Changeset 78d3a00 in mainline for uspace/app/bithenge/expression.c

Timestamp:

2012-07-31T21:07:26Z (13 years ago)

Author:

Sean Bartell <wingedtachikoma@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

3f2ea63

Parents:

20ac1a4

Message:

Bithenge: add switch transforms and sugar

File:

• uspace/app/bithenge/expression.c (modified) (1 diff)

uspace/app/bithenge/expression.c

@@ -63 +63 @@
 }
 
+typedef struct {
+        bithenge_expression_t base;
+        bithenge_binary_op_t op;
+        bithenge_expression_t *a, *b;
+} binary_expression_t;
+
+static inline binary_expression_t *expression_as_binary(
+    bithenge_expression_t *base)
+{
+        return (binary_expression_t *)base;
+}
+
+static inline bithenge_expression_t *binary_as_expression(
+    binary_expression_t *self)
+{
+        return &self->base;
+}
+
+static int binary_expression_evaluate(bithenge_expression_t *base,
+    bithenge_scope_t *scope, bithenge_node_t **out)
+{
+        binary_expression_t *self = expression_as_binary(base);
+        bithenge_node_t *a, *b;
+        int rc = bithenge_expression_evaluate(self->a, scope, &a);
+        if (rc != EOK)
+                return rc;
+        rc = bithenge_expression_evaluate(self->b, scope, &b);
+        if (rc != EOK) {
+                bithenge_node_dec_ref(a);
+                return rc;
+        }
+        switch (self->op) {
+        case BITHENGE_EXPRESSION_EQUALS:
+                rc = bithenge_new_boolean_node(out, bithenge_node_equal(a, b));
+                break;
+        }
+        bithenge_node_dec_ref(a);
+        bithenge_node_dec_ref(b);
+        return rc;
+}
+
+static void binary_expression_destroy(bithenge_expression_t *base)
+{
+        binary_expression_t *self = expression_as_binary(base);
+        bithenge_expression_dec_ref(self->a);
+        bithenge_expression_dec_ref(self->b);
+        free(self);
+}
+
+static const bithenge_expression_ops_t binary_expression_ops = {
+        .evaluate = binary_expression_evaluate,
+        .destroy = binary_expression_destroy,
+};
+
+/** Create a binary expression. Takes ownership of @a a and @a b.
+ * @param[out] out Holds the new expression.
+ * @param op The operator to apply.
+ * @param a The first operand.
+ * @param b The second operand.
+ * @return EOK on success or an error code from errno.h. */
+int bithenge_binary_expression(bithenge_expression_t **out,
+    bithenge_binary_op_t op, bithenge_expression_t *a,
+    bithenge_expression_t *b)
+{
+        int rc;
+        binary_expression_t *self = malloc(sizeof(*self));
+        if (!self) {
+                rc = ENOMEM;
+                goto error;
+        }
+
+        rc = bithenge_init_expression(binary_as_expression(self),
+            &binary_expression_ops);
+        if (rc != EOK)
+                goto error;
+
+        self->op = op;
+        self->a = a;
+        self->b = b;
+        *out = binary_as_expression(self);
+        return EOK;
+
+error:
+        bithenge_expression_dec_ref(a);
+        bithenge_expression_dec_ref(b);
+        free(self);
+        return rc;
+}
+
 static int current_node_evaluate(bithenge_expression_t *self,
     bithenge_scope_t *scope, bithenge_node_t **out)