goments

1 files changed, 52 insertions, 31 deletions

diff --git a/calc/main.c b/calc/main.c
index 0910967..f21905d 100644
--- a/calc/main.c
+++ b/calc/main.c
@@ -80,22 +80,25 @@ static void op_normal(char c){
   switch(c){
     wbool_t p;
 
+    ////////////////////////////////////////////////////////////////
     //stickies
-  case '(': 
+    ////////////////////////////////////////////////////////////////
+
+  case '(': //enter comment
     comm_lev = 1;
     break;
 
-  case ')': 
+  case ')': //exit comment (but we are not in one)
     e("mismatched close-comment parenthesis!");
 
-  case '[': 
+  case '[': //enter quote
     quote_lev = 1;
     break;
 
-  case ']': 
+  case ']': //exit quote (but we are not in one)
     e("mismatched close-quote bracket!");
 
-  case '{': 
+  case '{': //enter taken conditional branch
     want(1);
     if(fz_zero(&STACK(sp),fl)){
       cond_lev = 1;
@@ -103,100 +106,115 @@ static void op_normal(char c){
     drop();
     break;
 
-  case '}': 
+  case '}': //exit non-taken conditional branch
     push();
     fz_frombool(&STACK(sp),fl,0);
     break;
 
+    ////////////////////////////////////////////////////////////////
     //stack motion
-  case '.': 
+    ////////////////////////////////////////////////////////////////
+
+  case '.': //push 0 onto stack
     push();
     fz_clear(&STACK(sp),fl);
     break;
 
-  case '"': 
+  case '"': //duplicate top item
     want(1);
     push();
     fz_copy(&STACK(sp-1),&STACK(sp),fl);
     break;
 
-  case '_': 
+  case '_': //drop top item
     want(1);
     drop();
     break;
 
-  case '\'': 
+  case '\'': //swap 2 top items
     want(2);
     fz_swap(&STACK(sp),&STACK(sp-1),fl);
     break;
 
-  case '`': 
+  case '`': //push copy of sp-1 to stack (over)
     want(2);
     push();
     fz_copy(&STACK(sp-2),&STACK(sp),fl);
     break;
 
+    ////////////////////////////////////////////////////////////////
     //predicates
-  case '=': 
+    ////////////////////////////////////////////////////////////////
+
+  case '=': //equality
     want(2);
     p = fz_eq(&STACK(sp-1),&STACK(sp),fl);
     drop();
     fz_frombool(&STACK(sp),fl,p);
     break;
 
-  case '<': 
+  case '<': //less than
     want(2);
     p = fz_lt(&STACK(sp-1),&STACK(sp),fl);
     drop();
     fz_frombool(&STACK(sp),fl,p);
     break;
 
-  case '>': 
+  case '>': //greater than
     want(2);
     p = fz_gt(&STACK(sp-1),&STACK(sp),fl);
     drop();
     fz_frombool(&STACK(sp),fl,p);
     break;
 
-    //arithmetic
-  case '+': 
+    ////////////////////////////////////////////////////////////////
+    //arithmetic ops
+    ////////////////////////////////////////////////////////////////
+
+  case '+': //add
     want(2);
     flag = fz_add(&STACK(sp-1),&STACK(sp),&STACK(sp-1),fl);
     drop();
     break;
 
-  case '-': 
+  case '-': //subtract
     want(2);
     flag = fz_sub(&STACK(sp-1),&STACK(sp),&STACK(sp-1),fl);
     drop();
     break;
 
-    //bitwise
-  case '&': 
+    ////////////////////////////////////////////////////////////////
+    //bitwise ops
+    ////////////////////////////////////////////////////////////////
+
+  case '&': //bitwise and
     want(2);
     fz_and(&STACK(sp-1),&STACK(sp),&STACK(sp-1),fl);
     drop();
     break;
 
-  case '|': 
+  case '|': //bitwise or
     want(2);
     fz_or(&STACK(sp-1),&STACK(sp),&STACK(sp-1),fl);
     drop();
     break;
 
-  case '^': 
+  case '^': //bitwise xor
     want(2);
     fz_xor(&STACK(sp-1),&STACK(sp),&STACK(sp-1),fl);
     drop();
     break;
 
-  case '~': 
+  case '~': //bitwise not
     want(1);
     fz_not(&STACK(sp),&STACK(sp),fl);
     break;
 
+    ////////////////////////////////////////////////////////////////
     //other
-  case 'U': 
+    ////////////////////////////////////////////////////////////////
+
+  case 'U': //mUx
     want(3);
     wbool_t sel = fz_nzero(&STACK(sp),fl);
     fz_mux(&STACK(sp-2),&STACK(sp-1),&STACK(sp-2),fl,sel);
@@ -204,31 +222,34 @@ static void op_normal(char c){
     drop();
     break;
 
-  case 'O': 
+  case 'O': //push carry/borrow flag to stack
     push();
     fz_frombool(&STACK(sp),fl,flag);
     break;
 
-  case '#': 
+  case '#': //print top item and drop it
     want(1);
-    dump_fz(&STACK(p),fl);
+    dump_fz(&STACK(sp),fl);
     drop();
     break;
 
-  case 'Z': 
+  case 'Z': //zap the stack
     zap();
     break;
 
-  case 'Q': 
+  case 'Q': //quit with stack trace
     for(size_t x = sp;x != STACK_INIT;x--){
-      dump_fz(&STACK(p),fl);
+      dump_fz(&STACK(x),fl);
     }
     exit(0);
     break;
 
-  default:
+    ////////////////////////////////////////////////////////////////
     //immediates
-    if(char_isnib(c)){
+    ////////////////////////////////////////////////////////////////
+
+  default:
+    if(char_isnib(c)){ //shift nibble into top item
       want(1);
       ins_nib(&STACK(sp),char_getnib(c));  
     }