Files
LithosAnanake/proof/StarForth_Editor_Words.thy
T
Robert Allan James cf205ca04a proof/: add StarForth_Editor_Words.thy and StarForth_Format_Words.thy
editor_words.c: zero tractable words (first such file in this sweep) --
every word routes through the same deferred block-window cache as
block_words.c, and EDIT is an interactive stdin/stdout REPL loop, not a
single-step transition.

format_words.c: 17 of 19 registered words modeled (# and #S deferred,
multi-precision division out of scope). Two genuine C findings recorded:
(1) DECIMAL/HEX/OCTAL write only the FORTH-visible memory cell at
base_addr, never the separate vm->base host-mirror field that number
OUTPUT words actually read -- proved formally
(decimal_does_not_change_vm_base et al.), so HEX/OCTAL/DECIMAL silently
never affect printed output, only parsed input. (2) ? and DUMP cast the
popped cell directly to a host pointer and dereference it, bypassing
vm_addr_ok entirely -- an out-of-VM-bounds read, not modeled since it
isn't a vm->memory access at all.

Adds base_addr/hold_addr/hold_pos to vm_state (StarForth_Base.thy),
matching the scr_addr/here pattern from earlier files.
2026-08-14 14:03:05 -04:00

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theory StarForth_Editor_Words
imports StarForth_Base
begin
(* =========================================================================
POST-12: Editor Words
Mirrors: src/word_source/editor_words.c (4 registered words)
SCOPE, decided 2026-08-14: none of the 4 registered words are modeled --
the first file in this sweep with zero tractable words (block_words.c,
the previous "worst case", still had SCR). Every word here routes
through the shared helper `line_ptr`, which calls straight into the
same block-subsystem cache StarForth_Block_Words.thy already documented
as out of scope: `blk_get_buffer`/`blk_is_valid` (block_subsystem.h),
backed by real disk I/O, none of it in vm_state. There is no analogue
of SCR here -- editor_words.c's `current_scr` *dereferences* memory at
`vm->scr_addr` (`vm_load_cell(vm, vm->scr_addr)`) rather than pushing
the address itself, so even the SCR-range guard clauses ultimately gate
entry into `line_ptr`, which is where every word's real effect lives.
L ( u -- ) : line_ptr + print_line_64 (console I/O).
S ( c-addr len u -- ) : line_ptr + memcpy into the block buffer (disk-
backed memory, not vm_state) + mark_buffer_dirty
(block-window cache, same gap as block_words.c).
SHOW ( -- ) : line_ptr x16 (one per line) + printf (console I/O).
EDIT ( u -- ) : an interactive stdin/stdout REPL loop (fgets in a
`for (;;)`) that dispatches to L/S/SHOW plus
save_all_buffers (block-window cache) -- not a
single-step vm_state transition in any sense the rest
of this suite's words are, same category as
block_words.c's LOAD/THRU (recursive/looping, not a
leaf effect).
Nothing new added to vm_state or StarForth_Base.thy for this file --
there is nothing self-contained enough to need it.
======================================================================== *)
lemma l_not_modelled: True \<comment> \<open>L: line_ptr (block-window cache + blk_is_valid) + console I/O.\<close>
by simp
lemma s_not_modelled: True \<comment> \<open>S: line_ptr + memcpy into block buffer + mark_buffer_dirty.\<close>
by simp
lemma show_not_modelled: True \<comment> \<open>SHOW: line_ptr x16 + console I/O.\<close>
by simp
lemma edit_not_modelled: True \<comment> \<open>EDIT: interactive stdin/stdout REPL loop, not a single-step transition.\<close>
by simp
end