Change the way expression iteration works

cjdrake · Jun 7, 2015 · b9c2196 · b9c2196
1 parent 47af72c
commit b9c2196
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Showing 5 changed files with 88 additions and 38 deletions.
diff --git a/extension/boolexpr/boolexpr.c b/extension/boolexpr/boolexpr.c
@@ -45,17 +45,21 @@ BoolExprIter_New(struct BoolExpr *ex)
     if (it == NULL)
         return NULL; // LCOV_EXCL_LINE
 
+    it->_ex = ex;
     it->done = false;
-    it->ex = ex;
-
-    if (IS_OP(ex)) {
-        it->index = 0;
-        it->it = BoolExprIter_New(ex->data.xs->items[0]);
-        if (it->it == NULL) {
-            free(it);    // LCOV_EXCL_LINE
-            return NULL; // LCOV_EXCL_LINE
-        }
+
+    if (IS_ATOM(ex)) {
+        it->item = ex;
+        return it;
+    }
+
+    it->_index = 0;
+    it->_it = BoolExprIter_New(ex->data.xs->items[it->_index]);
+    if (it->_it == NULL) {
+        free(it);    // LCOV_EXCL_LINE
+        return NULL; // LCOV_EXCL_LINE
     }
+    it->item = it->_it->item;
 
     return it;
 }
@@ -68,27 +72,47 @@ BoolExprIter_Del(struct BoolExprIter *it)
 }
 
 
-struct BoolExpr *
+bool
 BoolExprIter_Next(struct BoolExprIter *it)
 {
-    if (IS_ATOM(it->ex)) {
+    if (it->done)
+        return true;
+
+    if (IS_ATOM(it->_ex)) {
         it->done = true;
-        return it->ex;
+        return true;
     }
 
-    if (it->it->done) {
-        BoolExprIter_Del(it->it);
-        it->index += 1;
-        if (it->index < it->ex->data.xs->length) {
-            CHECK_NULL(it->it, BoolExprIter_New(it->ex->data.xs->items[it->index]));
-            return BoolExprIter_Next(it->it);
+    if (it->_it) {
+        if (!BoolExprIter_Next(it->_it)) {
+            free(it->_it); // LCOV_EXCL_LINE
+            return false;  // LCOV_EXCL_LINE
         }
 
-        it->done = true;
-        return it->ex;
+        if (!it->_it->done) {
+            it->item = it->_it->item;
+            return true;
+        }
+
+        free(it->_it);
+        it->_index += 1;
+
+        if (it->_index < it->_ex->data.xs->length) {
+            it->_it = BoolExprIter_New(it->_ex->data.xs->items[it->_index]);
+            if (it->_it == NULL)
+                return false; // LCOV_EXCL_LINE
+            it->item = it->_it->item;
+            return true;
+        }
+
+        it->_it = (struct BoolExprIter *) NULL;
+        it->item = it->_ex;
+        return true;
     }
 
-    return BoolExprIter_Next(it->it);
+    it->item = (struct BoolExpr *) NULL;
+    it->done = true;
+    return true;
 }
 
 

diff --git a/extension/boolexpr/boolexpr.h b/extension/boolexpr/boolexpr.h
@@ -147,10 +147,12 @@ struct BoolExpr {
 
 
 struct BoolExprIter {
+    struct BoolExpr *_ex;
+    size_t _index;
+    struct BoolExprIter *_it;
+
+    struct BoolExpr *item;
     bool done;
-    struct BoolExpr *ex;
-    size_t index;
-    struct BoolExprIter *it;
 };
 
 
@@ -396,7 +398,7 @@ struct BoolExprIter * BoolExprIter_New(struct BoolExpr *ex);
 void BoolExprIter_Del(struct BoolExprIter *);
 
 /* Return the next Boolean expression in an iteration. */
-struct BoolExpr * BoolExprIter_Next(struct BoolExprIter *);
+bool BoolExprIter_Next(struct BoolExprIter *);
 
 
 /* Return a new array of Boolean expressions. */

diff --git a/extension/boolexpr/set.c b/extension/boolexpr/set.c
@@ -123,6 +123,7 @@ BoolExprSetIter_Next(struct BoolExprSetIter *it)
         }
     }
 
+    it->item = (struct BoolExprSetItem *) NULL;
     it->done = true;
 }
 

diff --git a/extension/boolexpr/test/test_basic.cpp b/extension/boolexpr/test/test_basic.cpp
@@ -112,9 +112,6 @@ TEST_F(BoolExprTest, DegenerateForms)
 
 TEST_F(BoolExprTest, Iterate)
 {
-    int i;
-    BoolExprIter *it;
-    BoolExpr *ex;
 
     ops[0] = AndN(2, xs[0], xs[1]);
     ops[1] = XorN(2, xs[2], xs[3]);
@@ -123,7 +120,30 @@ TEST_F(BoolExprTest, Iterate)
     ops[4] = ITE(xs[8], xs[9], xs[10]);
     ops[5] = NorN(5, ops[0], ops[1], ops[2], ops[3], ops[4]);
 
-    BoolExpr *expected[] = {
+    size_t count = 0;
+    struct BoolExprIter *it;
+
+    struct BoolExpr *exp0[] = {xs[0]};
+
+    it = BoolExprIter_New(xs[0]);
+    for (count = 0; !it->done; ++count) {
+        EXPECT_EQ(it->item, exp0[0]);
+        BoolExprIter_Next(it);
+    }
+    BoolExprIter_Del(it);
+    EXPECT_EQ(count, 1);
+
+    struct BoolExpr *exp1[] = {xs[0], xs[1], ops[0]};
+
+    it = BoolExprIter_New(ops[0]);
+    for (count = 0; !it->done; ++count) {
+        EXPECT_EQ(it->item, exp1[count]);
+        BoolExprIter_Next(it);
+    }
+    BoolExprIter_Del(it);
+    EXPECT_EQ(count, 3);
+
+    struct BoolExpr *exp2[] = {
         xs[0], xs[1], ops[0],
         xs[2], xs[3], ops[1],
         xs[4], xs[5], ops[2],
@@ -134,13 +154,13 @@ TEST_F(BoolExprTest, Iterate)
     };
 
     it = BoolExprIter_New(ops[5]);
-    for (i = 0; !it->done; ++i) {
-        ex = BoolExprIter_Next(it);
-        EXPECT_EQ(ex, expected[i]);
+    for (count = 0; !it->done; ++count) {
+        EXPECT_EQ(it->item, exp2[count]);
+        BoolExprIter_Next(it);
     }
     BoolExprIter_Del(it);
 
-    EXPECT_EQ(i, 18);
+    EXPECT_EQ(count, 18);
 }
 
 

diff --git a/pyeda/boolalg/exprnodemodule.c b/pyeda/boolalg/exprnodemodule.c
@@ -485,21 +485,24 @@ ExprNode_T = {
 static PyObject *
 ExprNode_next(ExprNode *self)
 {
+    ExprNode *node;
+
     if (self->it->done) {
         BoolExprIter_Del(self->it);
         /* StopIteration */
         return NULL;
     }
 
-    struct BoolExpr *ex = BoolExprIter_Next(self->it);
-    ExprNode *pyex = (ExprNode *) PyObject_CallObject((PyObject *) &ExprNode_T, NULL);
-    if (pyex == NULL) {
+    node = (ExprNode *) PyObject_CallObject((PyObject *) &ExprNode_T, NULL);
+    if (node == NULL) {
         BoolExprIter_Del(self->it);
         return NULL;
     }
-    pyex->ex = BoolExpr_IncRef(ex);
+    node->ex = BoolExpr_IncRef(self->it->item);
 
-    return (PyObject *) pyex;
+    BoolExprIter_Next(self->it);
+
+    return (PyObject *) node;
 }