\ log.f18 -- logging, as v3: a message has a level, and is printed if the
\ level is at or below LOG-LEVEL.
\
\ DECOMPOSITION.md 5.25: the level constants LOG-ERROR LOG-WARN LOG-INFO
\ LOG-TEST LOG-DEBUG (0 .. 4), LOG-LEVEL! LOG-LEVEL@, LOG-ERROR" ... LOG-DEBUG"
\ and LOG-ERROR-STR ... LOG-DEBUG-STR.  Part of the compiler capsule; rests
\ on core.f18, codegen.f18 and quit.f18.
\
\ WHAT IS PRINTED is v3's line without its time of day, which a node has
\ not got: the level's colour, the level's name and a colon, the colour off,
\ the text, a new line --
\     ESC [32m INFO:  ESC [0m text
\ On the mesh a message will go to the recorder's log ring (5.25); until
\ then it goes to the console.
\
\ Constants the loader supplies:
\   (LOG-LEVEL)   word address of the variable: 2, LOG-INFO, at switch-on

set HDR-NFA here  ", LOG-ERROR  #, 8  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-ERROR   0 ;
set HDR-NFA here  ", LOG-WARN  #, 8  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-WARN    1 ;
set HDR-NFA here  ", LOG-INFO  #, 8  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-INFO    2 ;
set HDR-NFA here  ", LOG-TEST  #, 8  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-TEST    3 ;
set HDR-NFA here  ", LOG-DEBUG  #, 8  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-DEBUG   4 ;

set HDR-NFA here  ", LOG-LEVEL@  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  
: LOG-LEVEL@ ( -- n )   (LOG-LEVEL) a! @ ;
\ ( n -- )   as v3: a level below 0 is 0, one above 4 is 4
set HDR-NFA here  ", LOG-LEVEL!  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  
: LOG-LEVEL!
  -if POS  drop 0 jump SET
  POS: dup -5 + -if BIG  drop jump SET
  BIG: drop drop 4
  SET: (LOG-LEVEL) a! ! ;

\ ( baddr u level -- )   the message, if the level is at or below LOG-LEVEL
: (LOG)
  dup inv (LOG-LEVEL) a! @ + 1 + -if SHOW  drop drop drop drop ;     \ LOG-LEVEL - level
  SHOW: drop
  if P0  -1 + if P1  -1 + if P2  -1 + if P3  -1 + if P4
  drop  jump OUT
  P0: drop  $31335B1B (EMIT4) $6D (EMIT4)  $4F525245 (EMIT4) $203A52 (EMIT4)  $6D305B1B (EMIT4)  jump OUT
  P1: drop  $33335B1B (EMIT4) $6D (EMIT4)  $4E524157 (EMIT4) $203A (EMIT4)  $6D305B1B (EMIT4)  jump OUT
  P2: drop  $32335B1B (EMIT4) $6D (EMIT4)  $4F464E49 (EMIT4) $203A (EMIT4)  $6D305B1B (EMIT4)  jump OUT
  P3: drop  $35335B1B (EMIT4) $6D (EMIT4)  $54534554 (EMIT4) $203A (EMIT4)  $6D305B1B (EMIT4)  jump OUT
  P4: drop  $34335B1B (EMIT4) $6D (EMIT4)  $55424544 (EMIT4) $203A47 (EMIT4)  $6D305B1B (EMIT4)  jump OUT
  OUT: TYPE  jump CR

set HDR-NFA here  ", LOG-ERROR-STR  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-ERROR-STR ( baddr u -- )   0 jump (LOG)
set HDR-NFA here  ", LOG-WARN-STR  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-WARN-STR  ( baddr u -- )   1 jump (LOG)
set HDR-NFA here  ", LOG-INFO-STR  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-INFO-STR  ( baddr u -- )   2 jump (LOG)
set HDR-NFA here  ", LOG-TEST-STR  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-TEST-STR  ( baddr u -- )   3 jump (LOG)
set HDR-NFA here  ", LOG-DEBUG-STR  #, 0  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-DEBUG-STR ( baddr u -- )   4 jump (LOG)

\ ( level -- )   the run time of LOG-xxx" : the text is after the call, as
\ for ." ; log it at that level and go on after it.
set HDR-NFA here  ", (LOG")  #, 16  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  
: (LOG")
  pop 4*  dup C@ over + 4/ 1 + push          \ level baddr      R: the cell after the text
  COUNT  ROT  jump (LOG)

\ ( level -- )   LOG-xxx" text"  logs the text -- now, if interpreting; when
\ the word it is compiled into runs, if compiling.  (Q)+3 holds the level.
: (LOG-QUOTE)
  (Q)+3 a! !  34 (PARSE) drop
  STATE a! @ if NOW
  drop  (Q)+3 a! @ (LIT,)  &(LOG") (CALL,)  jump (STRING,)
  NOW: drop  WBUF COUNT  (Q)+3 a! @  jump (LOG)
set HDR-NFA here  ", LOG-ERROR"  #, 1  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-ERROR-QUOTE   0 jump (LOG-QUOTE)
set HDR-NFA here  ", LOG-WARN"  #, 1  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-WARN-QUOTE    1 jump (LOG-QUOTE)
set HDR-NFA here  ", LOG-INFO"  #, 1  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-INFO-QUOTE    2 jump (LOG-QUOTE)
set HDR-NFA here  ", LOG-TEST"  #, 1  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-TEST-QUOTE    3 jump (LOG-QUOTE)
set HDR-NFA here  ", LOG-DEBUG"  #, 1  #, HDR-NFA  #, HDR-LINK  set HDR-LINK here  : LOG-DEBUG-QUOTE   4 jump (LOG-QUOTE)