Changeset 20ac1a4 in mainline for uspace/app/bithenge/expression.c

Timestamp:

2012-07-30T02:07:10Z (12 years ago)

Author:

Sean Bartell <wingedtachikoma@…>

Branches:

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

Children:

78d3a00

Parents:

10334c2e

Message:

Bithenge: add syntactic sugar for if in struct

File:

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

uspace/app/bithenge/expression.c

@@ -420 +420 @@
         bithenge_transform_t base;
         bithenge_expression_t *expr;
+} expression_transform_t;
+
+static inline bithenge_transform_t *expression_as_transform(
+    expression_transform_t *self)
+{
+        return &self->base;
+}
+
+static inline expression_transform_t *transform_as_expression(
+    bithenge_transform_t *base)
+{
+        return (expression_transform_t *)base;
+}
+
+static int expression_transform_apply(bithenge_transform_t *base,
+    bithenge_scope_t *scope, bithenge_node_t *in, bithenge_node_t **out)
+{
+        expression_transform_t *self = transform_as_expression(base);
+        if (bithenge_node_type(in) != BITHENGE_NODE_BLOB)
+                return EINVAL;
+        aoff64_t len;
+        int rc = bithenge_blob_size(bithenge_node_as_blob(in), &len);
+        if (rc != EOK)
+                return rc;
+        if (len != 0)
+                return EINVAL;
+        return bithenge_expression_evaluate(self->expr, scope, out);
+}
+
+static int expression_transform_prefix_length(bithenge_transform_t *base,
+    bithenge_scope_t *scope, bithenge_blob_t *in, aoff64_t *out)
+{
+        *out = 0;
+        return EOK;
+}
+
+static void expression_transform_destroy(bithenge_transform_t *base)
+{
+        expression_transform_t *self = transform_as_expression(base);
+        bithenge_expression_dec_ref(self->expr);
+        free(self);
+}
+
+static const bithenge_transform_ops_t expression_transform_ops = {
+        .apply = expression_transform_apply,
+        .prefix_length = expression_transform_prefix_length,
+        .destroy = expression_transform_destroy,
+};
+
+/** Create a transform that takes an empty blob and produces the result of an
+ * expression. Takes a reference to the expression.
+ * @param[out] out Holds the new transform.
+ * @param expr The expression to evaluate.
+ * @return EOK on success or an error code from errno.h. */
+int bithenge_expression_transform(bithenge_transform_t ** out,
+    bithenge_expression_t *expr)
+{
+        int rc;
+        expression_transform_t *self = malloc(sizeof(*self));
+        if (!self) {
+                rc = ENOMEM;
+                goto error;
+        }
+
+        rc = bithenge_init_transform(expression_as_transform(self),
+            &expression_transform_ops, 0);
+        if (rc != EOK)
+                goto error;
+
+        self->expr = expr;
+        *out = expression_as_transform(self);
+        return EOK;
+
+error:
+        free(self);
+        bithenge_expression_dec_ref(expr);
+        return rc;
+}
+
+typedef struct {
+        bithenge_transform_t base;
+        bithenge_expression_t *expr;
         bithenge_transform_t *true_xform, *false_xform;
 } if_transform_t;