+ * When the input matches the grammar tree, the string vector associated
+ * to the root node of the returned parsing tree is the same than the
+ * strvec argument. Calling ec_pnode_matches() on this tree returns true.
+ *
+ * If the input does not match the grammar tree, the returned parsing
+ * tree only contains one root node, with no associated string vector.
+ * Calling ec_pnode_matches() on this tree returns false.
+ *
+ * @param node
+ * The grammar node.
+ * @param str
+ * The input string vector.
+ * @return
+ * A parsing tree, or NULL on error (errno is set).