1 files changed, 129 insertions, 0 deletions
diff --git a/prism/node.h b/prism/node.h
new file mode 100644
index 0000000000..e8686a327c
--- /dev/null
+++ b/prism/node.h
@@ -0,0 +1,129 @@
+/**
+ * @file node.h
+ *
+ * Functions related to nodes in the AST.
+ */
+#ifndef PRISM_NODE_H
+#define PRISM_NODE_H
+
+#include "prism/defines.h"
+#include "prism/parser.h"
+#include "prism/util/pm_buffer.h"
+
+/**
+ * Loop through each node in the node list, writing each node to the given
+ * pm_node_t pointer.
+ */
+#define PM_NODE_LIST_FOREACH(list, index, node) \
+    for (size_t index = 0; index < (list)->size && ((node) = (list)->nodes[index]); index++)
+
+/**
+ * Append a new node onto the end of the node list.
+ *
+ * @param list The list to append to.
+ * @param node The node to append.
+ */
+void pm_node_list_append(pm_node_list_t *list, pm_node_t *node);
+
+/**
+ * Prepend a new node onto the beginning of the node list.
+ *
+ * @param list The list to prepend to.
+ * @param node The node to prepend.
+ */
+void pm_node_list_prepend(pm_node_list_t *list, pm_node_t *node);
+
+/**
+ * Concatenate the given node list onto the end of the other node list.
+ *
+ * @param list The list to concatenate onto.
+ * @param other The list to concatenate.
+ */
+void pm_node_list_concat(pm_node_list_t *list, pm_node_list_t *other);
+
+/**
+ * Free the internal memory associated with the given node list.
+ *
+ * @param list The list to free.
+ */
+void pm_node_list_free(pm_node_list_t *list);
+
+/**
+ * Deallocate a node and all of its children.
+ *
+ * @param parser The parser that owns the node.
+ * @param node The node to deallocate.
+ */
+PRISM_EXPORTED_FUNCTION void pm_node_destroy(pm_parser_t *parser, struct pm_node *node);
+
+/**
+ * Returns a string representation of the given node type.
+ *
+ * @param node_type The node type to convert to a string.
+ * @return A string representation of the given node type.
+ */
+PRISM_EXPORTED_FUNCTION const char * pm_node_type_to_str(pm_node_type_t node_type);
+
+/**
+ * Visit each of the nodes in this subtree using the given visitor callback. The
+ * callback function will be called for each node in the subtree. If it returns
+ * false, then that node's children will not be visited. If it returns true,
+ * then the children will be visited. The data parameter is treated as an opaque
+ * pointer and is passed to the visitor callback for consumers to use as they
+ * see fit.
+ *
+ * As an example:
+ *
+ * ```c
+ * #include "prism.h"
+ *
+ * bool visit(const pm_node_t *node, void *data) {
+ *     size_t *indent = (size_t *) data;
+ *     for (size_t i = 0; i < *indent * 2; i++) putc(' ', stdout);
+ *     printf("%s\n", pm_node_type_to_str(node->type));
+ *
+ *     size_t next_indent = *indent + 1;
+ *     size_t *next_data = &next_indent;
+ *     pm_visit_child_nodes(node, visit, next_data);
+ *
+ *     return false;
+ * }
+ *
+ * int main(void) {
+ *     const char *source = "1 + 2; 3 + 4";
+ *     size_t size = strlen(source);
+ *
+ *     pm_parser_t parser;
+ *     pm_options_t options = { 0 };
+ *     pm_parser_init(&parser, (const uint8_t *) source, size, &options);
+ *
+ *     size_t indent = 0;
+ *     pm_node_t *node = pm_parse(&parser);
+ *
+ *     size_t *data = &indent;
+ *     pm_visit_node(node, visit, data);
+ *
+ *     pm_node_destroy(&parser, node);
+ *     pm_parser_free(&parser);
+ *     return EXIT_SUCCESS;
+ * }
+ * ```
+ *
+ * @param node The root node to start visiting from.
+ * @param visitor The callback to call for each node in the subtree.
+ * @param data An opaque pointer that is passed to the visitor callback.
+ */
+PRISM_EXPORTED_FUNCTION void pm_visit_node(const pm_node_t *node, bool (*visitor)(const pm_node_t *node, void *data), void *data);
+
+/**
+ * Visit the children of the given node with the given callback. This is the
+ * default behavior for walking the tree that is called from pm_visit_node if
+ * the callback returns true.
+ *
+ * @param node The node to visit the children of.
+ * @param visitor The callback to call for each child node.
+ * @param data An opaque pointer that is passed to the visitor callback.
+ */
+PRISM_EXPORTED_FUNCTION void pm_visit_child_nodes(const pm_node_t *node, bool (*visitor)(const pm_node_t *node, void *data), void *data);
+
+#endif