[245] 2022-07-05 16:22:37 FrancoisLaagel wrote:

requestClarification - :NONAME Primitives

Are these supposed to support RECURSE?

[r831] 2022-06-25 10:16:33 StefanK replies:

proposal - minimalistic core API for recognizers

A small remark to the POSTPONE test.

We can factor postpone in two parts with state-execute similiar to base-execute:

   : state-execute ( xt s -- )  state@ >r state ! catch r> state ! throw ;
   : POSTPONE ( "name" -- ) parse-name forth-recognizer -2 state-execute ; immediate

That's not very difficult anymore.

[r832] 2022-07-04 21:02:03 StefanK replies:

proposal - minimalistic core API for recognizers

IMHO the idea to use a deferred forth-recognize is good and more flexible than a stack of recognizers. But the translator xt makes postpone more difficult. But we can factor postpone into two parts. One that restores the stack contents at runtime similar to lit,, and one that does the compilation. If we use rectype, similar to the proposal of recognizers from 2018, but with lit, as third method, we get an easy postpone and '. Here, we can reuse the compile method directly by the second factor of postpone.

variable state

: translate>interpret @ ;
: translate>compile   cell+ @ ;
: translate>lit,      cell+ cell+ @ ;
\ Well, its translate>*lit, in fact; i.e. regenerate ( i*x ) at runtime.

Defer forth-recognizer ( addr u -- i*x translator / notfound )
Defer perform ( i*x translator -- j*x )

: perform>interpret translate>interpret execute ;
: perform>compile   translate>compile   execute ;

: on  -1 swap ! ;
: off  0 swap ! ;

: [ ['] perform>interpret is perform state off ; IMMEDIATE
: ] ['] perform>compile   is perform state on ;

\ alternativly:
\ :noname is perform state ; dup
\ : [ ['] perform>interpret [ compile, ]  off ; IMMEDIATE
\ : ] ['] perform>compile   [ compile, ]  on ;
\ another alternative:
\ : perform state @ IF translator>compile ELSE translator>interpret THEN execute ;

' [ execute \ initialize state and perform
: interpret ( i*x -- j*x )
  BEGIN
      ?stack parse-name dup  WHILE
      forth-recognizer perform
  REPEAT ;

: lit,  ( n -- )  lit lit , ,  ; \ or postpone literal
: throw-13 -13 throw ;

: translator ( xt-*lit, xt-compile  xt-interpret "name" -- )
    create , , , ;

' throw-13 dup dup translator notfound

' lit,
:noname ( nt -- xt-execute | xt-compile, ) dup >cfa swap immediate? IF execute ELSE compile, THEN ;
:noname ( i*x nt -- j*x ) >cfa execute ;
translator translate-nt

' lit,
' lit,
:name ; \ noop
translator translate-const-cell

: rec-nt ( addr u -- nt translate-nt | notfound )
  forth-wordlist find-name-in dup IF  translate-nt  ELSE  drop notfound  THEN ;
: rec-num ( addr u -- n translate-const-cell | notfound )
  0. 2swap >number 0= IF  2drop translate-const-cell  ELSE  2drop drop notfound  THEN ;

: minimal-recognizer ( addr u -- nt nt-translator | n num-translator | notfound )
  2>r 2r@ rec-nt dup notfound = IF  drop 2r@ rec-num  THEN  2rdrop ;

' minimal-recognizer is forth-recognizer

\ simple postpone
: postpone ( "name" -- )
    parse'n'recognize
    dup translator>compile >r translator>lit, execute r> compile,
; IMMEDIATE

\ postpone optimized for immedate words
: postpone ( "name" -- ) \ optimized for immediate words
    parse'n'recognize \ ( i*x translator )
    dup translate-nt = IF ( nt translator )
        over immediate? IF drop >cfa compile, exit THEN
    THEN
    dup translator>compile >r translator>lit, execute r> compile, ;
; IMMEDIATE

: ' ( "name" -- xt ) parse'n'recognize translate-nt <> IF throw-13 THEN >cfa ; IMMEDIATE