Changeset f85ca3f in mainline

Timestamp:

2012-07-28T21:25:49Z (12 years ago)

Author:

Sean Bartell <wingedtachikoma@…>

Branches:

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

Children:

84e8a70

Parents:

32eb01b

Message:

Bithenge: add expressions that use the current node being created

Location:

uspace/app/bithenge

Files:

• expression.c (modified) (2 diffs)
• expression.h (modified) (1 diff)
• script.c (modified) (4 diffs)
• transform.c (modified) (1 diff)
• transform.h (modified) (4 diffs)

uspace/app/bithenge/expression.c

@@ -58 +58 @@
 }
 
+static void expression_indestructible(bithenge_expression_t *self)
+{
+        assert(false);
+}
+
+static int current_node_evaluate(bithenge_expression_t *self,
+    bithenge_scope_t *scope, bithenge_node_t **out)
+{
+        *out = bithenge_scope_get_current_node(scope);
+        if (!*out)
+                return EINVAL;
+        return EOK;
+}
+
+static const bithenge_expression_ops_t current_node_ops = {
+        .evaluate = current_node_evaluate,
+        .destroy = expression_indestructible,
+};
+
+static bithenge_expression_t current_node_expression = {
+        &current_node_ops, 1
+};
+
+/** Create an expression that gets the current node being created.
+ * @param[out] out Holds the new expression.
+ * @return EOK on success or an error code from errno.h. */
+int bithenge_current_node_expression(bithenge_expression_t **out)
+{
+        bithenge_expression_inc_ref(&current_node_expression);
+        *out = &current_node_expression;
+        return EOK;
+}
+
 typedef struct {
         bithenge_expression_t base;
@@ -176 +209 @@
         *out = const_as_expression(self);
         return EOK;
+}
+
+typedef struct {
+        bithenge_expression_t base;
+        bithenge_expression_t *expr;
+        bithenge_node_t *key;
+} member_expression_t;
+
+static member_expression_t *expression_as_member(bithenge_expression_t *base)
+{
+        return (member_expression_t *)base;
+}
+
+static bithenge_expression_t *member_as_expression(member_expression_t *expr)
+{
+        return &expr->base;
+}
+
+static int member_expression_evaluate(bithenge_expression_t *base, 
+    bithenge_scope_t *scope, bithenge_node_t **out)
+{
+        member_expression_t *self = expression_as_member(base);
+        bithenge_node_t *node;
+        int rc = bithenge_expression_evaluate(self->expr, scope, &node);
+        if (rc != EOK)
+                return rc;
+        bithenge_node_inc_ref(self->key);
+        rc = bithenge_node_get(node, self->key, out);
+        bithenge_node_dec_ref(node);
+        return rc;
+}
+
+static void member_expression_destroy(bithenge_expression_t *base)
+{
+        member_expression_t *self = expression_as_member(base);
+        bithenge_expression_dec_ref(self->expr);
+        bithenge_node_dec_ref(self->key);
+        free(self);
+}
+
+static const bithenge_expression_ops_t member_expression_ops = {
+        .evaluate = member_expression_evaluate,
+        .destroy = member_expression_destroy,
+};
+
+/** Create an expression that gets a member from a node. Takes references to
+ * @a expr and @a key.
+ * @param[out] out Holds the new expression.
+ * @param expr Calculates the node to get the member of.
+ * @param key The member to get.
+ * @return EOK on success or an error code from errno.h. */
+int bithenge_member_expression(bithenge_expression_t **out,
+    bithenge_expression_t *expr, bithenge_node_t *key)
+{
+        int rc;
+        member_expression_t *self = malloc(sizeof(*self));
+        if (!self) {
+                rc = ENOMEM;
+                goto error;
+        }
+
+        rc = bithenge_init_expression(member_as_expression(self),
+            &member_expression_ops);
+        if (rc != EOK)
+                goto error;
+
+        self->expr = expr;
+        self->key = key;
+        *out = member_as_expression(self);
+        return EOK;
+
+error:
+        bithenge_expression_dec_ref(expr);
+        bithenge_node_dec_ref(key);
+        free(self);
+        return rc;
 }
 

uspace/app/bithenge/expression.h

@@ -93 +93 @@
 int bithenge_init_expression(bithenge_expression_t *,
     const bithenge_expression_ops_t *);
+int bithenge_current_node_expression(bithenge_expression_t **);
 int bithenge_param_expression(bithenge_expression_t **, int);
 int bithenge_const_expression(bithenge_expression_t **, bithenge_node_t *);
+int bithenge_member_expression(bithenge_expression_t **,
+    bithenge_expression_t *, bithenge_node_t *);
 int bithenge_param_wrapper(bithenge_transform_t **, bithenge_transform_t *,
     bithenge_expression_t **);

uspace/app/bithenge/script.c

@@ -119 +119 @@
 }
 
-/** Note that an error has occurred. */
+/** Note that an error has occurred if error is not EOK. */
 static void error_errno(state_t *state, int error)
 {
         // Don't overwrite a previous error.
-        if (state->error == EOK) {
+        if (state->error == EOK && error != EOK) {
                 done_with_token(state);
                 state->token = TOKEN_ERROR;
@@ -220 +220 @@
                 int rc = bithenge_parse_int(state->buffer +
                     state->old_buffer_pos, &state->token_int);
-                if (rc != EOK)
-                        error_errno(state, rc);
+                error_errno(state, rc);
         } else if (ch == '<') {
                 state->token = ch;
@@ -368 +367 @@
 
                 next_token(state);
+
+                return expr;
+        } else if (state->token == '.') {
+                next_token(state);
+
+                const char *id = expect_identifier(state);
+                bithenge_node_t *key = NULL;
+                bithenge_expression_t *expr = NULL;
+                int rc = bithenge_current_node_expression(&expr);
+                error_errno(state, rc);
+
+                if (state->error == EOK) {
+                        rc = bithenge_new_string_node(&key, id, true);
+                        id = NULL;
+                        error_errno(state, rc);
+                }
+
+                if (state->error == EOK) {
+                        rc = bithenge_member_expression(&expr, expr, key);
+                        key = NULL;
+                        if (rc != EOK)
+                                expr = NULL;
+                        error_errno(state, rc);
+                }
+
+                if (state->error != EOK) {
+                        free((char *)id);
+                        bithenge_node_dec_ref(key);
+                        bithenge_expression_dec_ref(expr);
+                        return NULL;
+                }
 
                 return expr;
@@ -588 +618 @@
         done_with_token(state);
         state->token = TOKEN_ERROR;
-        fclose(state->file);
+        if (state->file)
+                fclose(state->file);
         transform_list_t *entry = state->transform_list;
         while (entry) {

uspace/app/bithenge/transform.c

@@ -552 +552 @@
         node->blob = bithenge_node_as_blob(in);
         *out = struct_as_node(node);
+        bithenge_node_inc_ref(*out);
+        bithenge_scope_set_current_node(&node->scope, *out);
         return EOK;
 }

uspace/app/bithenge/transform.h

@@ -52 +52 @@
 typedef struct {
         /** @privatesection */
+        int num_params;
         bithenge_node_t **params;
-        int num_params;
+        bithenge_node_t *current_node;
 } bithenge_scope_t;
 
@@ -74 +75 @@
 static inline void bithenge_scope_init(bithenge_scope_t *scope)
 {
+        scope->num_params = 0;
         scope->params = NULL;
-        scope->num_params = 0;
+        scope->current_node = NULL;
 }
 
@@ -83 +85 @@
 static inline void bithenge_scope_destroy(bithenge_scope_t *scope)
 {
+        bithenge_node_dec_ref(scope->current_node);
         for (int i = 0; i < scope->num_params; i++)
                 bithenge_node_dec_ref(scope->params[i]);
@@ -104 +107 @@
         for (int i = 0; i < out->num_params; i++)
                 bithenge_node_inc_ref(out->params[i]);
-        return EOK;
+        out->current_node = scope->current_node;
+        if (out->current_node)
+                bithenge_node_inc_ref(out->current_node);
+        return EOK;
+}
+
+/** Set the current node being created. Takes a reference to @a node.
+ * @param scope The scope to set the current node in.
+ * @param node The current node being created.
+ * @return EOK on success or an error code from errno.h. */
+static inline void bithenge_scope_set_current_node(bithenge_scope_t *scope,
+    bithenge_node_t *node)
+{
+        bithenge_node_dec_ref(scope->current_node);
+        scope->current_node = node;
+}
+
+/** Get the current node being created, which may be NULL.
+ * @param scope The scope to get the current node from.
+ * @return The node being created, or NULL. */
+static inline bithenge_node_t *bithenge_scope_get_current_node(
+    bithenge_scope_t *scope)
+{
+        if (scope->current_node)
+                bithenge_node_inc_ref(scope->current_node);
+        return scope->current_node;
 }
 
 /** Allocate parameters. The parameters must then be set with @a
- * bithenge_scope_set_param.
+ * bithenge_scope_set_param. This must not be called on a scope that already
+ * has parameters.
  * @param scope The scope in which to allocate parameters.
  * @param num_params The number of parameters to allocate.