feat: add AstNode (32-byte) and ParseResult structs

Author: renecannao

include/sql_parser/ast.h

@@ -0,0 +1,53 @@
+#ifndef SQL_PARSER_AST_H
+#define SQL_PARSER_AST_H
+
+#include "sql_parser/common.h"
+#include "sql_parser/arena.h"
+#include <cstdint>
+#include <type_traits>
+
+namespace sql_parser {
+
+struct AstNode {
+    AstNode* first_child;
+    AstNode* next_sibling;
+    const char* value_ptr;
+    uint32_t value_len;
+    NodeType type;
+    uint16_t flags;
+
+    StringRef value() const { return StringRef{value_ptr, value_len}; }
+
+    void set_value(StringRef ref) {
+        value_ptr = ref.ptr;
+        value_len = ref.len;
+    }
+
+    void add_child(AstNode* child) {
+        if (!child) return;
+        if (!first_child) {
+            first_child = child;
+            return;
+        }
+        AstNode* last = first_child;
+        while (last->next_sibling) last = last->next_sibling;
+        last->next_sibling = child;
+    }
+};
+static_assert(sizeof(AstNode) == 32, "AstNode must be 32 bytes");
+static_assert(std::is_trivially_copyable_v<AstNode>);
+
+inline AstNode* make_node(Arena& arena, NodeType type, StringRef value = {},
+                          uint16_t flags = 0) {
+    AstNode* node = arena.allocate_typed<AstNode>();
+    if (!node) return nullptr;
+    node->type = type;
+    node->flags = flags;
+    node->value_ptr = value.ptr;
+    node->value_len = value.len;
+    return node;
+}
+
+} // namespace sql_parser
+
+#endif // SQL_PARSER_AST_H

include/sql_parser/parse_result.h

@@ -0,0 +1,33 @@
+#ifndef SQL_PARSER_PARSE_RESULT_H
+#define SQL_PARSER_PARSE_RESULT_H
+
+#include "sql_parser/common.h"
+#include "sql_parser/ast.h"
+
+namespace sql_parser {
+
+struct ErrorInfo {
+    uint32_t offset = 0;
+    StringRef message;
+};
+
+struct ParseResult {
+    enum Status : uint8_t { OK = 0, PARTIAL, ERROR };
+
+    Status status = ERROR;
+    StmtType stmt_type = StmtType::UNKNOWN;
+    AstNode* ast = nullptr;
+    ErrorInfo error;
+    StringRef remaining;
+
+    StringRef table_name;
+    StringRef schema_name;
+    StringRef database_name;
+
+    bool ok() const { return status == OK; }
+    bool has_remaining() const { return !remaining.empty(); }
+};
+
+} // namespace sql_parser
+
+#endif // SQL_PARSER_PARSE_RESULT_H