nodestack: turn magic promise numbers into enum + typedef

Document the enum properly, since it's quite unclear what these flags really
mean.

diff --git a/nodestack.cc b/nodestack.cc
index 5c5447595ebb09ee5b58f0e667f5e038e95ead57..2ebfc718a3c89403fb19fff42390d11d284ad789 100644 (file)
--- a/nodestack.cc
+++ b/nodestack.cc
@@ -62,8 +62,8 @@ void Node::print_may_read_from()
  */
 void Node::set_promise(unsigned int i) {
        if (i >= promises.size())
-               promises.resize(i + 1, 0);
-       promises[i] = 1;
+               promises.resize(i + 1, PROMISE_IGNORE);
+       promises[i] = PROMISE_UNFULFILLED;
 }
 
 /**
@@ -72,7 +72,7 @@ void Node::set_promise(unsigned int i) {
  * @return true if the promise should be satisfied by the given model action.
  */
 bool Node::get_promise(unsigned int i) {
-       return (i < promises.size()) && (promises[i] == 2);
+       return (i < promises.size()) && (promises[i] == PROMISE_FULFILLED);
 }
 
 /**
@@ -81,12 +81,12 @@ bool Node::get_promise(unsigned int i) {
  */
 bool Node::increment_promise() {
        for (unsigned int i = 0; i < promises.size(); i++) {
-               if (promises[i] == 1) {
-                       promises[i] = 2;
+               if (promises[i] == PROMISE_UNFULFILLED) {
+                       promises[i] = PROMISE_FULFILLED;
                        while (i > 0) {
                                i--;
-                               if (promises[i] == 2)
-                                       promises[i] = 1;
+                               if (promises[i] == PROMISE_FULFILLED)
+                                       promises[i] = PROMISE_UNFULFILLED;
                        }
                        return true;
                }
@@ -100,7 +100,7 @@ bool Node::increment_promise() {
  */
 bool Node::promise_empty() {
        for (unsigned int i = 0; i < promises.size();i++)
-               if (promises[i] == 1)
+               if (promises[i] == PROMISE_UNFULFILLED)
                        return false;
        return true;
 }

diff --git a/nodestack.h b/nodestack.h
index 68604675cec7363f29864b10c98e5a4788add85c..b440b11d58e3242b359a45be8fdac52267c99726 100644 (file)
--- a/nodestack.h
+++ b/nodestack.h
@@ -13,6 +13,19 @@
 
 class ModelAction;
 
+/**
+ * A flag used for the promise counting/combination problem within a node,
+ * denoting whether a particular Promise is
+ * <ol><li>@b applicable: can be satisfied by this Node's ModelAction and</li>
+ * <li>@b fulfilled: satisfied by this Node's ModelAction under the current
+ * configuration.</li></ol>
+ */
+typedef enum {
+       PROMISE_IGNORE = 0, /**< This promise is inapplicable; ignore it */
+       PROMISE_UNFULFILLED, /**< This promise is applicable but unfulfilled */
+       PROMISE_FULFILLED /**< This promise is applicable and fulfilled */
+} promise_t;
+
 /**
  * @brief A single node in a NodeStack
  *
@@ -78,7 +91,7 @@ private:
        unsigned int read_from_index;
 
        std::vector< uint64_t, MyAlloc< uint64_t > > future_values;
-       std::vector< unsigned int, MyAlloc<unsigned int> > promises;
+       std::vector< promise_t, MyAlloc<promise_t> > promises;
        unsigned int future_index;
 };