Changes in doc/papers/concurrency/examples/Fib.cfa [b60ed54:600d7be]

File:

• doc/papers/concurrency/examples/Fib.cfa (modified) (2 diffs)

doc/papers/concurrency/examples/Fib.cfa

@@ -13 +13 @@
 }
 
-#define FibCtor { 1, 0 }
-typedef struct { int fn1, fn; } Fib;
-int fib_state( Fib & f ) with(f) {
-        int ret = fn; fn = fn1; fn1 = fn + ret;
-        return ret;
+#define FibCtor { 0, 1 }
+typedef struct { int fn, fn1; } Fib;
+int fib_state( Fib & f ) with( f ) {
+        int fn0 = fn1 + fn2;  fn2 = fn1;  fn = fn0;
+        return fn1;
 }
 
@@ -32 +32 @@
 coroutine Fib2 { int fn; };                                             // used for communication
 void main( Fib2 & fib ) with( fib ) {                   // called on first resume
-        int fn1;                                                                        // precompute first two states
-        [fn1, fn] = [1, 0];
+        int fn1 = 1, fn2 = 0;                                           // precompute first two states
         for () {
+                fn = fn1 + fn2;  fn2 = fn1;  fn1 = fn;  // general case
                 suspend();                                                              // restart last resume
-                [fn1, fn] = [fn, fn + fn1];
         }
 }
-int ?()( Fib2 & fib ) {                                                 // function-call interface
+int ?()( Fib2 & fib ) with( fib ) {
         return resume( fib ).fn;                                        // restart last suspend
 }
-int ?()( Fib2 & fib, int N ) {                                  // skip N values
-        for ( N - 1 ) fib();                                            // use function-call interface
+int ?()( Fib2 & fib, int N ) with( fib ) {
+        for ( N - 1 ) fib();
         return fib();
 }
-double ?()( Fib2 & fib ) {                                              // different return type
-        return (int)(fib()) / 3.14159;                          // cast prevents recursive call
+double ?()( Fib2 & fib ) with( fib ) {
+        return (int)(fib()) / 3.14159;                                          // restart last suspend
 }