rajamesandClaude Opus 5.5
b5d644d498
Layer 5 of the compiler capsule. The host node is now started at QUIT and left running: it prompts, reads a line from its console with QUERY, interprets it, says " ok" or " ERROR", and goes round again. - capsule/quit.v4: QUIT and ABORT (FORTH-79), ABORT" and (ABORT") as v3 has them, ." and (.") (FORTH-79). Text is compiled as a counted string after the call; the run-time word returns to the cell after it. - INTERPRET prints v3's messages before abandoning a line: UNKNOWN WORD: 'xxx' and xxx: compile-only. - core.v4: CR SPACE COUNT TYPE, as DECOMPOSITION.md gives them. - input.v4: WORD split so that (PARSE) can take text without skipping leading delimiters (." " is an empty string); EXPECT keeps its place in memory, so six values may wait on the stack while a line is typed. - tests/test_host_quit.c: the node is fed characters and its output read; 16 sessions are transcripts of the v3 binary. QUIT stops the line from inside any word and says nothing; v3's goes on with the line and cannot be compiled. v3's compiled ABORT" crashes. Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
112 lines
4.4 KiB
Plaintext
112 lines
4.4 KiB
Plaintext
\ quit.v4 -- the prompt: lines read from the console and interpreted, one
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\ after another, for as long as the node runs; and the words that print text
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\ written in the source.
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\
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\ DECOMPOSITION.md 5.15 and 5.10: QUIT ABORT ABORT" (ABORT") ." (."). Part of
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\ the compiler capsule. Rests on all the files before it.
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\
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\ WHAT THE CONSOLE SHOWS, as v3:
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\ ok> 65 EMIT the prompt, then the line as it is typed
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\ A ok what the line printed, then " ok"
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\ ok> NOSUCH
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\ UNKNOWN WORD: 'NOSUCH'
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\ ERROR any line that sets NODE-ERROR ends so
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\ The line itself is not sent back: the terminal shows what is typed.
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\
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\ THE RETURN STACK is circular (D-2): it has no bottom to be reset to, and
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\ what is on it is simply never returned to once QUIT stops returning. So
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\ QUIT and ABORT "clear" it by jumping into the loop, from however deep. The
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\ data stack is circular too: ABORT has nothing to clear.
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\
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\ Constants the loader supplies:
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\ (Q) word address of two cells of scratch for this file
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\ ( -- ) stop compiling; forget the word being built and any open control
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\ structures. A definition that was under way stays hidden.
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: (RESET) 0 STATE a! ! (CG-RESET) CFBASE (CFP) a! ! ;
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\ ( k -- ) the loop. It is entered with what to say first -- 0 nothing,
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\ 1 " ok", anything else " ERROR" -- and never returns. Each line is
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\ interpreted with one return entry under it, this word's call of INTERPRET.
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: (REPL)
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if GO -1 + if OK
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drop (RESET) $52524520 (EMIT4) $524F (EMIT4) CR jump READ \ " ERROR"
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OK: drop $6B6F20 (EMIT4) CR jump READ \ " ok"
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GO: drop
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READ:
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$203E6B6F (EMIT4) \ "ok> "
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QUERY
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0 NODE-ERROR b! !b
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INTERPRET
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NODE-ERROR b! @b if GOOD
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drop 2 jump (REPL)
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GOOD: drop 1 jump (REPL)
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\ FORTH-79: clear the return stack, set execution mode, return control to
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\ the terminal; no message is given. The data stack is left as it is.
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header QUIT
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: QUIT (RESET) CR 0 jump (REPL)
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\ FORTH-79: clear the data and return stacks, set execution mode, return
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\ control to the terminal. As v3, the line it stops ends with " ok".
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header ABORT
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: ABORT (RESET) 1 jump (REPL)
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\ ---- text in the source ---------------------------------------------------------
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\ ." and ABORT" take the text up to the next " , which may be none at all
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\ (input.v4's (PARSE)); with no closing " it is the rest of the line. Inside a definition they lay
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\ down a call to their run-time word and, after it, the text as a counted
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\ string: the count byte and the characters, four to a cell, the last cell
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\ filled with zeros. The run-time word finds the string by the return
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\ address the call left, and returns to the cell after the string.
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\ ( -- ) lay the counted string in WBUF into the dictionary, as above.
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\ (Q)+0 how many bytes are still to go, (Q)+1 which is next.
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: (STRING,)
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(FLUSH)
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WBUF C@ 1 + (Q) a! ! 0 (Q)+1 a! !
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L: (Q) a! @ if DONE -1 + !
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(Q)+1 a! @ dup 1 + ! WBUF + C@ C,
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jump L
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DONE: drop
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P: DP b! @b 3 and if ALIGNED drop 0 C, jump P
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ALIGNED: drop ;
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\ The run time of ." : print the string after the call, go on after it.
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\ It takes the return address off before it calls anything and keeps the
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\ count there instead, so a word that prints text goes no deeper than one
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\ that calls any other word.
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: (.")
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pop 4* dup C@ \ baddr n
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L: if DONE
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push 1 + dup C@ EMIT pop -1 + jump L
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DONE: drop 4/ 1 + push ; \ the cell after the last character
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\ FORTH-79: ." text" prints the text -- now, if interpreting; when the word
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\ it is compiled into runs, if compiling.
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header ." immediate
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: DOT-QUOTE
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34 (PARSE) drop
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STATE a! @ if NOW
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drop &(.") (CALL,) jump (STRING,)
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NOW: drop WBUF COUNT jump TYPE
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\ ( flag -- ) the run time of ABORT" : if the flag is not zero print the
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\ string after the call, start a new line and ABORT; otherwise go on after
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\ the string.
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: (ABORT")
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if NO
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drop pop 4* COUNT TYPE CR jump ABORT
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NO: drop pop 4* dup C@ + 4/ 1 + push ;
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\ ( flag -- ) ABORT" text" as v3 (it is FORTH-83's, not FORTH-79's): if
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\ the flag is not zero, print the text and ABORT.
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header ABORT" immediate
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: ABORT-QUOTE
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34 (PARSE) drop
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STATE a! @ if NOW
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drop &(ABORT") (CALL,) jump (STRING,)
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NOW: drop if NO
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drop WBUF COUNT TYPE CR jump ABORT
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NO: drop ;
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