Improve text encodings on Atari

docs/lang/text.md

@@ -30,6 +30,10 @@
 * `iso_de`, `iso_no`, `iso_se`, `iso_yu` – various variants of ISO/IEC-646
  
 * `iso_dk`, `iso_fi` – aliases for `iso_no` and `iso_se` respectively
+ 
+* `atascii` or `atari` – ATASCII as seen on Atari 8-bit computers
+ 
+* `atasciiscr` or `atariscr` – screencodes used by Atari 8-bit computers
 
 When programming for Commodore,
 use `pet` for strings you're printing using standard I/O routines
@@ -65,11 +69,13 @@ control codes for changing the text background color
 
 ##### Escape sequence availability
 
-Encoding | new line | braces | backspace | cursor movement | text colour and reverse | background colour
---|--|--|--|--|--|--
-`pet`              | yes | no  | no  | yes | yes | no
-`petscr`           | no  | no  | no  | no  | no  | no
-`sinclair`         | yes | yes | no  | yes | yes | yes
-`ascii`, `iso_*`   | yes | yes | yes | no  | no  | no
-`apple2`           | no  | yes | no  | no  | no  | no
+Encoding | new line | braces | backspace | cursor movement | text colour and reverse | background colour  
+--|--|--|--|--|--|--  
+`pet`              | yes | no  | no  | yes | yes | no  
+`petscr`           | no  | no  | no  | no  | no  | no  
+`sinclair`         | yes | yes | no  | yes | yes | yes  
+`ascii`, `iso_*`   | yes | yes | yes | no  | no  | no  
+`apple2`           | no  | yes | no  | no  | no  | no  
+`atascii`          | yes | no  | yes | yes | no  | no  
+`atasciiscr`       | no  | no  | no  | no  | no  | no  
 all the rest       | yes | yes | no  | no  | no  | no

include/a8.ini

@@ -2,6 +2,7 @@
 arch=strict
 modules=a8_kernel,default_panic,stdlib
 encoding=atascii
+screen_encoding=atasciiscr
 
 [allocation]
 ; TODO

src/main/scala/millfork/parser/TextCodec.scala

@@ -139,6 +139,8 @@ object TextCodec {
       case (_, "petscr") => TextCodec.CbmScreencodes
       case (_, "atascii") => TextCodec.Atascii
       case (_, "atari") => TextCodec.Atascii
+      case (_, "atasciiscr") => TextCodec.AtasciiScreencodes
+      case (_, "atariscr") => TextCodec.AtasciiScreencodes
       case (_, "bbc") => TextCodec.Bbc
       case (_, "sinclair") => TextCodec.Sinclair
       case (_, "apple2") => TextCodec.Apple2
@@ -347,7 +349,25 @@ object TextCodec {
     "\ufffd" * 11 +
       0x20.to(0x5f).map(_.toChar).mkString +
       "♢abcdefghijklmnopqrstuvwxyz♠|",
-    Map('♥' -> 0, '·' -> 0x14), Map.empty, MinimalEscapeSequencesWithBraces + ("n" -> List(0x9b))
+    Map('♥' -> 0, '·' -> 0x14), Map.empty, MinimalEscapeSequencesWithoutBraces ++ Seq(
+      "n" -> List(0x9b),
+      "up" -> List(0x1c),
+      "down" -> List(0x1d),
+      "left" -> List(0x1e),
+      "right" -> List(0x1f),
+      "b" -> List(0x7e),
+    )
+  )
+
+  val AtasciiScreencodes = new TextCodec("ATASCII-Screen",
+    0x20.to(0x3f).map(_.toChar).mkString +
+      0x40.to(0x5f).map(_.toChar).mkString +
+      "♡" +
+      "\ufffd" * 15 +
+      "♣\ufffd–\ufffd•" +
+      "\ufffd" * 7 + "↑↓←→"+
+      "♢abcdefghijklmnopqrstuvwxyz♠|",
+    Map('♥' -> 0x40, '·' -> 0x54), Map.empty, MinimalEscapeSequencesWithoutBraces
   )
 
   val Bbc = new TextCodec("BBC",