From ad2f91f329dab7fe0f8e9c45556fbf3a2bf1ce0b Mon Sep 17 00:00:00 2001
From: d6 <d_m@plastic-idolatry.com>
Date: Mon, 14 Feb 2022 16:47:36 -0500
Subject: [PATCH] fix a bunch of navigation bugs

---
 femto.tal | 109 ++++++++++++++++++++++++++++--------------------------
 1 file changed, 57 insertions(+), 52 deletions(-)

diff --git a/femto.tal b/femto.tal
index 9475c12..aec590c 100644
--- a/femto.tal
+++ b/femto.tal
@@ -195,48 +195,45 @@
 
 ( FIXME: handle long lines )
 @forward
-    ;cursor/col LDA pen-col GTH ,&skip JCN
-    ;cursor/col LDA #01 ADD ;cursor/col STA
-    ;draw-statusbar JSR2
-    ;draw-cursor JSR2
+    ;cur-pos JSR2 ;last-pos JSR2 GTH2 ,&skip JCN
+    ;cur-col JSR2 ;cur-last JSR2 GTH ,&next-line JCN
+    ;cur-col JSR2 INC ;cursor/col STA
+    ;draw-statusbar JSR2 ;draw-cursor JSR2
+    ,&skip JMP
+    &next-line #00 ;cursor/col STA ( TODO: need to ensure cursor is visible )
+               ;cursor/row LDA INC ;cursor/row STA
+               ;ensure-visible-cursor JSR2
+               ;draw-cursor JSR2
     &skip BRK
 
 ( FIXME: handle long lines )
 @back
-    ;cursor/col LDA #01 LTH ,&skip JCN
-    ;cursor/col LDA #01 SUB ;cursor/col STA
+    ;cur-col JSR2 #01 LTH ,&skip JCN
+    ;cur-col JSR2 #01 SUB ;cursor/col STA
     ;draw-statusbar JSR2
     ;draw-cursor JSR2
     &skip BRK
 
+( TODO: integrate ensure-visible-cursor to move by half-screens )
 @up
+    ;cur-line-num JSR2 #0000 EQU2 ,&done JCN
     ;cursor/row LDA #01 LTH ,&screen-up JCN
     ;cursor/row LDA #01 SUB ;cursor/row STA
     ;draw-statusbar JSR2
     ;draw-cursor JSR2 BRK
     &screen-up
-    ;buffer/offset LDA2 DUP2 ;buffer/data EQU2 ,&done JCN
-    #0001 SUB2
-    &loop DUP2 ;buffer/data EQU2 ,&complete JCN
-          #0001 SUB2 LDAk #0a NEQ ,&loop JCN
-          INC2
-    &complete ;buffer/offset STA2
-              ;buffer/line-offset LDA2k #0001 SUB2 SWP2 STA2
-              ;draw-all JSR2 BRK
-    &done POP2 BRK
+    ;cur-line-num JSR2 #0001 SUB2
+    ;jump-to-line JSR2
+    ;draw-all JSR2
+    &done BRK
 
 ( FIXME: need to handle 'end of buffer' stuff )
 @down
     ;cur-abs-row JSR2 ;last-abs-row JSR2 EQU2 ,&done JCN
-    ;cursor/row LDA pen-line GTH ,&screen-down JCN
     ;cursor/row LDA INC ;cursor/row STA
+    ;ensure-visible-cursor JSR2
     ;draw-statusbar JSR2
     ;draw-cursor JSR2 BRK
-    &screen-down
-    #00 ;rel-line JSR2 ;line-len JSR2 INC2 ( add 1 for line ending )
-    ;buffer/offset LDA2 ADD2 ;buffer/offset STA2
-    ;buffer/line-offset LDA2k INC2 SWP2 STA2
-    ;draw-all JSR2
     &done BRK
 
 @quit quit!
@@ -244,18 +241,17 @@
 @ignore BRK
 
 @insert ( c^ -> )
-    ;cursor/col LDA pen-col GTH ,&skip JCN ( FIXME )
     ;cur-pos JSR2 ;shift-right JSR2
-    ;cursor/col LDA INC ;cursor/col STA
+    ;cur-col JSR2 INC ;cursor/col STA
     ;draw-all JSR2
-    &skip BRK
+    BRK
 
-@overwrite ( c^ -> )
+( @overwrite ( c^ -> )
     ;cursor/col LDA pen-col GTH ,&skip JCN ( FIXME )
     ;cur-pos JSR2 STA
     ;cursor/col LDA #01 ADD ;cursor/col STA
     ;draw-all JSR2
-    &skip BRK
+    &skip BRK )
 
 ( TODO: handle last line )
 @newline ( c^ -> )
@@ -276,8 +272,7 @@
 @backspace ( -> )
     ;at-buffer-start JSR2 ,&skip JCN
     ;at-line-start JSR2 ,&prev-line JCN
-        ;get-col JSR2 #01 SUB ;cursor/col STA
-(        ;cursor/col LDA #01 SUB ;cursor/col STA )
+        ;cur-col JSR2 #01 SUB ;cursor/col STA
         ,&finish JMP
     &prev-line ( TODO: what if row=0 but offset>0 ? )
         ;cursor/row LDA #01 SUB ;cursor/row STA
@@ -323,7 +318,7 @@
     BRK
 
 @goto-line ( -> )
-    #0060 ;jump-to-line JSR2
+    #0016 ;jump-to-line JSR2
     ;draw-all JSR2 BRK
 
 @jump-to-line ( n* -> )
@@ -335,17 +330,23 @@
     ,&late JCN ( n n-rows/2 lines-rows )
     POP2 ,&finish JMP
     &early ( n rows/2 )
-        POP2 ,&finish JCN 
+        POP2 #0000 ,&finish JMP ( n 0000 )
     &late ( n n-rows/2 lines-rows )
-        NIP2 ,&finish JCN
+        NIP2
     &finish ( n o )
-        SUB2k STH2 DUP2
-        ;buffer/line-offset STA2
-        ;abs-line JSR2 ;buffer/offset STA2
-        #00 ;cursor/col STA
-        POP2 STH2r NIP ;cursor/row STA
+        SUB2k STH2 DUP2 ( n o o [n-o] )
+        ;buffer/line-offset STA2 ( n o [n-o] )
+        ;abs-line JSR2 ;buffer/offset STA2 ( n [n-o] )
+        #00 ;cursor/col STA ( n [n-o] )
+        POP2 STH2r NIP ;cursor/row STA ( )
         JMP2r
 
+@ensure-visible-cursor 
+    ;cursor/row LDA height LTH ,&noop JCN
+    ;cur-line-num JSR2 ;jump-to-line JSR2
+    ;draw-all JSR2
+    &noop JMP2r
+
 @refresh
     ;draw-all JSR2 BRK
 
@@ -404,7 +405,7 @@
     ansi LIT '2 emit LIT 'J emit JMP2r
 
 @draw-cursor
-    ;get-col JSR2 ;get-row JSR2
+    ;cur-col JSR2 ;cur-row JSR2
     ;term-move-cursor JSR2 JMP2r
 
 @draw-statusbar
@@ -428,7 +429,7 @@
     ;messages/lines ;print JSR2
     #20 emit
     LIT '( emit
-    ;cursor/col LDA INC ;emit-dec JSR2
+    ;cur-col JSR2 INC ;emit-dec JSR2
     LIT ', emit
     ;cur-abs-row JSR2 INC2 ;emit-dec2 JSR2
     LIT ') emit
@@ -482,6 +483,9 @@
 @cur-len ( -> n* )
     ;cur-line JSR2 ;line-len JSR2 JMP2r
 
+@cur-last ( -> n* )
+    ;cur-line JSR2 ;line-len JSR2 #0001 SUB2 NIP JMP2r
+
 @line-len ( s* -> n* )
     #0000 STH2
     &loop LDAk #00 EQU ,&end JCN
@@ -520,8 +524,11 @@
 @cur-line ( -> s* )
     ;cursor/row LDA ;rel-line JSR2 JMP2r
 
+@cur-line-num ( -> n* )
+    #00 ;cursor/row LDA ;buffer/line-offset LDA2 ADD2 JMP2r
+
 @cur-pos ( -> s* )
-    ;cur-line JSR2 #00 ;get-col JSR2 ADD2 JMP2r
+    ;cur-line JSR2 #00 ;cur-col JSR2 ADD2 JMP2r
 
 @cur-abs-row ( -> n* )
     ;buffer/line-offset LDA2 #00 ;cursor/row LDA ADD2 JMP2r
@@ -531,8 +538,7 @@
 
 @shift-right ( c^ addr* -> )
     ROT STH                 ( addr [prev^] )
-    ;buffer/limit LDA2      ( addr limit [prev^] )
-    #0001 SUB2 SWP2         ( last addr [prev^] )
+    ;last-pos JSR2 SWP2     ( last addr [prev^] )
     &loop LTH2k ,&done JCN  ( last addr [prev^] )
           LDAk STH SWPr     ( last addr [prev^ curr^] )
           DUP2 STHr         ( last addr addr prev^ [curr^] )
@@ -546,8 +552,7 @@
 
 ( TODO: change last/addr order and GTH -> LTH to remove hack )
 @shift-left ( addr* -> )
-    ;buffer/limit LDA2               ( addr limit )
-    #0001 SUB2 SWP2                  ( last addr )
+    ;last-pos JSR2 SWP2              ( last addr )
     &loop GTH2k ,&next JCN           ( last addr )
                 ,&done JMP           ( last addr )
     &next DUP2 INC2 LDAk             ( last addr addr+1 c1^ )
@@ -559,13 +564,13 @@
           #00 ;buffer/limit LDA2 STA ( ensure null termination )
     JMP2r
 
-( TODO: should be using get-col and get-row almost everywhere )
+( TODO: should be using cur-col and cur-row almost everywhere )
 ( otherwise, bugs! )
 
-@get-col
+@cur-col
     ;cursor/col LDA ;cur-len JSR2 NIP ;min JSR2 JMP2r
 
-@get-row
+@cur-row
     ;cursor/row LDA JMP2r
 
 @last-pos
@@ -577,17 +582,17 @@
 @fits-in-one-screen ( -> bool^ )
     ;buffer/line-count LDA2 ;term/rows LDA2 INC2 LTH2 JMP2r
 
-@doc-start ( -> s* ) ;buffer/data JMP2r
+( @doc-start ( -> s* ) ;buffer/data JMP2r
 @doc-limit ( -> s* ) ;buffer/limit LDA2 JMP2r
-@doc-last ( -> s* ) ;buffer/limit LDA2 #0001 SUB2 JMP2r
+@doc-last ( -> s* ) ;buffer/limit LDA2 #0001 SUB2 JMP2r )
 
-@page-start ( -> s* ) ;buffer/offset LDA2 JMP2r
+( @page-start ( -> s* ) ;buffer/offset LDA2 JMP2r
 @page-limit ( -> s* ) height ;rel-line JSR2 JMP2r
-@page-last ( -> s* ) height ;rel-line JSR2 #0001 SUB2 JMP2r
+@page-last ( -> s* ) height ;rel-line JSR2 #0001 SUB2 JMP2r )
 
-@line-start ( -> s* ) ;cursor/row LDA ;rel-line JSR2 JMP2r
+( @line-start ( -> s* ) ;cursor/row LDA ;rel-line JSR2 JMP2r
 @line-limit ( -> s* ) ;cursor/row LDA INC ;rel-line JSR2 JMP2r
-@line-last ( -> s* ) ;cursor/row LDA INC ;rel-line JSR2 #0001 SUB2 JMP2r
+@line-last ( -> s* ) ;cursor/row LDA INC ;rel-line JSR2 #0001 SUB2 JMP2r )
 
 @mod-div ( x^ y^ -> x%d x/y )
     DIVk STHk MUL SUB STHr JMP2r