doc_undo_edit();
+}
+
+tecoInt
+QRegisterBufferInfo::get_integer(void)
+{
+	return ring.get_id();
 }
 
 gchar *
diff --git a/src/qregisters.h b/src/qregisters.h
index cf2c644..9a7618b 100644
--- a/src/qregisters.h
+++ b/src/qregisters.h
@@ -146,12 +146,9 @@ class QRegisterBufferInfo : public QRegister {
 public:
 	QRegisterBufferInfo() : QRegister("*") {}
 
-	tecoInt
-	set_integer(tecoInt v)
-	{
-		return v;
-	}
-	void undo_set_integer(void) {}
+	/* setting "*" is equivalent to nEB */
+	tecoInt set_integer(tecoInt v);
+	void undo_set_integer(void);
 
 	tecoInt get_integer(void);
 
diff --git a/src/ring.h b/src/ring.h
index 5dc3a37..7aa4f27 100644
--- a/src/ring.h
+++ b/src/ring.h
@@ -187,6 +187,11 @@ public:
 	}
 
 	tecoInt get_id(Buffer *buffer);
+	inline tecoInt
+	get_id(void)
+	{
+		return get_id(current);
+	}
 
 	Buffer *find(const gchar *filename);
 	Buffer *find(tecoInt id);
diff --git a/teco.ini b/teco.ini
index 759124e..67ead44 100644
--- a/teco.ini
+++ b/teco.ini
@@ -49,7 +49,7 @@ Z"=
   M[session.load]
 |
   [.f
-    <:L;R 0X.f EBQ.f EB L>
+    <:L;R 0X.f [* EBQ.f ]* L>
   ].f
   -EF
 '