DEFINITION MODULE TermCfg ;

(* Terminal escape sequences, loaded from a TEXT file.  This is the whole
   point of the module: the shell never patches its own binary (TINST's
   approach); it reads a configuration at startup.

   FILE FORMAT - plain text, one KEY=value per line:

      ; a comment
      NAME=ANSI
      CLEAR=\e[2J\e[H
      HOME=\e[H
      GOTO=\e[%r;%cH
      NORMAL=\e[0m
      MARKED=\e[1;7m
      BEEP=^G

   `;' at the start of a line starts a comment.  Blanks around the key and
   value are ignored.  The key is case-insensitive.

   Values are DECODED, so the file stays readable and editable:

      \e  or \E   ESC (27)        \r  CR (13)      \n  LF (10)
      \t  TAB (9)                 \\  a backslash
      ^X          control-X (X uppercased, minus 64), e.g. ^G = BEL (7)

   GOTO may contain %r and %c; the shell substitutes the decimal row and
   column there (1-based, as TP3's GotoXY is).  %% is a literal percent.

   A missing file, or a line with no '=', sets ok to FALSE and leaves the
   defaults (and anything read before the bad line) in place - never a
   silently half-written screen. *)

CONST
   MaxSeq  = 63 ;
   MaxName = 31 ;

TYPE
   Cfg = RECORD
      name   : ARRAY [0..MaxName] OF CHAR ;
      clear  : ARRAY [0..MaxSeq] OF CHAR ;
      home   : ARRAY [0..MaxSeq] OF CHAR ;
      moveTo : ARRAY [0..MaxSeq] OF CHAR ;   (* GOTO: %r, %c *)
      normal : ARRAY [0..MaxSeq] OF CHAR ;
      marked : ARRAY [0..MaxSeq] OF CHAR ;
      beep   : ARRAY [0..MaxSeq] OF CHAR ;
   END ;

PROCEDURE ParseValue (src : ARRAY OF CHAR ; VAR dst : ARRAY OF CHAR) ;
(* decode one value's escapes into dst: the same rules as a file's value, so
   a caller building a Cfg in memory spells it exactly as the file would. *)

PROCEDURE Default (VAR c : Cfg) ;
(* the ANSI set - what the shell used before there was a config file *)

PROCEDURE Load (path : ARRAY OF CHAR ; VAR c : Cfg ; VAR ok : BOOLEAN) ;
(* Default(c), then every KEY=value in path.  ok is FALSE if the file could
   not be opened or a line is malformed. *)

END TermCfg.