Files
LithosAnanake/capsules/v4/rom/in.f18
T
rajamesandClaude Opus 5.5 0f82d8c22a feat(v4): mkrom -- the ROM built off the node; it reads tokens
The ROM's source is F18 code in capsules/v4/rom, assembled off the node by
v4/tools/mkrom.c with the memory map's constants from v4/tools/mkmap.c
(MACHINE.md 2).  main.f18 is the entry table payloads call through (2.1);
in.f18 reads the console and splits it into tokens exactly as text.c does,
the token held packed as a counted string.  The ROM's state is a reserved
area of the map (host_map.h ROM_*).  text.c gains the constant directive,
so the off-node assembler and the ROM speak one language.  The map also
names (NUMBER)'s state, for the next task.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-10-15 11:49:05 -04:00

106 lines
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\ in.f18 -- the ROM's input: characters from the console, and tokens.
\
\ The text the ROM assembles arrives at the console's receive registers,
\ a character at a time. The end of it is EOT (4), which the loader sends
\ after the last blob. A token is what v4/src/text.c's next_token makes
\ of the same text: blanks are space, tab, CR and LF; a token is at most 63
\ characters; `\` as a whole token skips to the end of the line, and `(` as a
\ whole token to the next `)`.
\
\ State, in the ROM's area of the memory map (MACHINE.md 2.1):
\ (TOK) the token, as a counted string: its count byte, then its
\ characters, four to a cell, low byte first, zero-padded --
\ the form `",` lays down and (FIND) compares; 16 cells
\ (TOKN) its length
\ (PEEK) a character put back, plus one; 0: none
\ (LINE) how many new lines have been read
\ (EOF) non-zero once EOT has been read
\ (FAILED) 0, or the code of the error that stopped the ROM
\ (ERRLINE) (LINE) when it failed
\ Every routine here uses A.
\ ( -- c ) wait for a character, then take it
: (KEY)
W: CONSOLE-STATUS a! @ if Z drop CONSOLE-RX a! @ ;
Z: drop jump W
\ ( -- c ) the character put back, if there is one; else the next
: (GETC)
(PEEK) a! @ if NONE 0 ! -1 + ;
NONE: drop jump (KEY)
\ ( c -- ) put a character back, to be the next one read
: (BACK) 1 + (PEEK) a! ! ;
\ ( -- ) one more new line
: (LF+) (LINE) a! @ 1 + ! ;
\ ( code -- ) stop with an error, noting the line
: (FAIL) (FAILED) a! ! (LINE) a! @ (ERRLINE) a! ! ;
\ ( c -- ) one more character of the token: byte (TOKN)+1 of (TOK), into
\ a cell whose byte there is still zero
: (PUT)
(TOKN) a! @ 1 +
dup 2/ 2/ (TOK) + push
3 and
S: if SD push 2* 2* 2* 2* 2* 2* 2* 2* pop -1 + jump S
SD: drop pop a! @ xor !
(TOKN) a! @ 1 + ! ;
\ ( i -- c ) character i of the token, from 0
: (CHAR@)
1 + dup 2/ 2/ (TOK) + a! @
push 3 and
S: if SD -1 + pop 2/ 2/ 2/ 2/ 2/ 2/ 2/ 2/ push jump S
SD: drop pop 255 and ;
\ ( -- len ) the next token into (TOK), its length into (TOKN). 0: the end,
\ or an error, which is in (FAILED).
: (TOKEN)
(EOF) a! @ if GO drop 0 ;
GO: drop
SKIP: (GETC)
dup 4 xor if END
drop dup 10 xor if NL
drop dup 32 xor if SP
drop dup 9 xor if SP
drop dup 13 xor if SP
drop 0 (TOKN) a! !
(TOK) a! 15 FOR 0 !+ NEXT
READ: (TOKN) a! @ 63 xor if LONG
drop (PUT) (GETC)
dup 4 xor if TEND
drop dup 10 xor if TEND
drop dup 32 xor if TEND
drop dup 9 xor if TEND
drop dup 13 xor if TEND
drop jump READ
TEND: drop (BACK)
(TOKN) a! @ (TOK) a! @ xor !
(TOKN) a! @ 1 xor if ONE
drop (TOKN) a! @ ;
ONE: drop 0 (CHAR@)
dup 92 xor if BSL
drop dup 40 xor if PAREN
drop drop 1 ;
BSL: drop drop
B1: (GETC)
dup 10 xor if BEND
drop dup 4 xor if BEND
drop drop jump B1
BEND: drop (BACK) jump SKIP
PAREN: drop drop
P1: (GETC)
dup 41 xor if PCLOSE
drop dup 10 xor if PNL
drop dup 4 xor if PEOF
drop drop jump P1
PNL: drop drop (LF+) jump P1
PCLOSE: drop drop jump SKIP
PEOF: drop drop ERR-COMMENT (FAIL) 0 ;
END: drop drop 1 (EOF) a! ! 0 ;
NL: drop drop (LF+) jump SKIP
SP: drop drop jump SKIP
LONG: drop drop ERR-TOO-LONG (FAIL) 0 ;