added a buffer session module (session.tes)

This is a simple and straight-forward implementation of
buffer sessions in SciTECO. A session is merely a SciTECO script
that opens files when executed (and restores properties).
The current session is identified by this script's filename in
Q-Register "session.path": ~/.teco_session by default.
Users may set "session.path" to manage different profiles.
An abstraction of session "names" is not provided. Users are expected
to hack these on their own.

For the common task of having one session per profile, the
"session.git" macro is provided. It set's up the current session
relative to the current Git repository.
This will create ".teco_session" files in the root of Git
repositories, that may be added to a global ignore pattern (or they
may even be versioned!)

2 files changed, 43 insertions, 1 deletions

diff --git a/lib/Makefile.am b/lib/Makefile.am
index 8a2a3eb..fef26ef 100644
--- a/lib/Makefile.am
+++ b/lib/Makefile.am
@@ -1,5 +1,5 @@
 
-dist_scitecolib_DATA = color.tes lexer.tes fnkeys.tes
+dist_scitecolib_DATA = color.tes lexer.tes session.tes fnkeys.tes
 dist_scitecolib_DATA += string.tes
 
 # Install and distribute entire directories
diff --git a/lib/session.tes b/lib/session.tes
new file mode 100644
index 0000000..d038db5
--- /dev/null
+++ b/lib/session.tes
@@ -0,0 +1,42 @@
+! Macros for saving and loading buffer sessions !
+
+! Path of the session profile.
+  Change this to save/load a custom profile !
+EQ[session.path] IQ[$HOME]/.teco_session 1EB
+
+@[session.save]{
+  Q*U.[curbuf]
+  EJ<
+    %.bEB ESGETFIRSTVISIBLELINEU.[fvline] ESGETXOFFSETU.[xoff] .U.[dot]
+    EQ.[session]
+    @I{EBQ* \.[fvline]ESSETFIRSTVISIBLELINE \.[xoff]ESSETXOFFSET \.[dot]:J^M}
+    EQ* Z"= -1U.u '
+  >
+  EQ.[session]
+  Q.u"F @I{EB -EF^M} '
+  @I{\.[curbuf]EB^M}
+
+  EBQ[session.path]
+  HK G.[session] EW EF
+}
+
+@[session.load]{
+  EJ<-EF>
+  EQ.x ENQ[session.path]
+  Z"=
+    1EB
+  |
+    :EMQ[session.path]
+  '
+}
+
+! Call this to set up the session path unique to
+  the current Git repository (if there is one) !
+@[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
+  '
+}