From df70eb084862eb488520993df53f10e7e68953ad Mon Sep 17 00:00:00 2001
From: d6 <d_m@plastic-idolatry.com>
Date: Sat, 26 Mar 2022 15:29:00 -0400
Subject: [PATCH] converted to absolute cursor, fixed a lot of bugs

---
 femto.tal | 105 +++++++++++++++++++++++++-----------------------------
 1 file changed, 48 insertions(+), 57 deletions(-)

diff --git a/femto.tal b/femto.tal
index 5f66815..be62f94 100644
--- a/femto.tal
+++ b/femto.tal
@@ -281,14 +281,10 @@
 
 @up ( -> )
     ;cur-abs-row JSR2 #0000 EQU2 ,&done JCN
-    ;cur-rel-row JSR2 #0001 LTH2 ,&screen-up JCN
     ;dec-row JSR2
+    ;ensure-visible-cursor JSR2
     ;draw-statusbar JSR2
     &done ;draw-cursor JSR2 BRK
-    &screen-up
-    ;cur-abs-row JSR2 #0001 SUB2
-    ;jump-to-line JSR2
-    ;draw-all JSR2 BRK
 
 @down ( -> )
     ;cur-abs-row JSR2 ;last-abs-row JSR2 EQU2 ,&done JCN
@@ -297,31 +293,42 @@
     ;draw-statusbar JSR2
     &done ;draw-cursor JSR2 BRK
 
+@center-view
+    ;term/rows LDZ2 INC2 #0002 DIV2 STH2k
+    .cursor/row LDZ2 LTH2 ,&standard JCN
+        POP2r
+        #0000 .buffer/line-offset STZ2
+        ;data .buffer/offset STZ2
+        ,&done JMP
+    &standard
+        .cursor/row LDZ2 STH2r SUB2
+        DUP2 .buffer/line-offset STZ2
+        ;abs-line JSR2 .buffer/offset STZ2
+    &done
+        ;draw-all JSR2 BRK
+
 @page-up ( -> )
-    ;bof-is-visible JSR2 ,&at-bof JCN
-        .buffer/line-offset LDZ2
-        .term/rows LDZ2 #0003 SUB2
-    LTH2k ,&near-bof JCN
-        SUB2 DUP2 ;abs-line JSR2 .buffer/offset STZ2
-                                 .buffer/line-offset STZ2
-        ;ensure-visible-cursor JSR2
-        ;draw-all JSR2 BRK
-    &near-bof POP2 POP2
+    .term/rows LDZ2 #0002 SUB2 STH2k
+    .buffer/line-offset LDZ2 LTH2 ,&move-full JCN
+        POP2r
         ;zero-row JSR2
         #0000 .cursor/col STZ2
+        ,&done JMP
+    &move-full
+        .cursor/row LDZ2 STH2kr SUB2 .cursor/row STZ2
+        .buffer/line-offset LDZ2 STH2r SUB2
+                  DUP2 .buffer/line-offset STZ2
+        ;abs-line JSR2 .buffer/offset STZ2
+    &done
         ;draw-all JSR2 BRK
-    &at-bof
-        ;zero-row JSR2
-        #0000 .cursor/col STZ2
-        ;draw-cursor JSR2 BRK
 
 @page-down
     ;eof-is-visible JSR2 ,&near-eof JCN
-        .buffer/line-offset LDZ2
-        .term/rows LDZ2 ADD2 #0003 SUB2
-        DUP2 ;abs-line JSR2 .buffer/offset STZ2
-                            .buffer/line-offset STZ2
-        ;ensure-visible-cursor JSR2
+        .term/rows LDZ2 #0002 SUB2 STH2k
+        .buffer/line-offset LDZ2 ADD2
+                      DUP2 .buffer/line-offset STZ2
+            ;abs-line JSR2 .buffer/offset STZ2
+        .cursor/row LDZ2 STH2r ADD2 .cursor/row STZ2
         ;draw-all JSR2 BRK
     &near-eof
         .buffer/line-count LDZ2 #0001 SUB2 ;set-abs-row JSR2
@@ -411,23 +418,6 @@
     ;delete JMP2
     &skip BRK
 
-( @backspace ( -> )
-    #01 .state/modified STZ
-    ;at-buffer-start JSR2 ,&skip JCN
-    ;at-line-start JSR2 ,&prev-line JCN
-        ;cur-col JSR2 #0001 SUB2 .cursor/col STZ2
-        ,&finish JMP
-    &prev-line
-        ;cur-abs-row JSR2 #0001 SUB2
-        ;jump-to-line JSR2 ( TODO: fix weird eof behavior )
-        ;cur-len JSR2 .cursor/col STZ2
-        .buffer/line-count LDZ2k #0001 SUB2 ROT STZ2
-    &finish
-        ;cur-pos JSR2 ;shift-left JSR2
-        ;draw-all JSR2 BRK
-    &skip
-        ;draw-cursor JSR2 BRK )
-
 @backspace-prompt ( -> )
     #00 .tmp/pos LDZ2 #0001 SUB2 ( 0 pos-1 )
     STH2k STA ( data[pos-1] <- 0 )
@@ -450,12 +440,11 @@
     #01 .state/saw-esc STZ BRK
 
 @goto-end ( -> )
-    ;more-than-one-screen JSR2 ,&large JCN
-        .buffer/line-count LDZ2 #0001 SUB2 .cursor/row STZ2
-        #0000 ,&continue JMP
-    &large
-        .term/rows LDZ2 #0001 SUB2 .cursor/row STZ2
-        .buffer/line-count LDZ2 .term/rows LDZ2 SUB2
+    .buffer/line-count LDZ2 #0001 SUB2 .cursor/row STZ2
+    .buffer/line-count LDZ2 .term/rows LDZ2 LTH2k ,&use-zero JCN
+        SUB2 #0002 ADD2 ,&continue JMP
+    &use-zero
+        POP2 POP2 #0000
     &continue
         DUP2 .buffer/line-offset STZ2
         ;abs-line JSR2 .buffer/offset STZ2
@@ -508,7 +497,7 @@
         BRK
 
 @jump-to-line ( n* -> )
-    .term/rows LDZ2 #0002 DIV2 LTH2k ( n rows/2 n<rows/2? ) ,&early JCN
+    .term/rows LDZ2 INC2 #0002 DIV2 LTH2k ( n rows/2 n<rows/2? ) ,&early JCN
     OVR2 SWP2 SUB2 ( n n-rows/2 )
     .buffer/line-count LDZ2 ( n n-rows/2 lines )
     .term/rows LDZ2 SUB2 ( n n-rows/2 lines-rows )
@@ -524,7 +513,8 @@
         .buffer/line-offset STZ2 ( n o [n-o] )
         ;abs-line JSR2 .buffer/offset STZ2 ( n [n-o] )
         #0000 .cursor/col STZ2 ( n [n-o] )
-        POP2 STH2r .cursor/row STZ2
+(        POP2 STH2r .cursor/row STZ2 )
+        POP2r .cursor/row STZ2
         JMP2r
 
 @ensure-visible-cursor
@@ -533,9 +523,6 @@
     ;draw-all JSR2
     &noop JMP2r
 
-@refresh
-    ;draw-all JSR2 BRK
-
 @debug
     ;messages/rel-line-error ;error! JMP2
 
@@ -697,7 +684,7 @@
     .Console/read DEI #05 EQU ( C-e ) ;eol JCN2
     .Console/read DEI #06 EQU ( C-f ) ;forward JCN2
     .Console/read DEI #09 EQU ( \t )  ;insert-tab JCN2
-    .Console/read DEI #0c EQU ( C-l ) ;refresh JCN2
+    .Console/read DEI #0c EQU ( C-l ) ;center-view JCN2
     .Console/read DEI #0d EQU ( \r  ) ;newline JCN2
     .Console/read DEI #0e EQU ( C-n ) ;down JCN2
     .Console/read DEI #0f EQU ( C-o ) ;save JCN2
@@ -962,7 +949,9 @@
     &not-found ;messages/rel-line-error ;error! JMP2
 
 @cur-line ( -> s* )
-    ;cur-rel-row JSR2 ;rel-line JMP2
+    ;cur-rel-row JSR2 .term/rows LDZ2 LTH2 ,&safe JCN
+    .cursor/row LDZ2 ;abs-line JMP2    
+    &safe ;cur-rel-row JSR2 ;rel-line JMP2
 
 @cur-pos ( -> s* )
     ;cur-line JSR2 ;cur-col JSR2 ADD2 JMP2r
@@ -1013,10 +1002,12 @@
     &tabs INC2 .config/tab-width LDZ2 STH2 ADD2r ,&loop JMP
 
 @cur-rel-row ( -> row* )
-    .cursor/row LDZ2 JMP2r
+(    .cursor/row LDZ2 JMP2r )
+    .cursor/row LDZ2 .buffer/line-offset LDZ2 SUB2 JMP2r
 
 @set-abs-row ( n* -> )
-    .buffer/line-offset LDZ2 SUB2 .cursor/row STZ2 JMP2r
+(    .buffer/line-offset LDZ2 SUB2 .cursor/row STZ2 JMP2r )
+    .cursor/row STZ2 JMP2r
 
 ( @set-rel-row ( n* -> )
     .cursor/row STZ2 JMP2r )
@@ -1036,8 +1027,8 @@
 @last-pos ( -> addr* )
     .buffer/limit LDZ2 #0001 SUB2 JMP2r
 
-@more-than-one-screen ( -> bool^ )
-    .buffer/line-count LDZ2 .term/rows LDZ2 GTH2 JMP2r
+( @more-than-one-screen ( -> bool^ )
+    .buffer/line-count LDZ2 .term/rows LDZ2 GTH2 JMP2r )
 
 ( @fits-in-one-screen ( -> bool^ )
     .buffer/line-count LDZ2 .term/rows LDZ2 INC2 LTH2 JMP2r )