duskos

commit 776bd6c3605cb3d645a5a1def2c597ec5baf963a
parent f2be4ec972f3c4c4ef87440f9f7456af117b1a53
Author: Virgil Dupras <hsoft@hardcoded.net>
Date:   Wed,  1 Jun 2022 13:51:40 -0400

Add to

Diffstat:
M
asm.py
 | 
16
+++++++++++++++-
M
dusk.c
 | 
9
+++++++--
M
forth.txt
 | 
9
++++++---
M
ops.txt
 | 
2
+-

4 files changed, 29 insertions(+), 7 deletions(-)
diff --git a/asm.py b/asm.py
@@ -81,13 +81,20 @@ def exitwr():
     opwr('exit')
 
 def _if_():
-    opwr('_br_')
+    opwr('_cbr_')
     ps.append(pc())
     intwr(0)
 
 def _then_():
     intset(ps.pop(), pc())
 
+def _else_():
+    x = ps.pop()
+    opwr('_br_')
+    ps.append(pc())
+    intwr(0)
+    intset(x, pc())
+
 def _begin_():
     ps.append(pc())
 
@@ -120,6 +127,11 @@ def slitwr():
     litwr(spc)
     litwr(len(s))
 
+def _create_():
+    newword()
+    opwr('_call_')
+    intwr(labels[b'lblcell'])
+
 def _value_():
     newword()
     opwr('_call_')
@@ -133,10 +145,12 @@ special = {
     b'S"': slitwr,
     b'if': _if_,
     b'then': _then_,
+    b'else': _else_,
     b'begin': _begin_,
     b'again': _again_,
     b'until': _until_,
     b'next': _next_,
+    b'create': _create_,
     b'value': _value_,
 }
 
diff --git a/dusk.c b/dusk.c
@@ -26,6 +26,7 @@ byte mem[MEMSIZE];
 struct stack ps, rs;
 cell pc;
 byte running;
+byte toflag;
 
 /* Utilities */
 static cell gc(cell addr) {
@@ -67,7 +68,11 @@ static void bye() { running = 0; }
 
 /* memory */
 static void cfetch() { cell a = pop(); push(mem[a]); }
+static void cstore() { cell a = pop(); mem[a] = pop(); }
 static void fetch() { cell a = pop(); push(gc(a)); }
+static void store() { cell a = pop(); sc(a, pop()); }
+static void to() { toflag = 1; }
+static void isto() { push(toflag); toflag = 0; }
 
 /* arithmetic */
 static void inc() { push(pop()+1); }
@@ -81,7 +86,7 @@ static void add() { cell a = pop(); cell b = pop(); push(a+b); }
 static void emit() { putchar(pop()); }
 static void key() { push(getchar()); }
 
-static void (*ops[22])() = {
+static void (*ops[26])() = {
 #include "ops.txt"
 };
 
@@ -116,7 +121,7 @@ int main() {
         c = getc(fp);
     }
     fclose(fp);
-    ps.ptr = rs.ptr = pc = 0;
+    ps.ptr = rs.ptr = pc = toflag = 0;
     running = 1;
     while (step());
     return 0;
diff --git a/forth.txt b/forth.txt
@@ -1,6 +1,9 @@
 _br_ lblboot
-lblval: r2p fetch ;
-value hello
+lblcell: r2p ;
+lblval: r2p isto if store else fetch then ;
+create in(
+," xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+value in>
 : c@+ dup inc swap cfetch ;
 : << shl drop ;
 : >> shr drop ;
@@ -9,4 +12,4 @@ lblhex: ," 0123456789abcdef"
 : .x dup >> >> >> >> .h .h ;
 : stype p2r begin c@+ emit next ;
 : foo S" Dusk OS" stype ;
-: BOOT lblboot: foo hello .x bye
+: BOOT lblboot: foo 42 to in> in> .x bye
diff --git a/ops.txt b/ops.txt
@@ -1,5 +1,5 @@
 _i_, drop, dup, swap, p2r, r2p,
 _br_, _cbr_, _next_, _call_, exit, bye,
-cfetch, fetch,
+cfetch, cstore, fetch, store, to, isto,
 inc, dec, shl, shr, and, add,
 emit, key