From 910159f7abcc39bd61d13242d6b5927cf726fba2 Mon Sep 17 00:00:00 2001
From: Luxferre <lux@ferre>
Date: Sun, 14 Jun 2026 09:28:29 +0300
Subject: [PATCH] updated listing/saving algos

---
 lttb-impl-notes.md | 17 ++++++++++++-----
 lttb.tcl           |  8 ++++----
 2 files changed, 16 insertions(+), 9 deletions(-)

diff --git a/lttb-impl-notes.md b/lttb-impl-notes.md
index 603d1f3..819ebf1 100644
--- a/lttb-impl-notes.md
+++ b/lttb-impl-notes.md
@@ -226,6 +226,16 @@ Run the program currently loaded into the working memory.
 
 Output program listing.
 
+Two algorithms are provided: for the platforms that can extract associative array keys and for those that cannot.
+
+Algorithm 1:
+
+1. Extract key list `LNOS` from `PROGMEM` associative array. Sort the list in the integer numeric order.
+2. Fetch the next key `LNO` from `LNOS`. Upon exhaustion, return from the routine.
+3. If `PROGMEM[LNO]` is not empty, output the value of `LNO`, TAB character (ASCII 9) and `PROGMEM[LNO]` with a newline at the end. Go to step 2.
+
+Algorithm 2:
+
 1. Set `I = 1`.
 2. If `PROGMEM[I]` exists and is not empty, output the value of `I`, TAB character (ASCII 9) and `PROGMEM[I]` with a newline at the end.
 3. Increment `I` by 1.
@@ -263,11 +273,8 @@ Program saving routine into external storage media. The provided algorithm works
 1. Prompt the user for a file name/path `FNAME`.
 2. If the file name/path isn't writable, notify the user about this error and return.
 3. Open a file handle `FH` for writing into the file under the path `FNAME`.
-4. Set `I = 1`.
-5. If `PROGMEM[I]` exists and is not empty, write the value of `I`, space character (ASCII 32) and `PROGMEM[I]` with a newline at the end to the file handle `FH`.
-6. Increment `I` by 1.
-7. If `I > 0` and `I < 32768`, go to step 5.
-8. Close the handle `FH` and notify the user about successful program saving.
+4. Perform the algorithm described for the `LIST` routine, but using the specified file handle instead of standard output and space character (ASCII 32) instead of TAB character (ASCII 9).
+5. Close the handle `FH` and notify the user about successful program saving.
 
 ## Closing notes
 
diff --git a/lttb.tcl b/lttb.tcl
index 827adf9..1f89efe 100755
--- a/lttb.tcl
+++ b/lttb.tcl
@@ -245,8 +245,8 @@ proc lttb_EN {stmt} {
 
 proc int_LIST {} {
   global progmem
-  loop i 1 32768 {
-    if {[dict exists $progmem $i] && [string length $progmem($i)]} {
+  foreach i [lsort -integer [dict keys $progmem]] {
+    if {$progmem($i) ne {}} {
       puts [format "%d\t%s" $i $progmem($i)]
     }
   }
@@ -292,8 +292,8 @@ proc int_SAVE {} {
   stdout flush
   stdin gets fname
   set fh [open $fname w]
-  loop i 1 32768 {
-    if {[dict exists $progmem $i]} {
+  foreach i [lsort -integer [dict keys $progmem]] {
+    if {$progmem($i) ne {}} {
       $fh puts [format {%d %s} $i $progmem($i)]
     }
   }