refactor, encapsulateHEADmain

1 files changed, 20 insertions, 87 deletions

diff --git a/source/state.cpp b/source/state.cpp
index 03ad95d..63c633a 100644
--- a/source/state.cpp
+++ b/source/state.cpp
@@ -1,5 +1,5 @@
 // sprit-forth: A portable subroutine-threaded Forth.
-// Copyright (C) 2023  Clyne Sullivan <clyne@bitgloo.com>
+// Copyright (C) 2024  Clyne Sullivan <clyne@bitgloo.com>
 //
 // This library is free software; you can redistribute it and/or modify it
 // under the terms of the GNU Library General Public License as published by
@@ -18,108 +18,41 @@
 #include "core.hpp"
 #include "state.hpp"
 
-#include <csetjmp>
 #include <cstring>
 
-FuncList IP = nullptr;
-std::array<Cell, DictSize> DICT;
+State Forth;
 
-Cell& BASE   = DICT[DIdxBase];
-Cell& HERE   = DICT[DIdxHere];
-Cell& LATEST = DICT[DIdxLatest];
-Cell& STATE  = DICT[DIdxState];
+void State::push(Cell value) {
+    if (sp >= ds.end())
+        Exec.terminate(Error::push);
 
-static std::jmp_buf jmpbuf;
-static Cell *SP = DICT.data() + DICT.size() - DS;
-static Cell *RP = DICT.data() + DICT.size() - DS - RS;
-
-void push(Cell value) {
-    if (SP >= DICT.data() + DICT.size())
-        std::longjmp(jmpbuf, static_cast<int>(Error::push));
-
-    *++SP = value;
+    *++sp = value;
 }
 
-Cell pop() {
-    if (SP - 1 < DICT.data() + DICT.size() - DS)
-        std::longjmp(jmpbuf, static_cast<int>(Error::pop));
+Cell State::pop() {
+    if (sp - 1 < ds.begin())
+        Exec.terminate(Error::pop);
 
-    return *SP--;
+    return *sp--;
 }
 
-Cell *sp() {
-    return SP;
-}
-
-void rpush(Cell value) {
-    if (RP >= DICT.data() + DICT.size() - DS)
-        std::longjmp(jmpbuf, static_cast<int>(Error::rpush));
-
-    *++RP = value;
-}
-
-Cell rpop() {
-    if (RP - 1 < DICT.data() + DICT.size() - DS - RS)
-        std::longjmp(jmpbuf, static_cast<int>(Error::rpop));
-
-    return *RP--;
-}
+void State::rpush(Cell value) {
+    if (rp >= rs.end())
+        Exec.terminate(Error::rpush);
 
-Cell *rp() {
-    return RP;
+    *++rp = value;
 }
 
-Error executor(FuncList *list)
-{
-    auto result = static_cast<Error>(setjmp(jmpbuf));
-    FuncList body;
-
-    if (static_cast<int>(result) == 0) {
-        result = Error::none;
-
-        // We are given the pointer to a list of function pointers.
-        // Dereference once to retrieve the function pointer list.
-        // We do not work with IP initially since it needs to be set to zero if
-        // this is a top-level call/execution.
-        body = *list;
+Cell State::rpop() {
+    if (rp - 1 < rs.begin())
+        Exec.terminate(Error::rpop);
 
-        // Enter the execution loop.
-        goto entry;
-
-        // Execution continues so long as IP is not zero.
-        // If this is a top-level execution of a pre-defined word, then IP will
-        // remain zero'd and the loop will immediately exit.
-        // If this is a defined word's execution, then its "call" will overwrite
-        // IP (and push the initial zero-IP to the return stack); execution will
-        // continue until we return to the zero-IP.
-        while (IP) {
-            // Retrieve next function pointer list.
-            body = (FuncList)*++IP;
-entry:
-            // Dereference `body` to get the first function in the list.
-            // This is casted to take a FuncList as an argument since defined
-            // words need to know their addresses so that they can perform
-            // their "calls".
-            // If the word is pre-defined then the argument will simply be
-            // ignored.
-            auto func = (void (*)(FuncList))*body;
-            func(body);
-        }
-    }
-
-    return result;
-}
-
-Error execute1(Word *word)
-{
-    // IP must initially be zero if executing a word at the top level.
-    IP = 0;
-    return executor(&word->list);
+    return *rp--;
 }
 
-Word *find(const char *s, int len)
+Word *State::find(const char *s, int len)
 {
-    for (auto w = (Word *)LATEST; w; w = w->link) {
+    for (auto w = latest; w; w = w->link) {
         if (len == (int)strlen(w->name) && strncmp(s, w->name, len) == 0)
             return w;
     }