feat(v4): the ROM's symbol table

(FIND) ( -- rec | 0 ), (DEFINE) ( value kind -- ) and (OPCODE) ( -- op | -1 ),
entries 3-5.  Names are refused as text.c's define refuses them, compared
case by case with text.c; a set variable may be set again.  256 hash heads,
records growing up and names growing down in dictionary space, used only
while the ROM assembles.  text.c gains the data directives #, and ", (the
ROM's language; its mnemonic and reserved-word tables are data); the
nucleus image is byte-identical.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

v4/tests/host_map.h

@@ -133,9 +133,32 @@
 #define ROM_NI       (OUT_W - 72)               /*   the next character of the token */
 #define ROM_NU       (OUT_W - 71)               /*   the value so far, unsigned */
 #define ROM_NBIG     (OUT_W - 70)               /*   1 once it has not fitted a cell */
+#define ROM_RECN     (OUT_W - 128)              /* (DEFINE): cells of symbol records used */
+#define ROM_POOLN    (OUT_W - 127)              /*   cells of the name pool used */
+#define ROM_REC      (OUT_W - 126)              /* (FIND): the record being looked at */
+#define ROM_CNT      (OUT_W - 125)              /* (DEFINE): cells in the token's name */
+#define ROM_PTR      (OUT_W - 124)              /* (SAME?), (DEFINE): where in a name */
+#define ROM_I        (OUT_W - 123)              /*   where in the token */
+#define ROM_WI       (OUT_W - 122)              /* (WALK): which entry of a table */
+/* THE ROM'S SYMBOL TABLE, used only while it assembles, in dictionary space (cleared at `start`): 256 hash heads,
+ * then records growing up -- link, name, kind, value -- and names, as counted strings, growing down from the top. */
+#define ROM_SYMH     DICT_W
+#define ROM_SYMREC   (DICT_W + 256)
+#define ROM_POOLTOP  DICT_END_W
+#define ROM_REC_LINK  0
+#define ROM_REC_NAME  1
+#define ROM_REC_KIND  2
+#define ROM_REC_VALUE 3
+#define ROM_KIND_WORD  1
+#define ROM_KIND_CONST 2
+#define ROM_KIND_MACRO 3
+#define ROM_KIND_SET   4
 /* the ROM's error codes */
 #define ROM_ERR_TOO_LONG  1                     /* a token longer than 63 characters: "name too long" */
 #define ROM_ERR_COMMENT   2                     /* a ( with no ) before the end: "comment not closed" */
+#define ROM_ERR_BAD_NAME  3                     /* an opcode, a reserved word, a label, a number or &...: "cannot be used as a name" */
+#define ROM_ERR_DEFINED   4                     /* "already defined" */
+#define ROM_ERR_NAMES     5                     /* the symbol table is full: "too many names" */
 #define WORD_DEFINED   (BUF0_W - 11)             /* the xt of the word that is told of each new entry, or 0 */
 #define WORD_FORGOTTEN (BUF0_W - 12)             /* the xt of the word that is told when entries go, or 0 */
 #define LOG_LEVEL    (BUF0_W - 5)               /* the level at or below which a message is printed */