feat: add core types — StringRef, Dialect, StmtType, NodeType enums

Author: renecannao

include/sql_parser/common.h

@@ -0,0 +1,150 @@
+#ifndef SQL_PARSER_COMMON_H
+#define SQL_PARSER_COMMON_H
+
+#include <cstdint>
+#include <cstring>
+#include <type_traits>
+
+namespace sql_parser {
+
+// -- Dialect --
+
+enum class Dialect : uint8_t {
+    MySQL,
+    PostgreSQL
+};
+
+// -- StringRef: zero-copy view into input buffer --
+
+struct StringRef {
+    const char* ptr = nullptr;
+    uint32_t len = 0;
+
+    bool empty() const { return len == 0; }
+
+    bool equals_ci(const char* s, uint32_t slen) const {
+        if (len != slen) return false;
+        for (uint32_t i = 0; i < len; ++i) {
+            char a = ptr[i];
+            char b = s[i];
+            if (a >= 'A' && a <= 'Z') a += 32;
+            if (b >= 'A' && b <= 'Z') b += 32;
+            if (a != b) return false;
+        }
+        return true;
+    }
+
+    bool operator==(const StringRef& o) const {
+        return len == o.len && (ptr == o.ptr || std::memcmp(ptr, o.ptr, len) == 0);
+    }
+    bool operator!=(const StringRef& o) const { return !(*this == o); }
+};
+static_assert(std::is_trivially_copyable_v<StringRef>);
+
+// Case-insensitive comparison for keyword lookup (used by keyword tables)
+inline int ci_cmp(const char* a, uint32_t alen, const char* b, uint8_t blen) {
+    uint32_t minlen = alen < blen ? alen : blen;
+    for (uint32_t i = 0; i < minlen; ++i) {
+        char ca = a[i];
+        char cb = b[i];
+        if (ca >= 'a' && ca <= 'z') ca -= 32;
+        if (cb >= 'a' && cb <= 'z') cb -= 32;
+        if (ca != cb) return ca < cb ? -1 : 1;
+    }
+    if (alen < blen) return -1;
+    if (alen > blen) return 1;
+    return 0;
+}
+
+// -- Statement type (always set, even for PARTIAL/ERROR) --
+
+enum class StmtType : uint8_t {
+    UNKNOWN = 0,
+    SELECT,
+    INSERT,
+    UPDATE,
+    DELETE_STMT,
+    REPLACE,
+    SET,
+    USE,
+    SHOW,
+    BEGIN,
+    START_TRANSACTION,
+    COMMIT,
+    ROLLBACK,
+    SAVEPOINT,
+    PREPARE,
+    EXECUTE,
+    DEALLOCATE,
+    CREATE,
+    ALTER,
+    DROP,
+    TRUNCATE,
+    GRANT,
+    REVOKE,
+    LOCK,
+    UNLOCK,
+    LOAD_DATA,
+    RESET,
+};
+
+// -- AST node types --
+
+enum class NodeType : uint16_t {
+    NODE_UNKNOWN = 0,
+
+    // Tier 2 lightweight nodes
+    NODE_STATEMENT,
+    NODE_TABLE_REF,
+    NODE_SCHEMA_REF,
+    NODE_IDENTIFIER,
+    NODE_QUALIFIED_NAME,
+
+    // Tier 1 nodes (SELECT)
+    NODE_SELECT_STMT,
+    NODE_SELECT_OPTIONS,
+    NODE_SELECT_ITEM_LIST,
+    NODE_SELECT_ITEM,
+    NODE_FROM_CLAUSE,
+    NODE_JOIN_CLAUSE,
+    NODE_WHERE_CLAUSE,
+    NODE_GROUP_BY_CLAUSE,
+    NODE_HAVING_CLAUSE,
+    NODE_ORDER_BY_CLAUSE,
+    NODE_ORDER_BY_ITEM,
+    NODE_LIMIT_CLAUSE,
+    NODE_LOCKING_CLAUSE,
+    NODE_INTO_CLAUSE,
+    NODE_ALIAS,
+
+    // Tier 1 nodes (SET)
+    NODE_SET_STMT,
+    NODE_SET_NAMES,
+    NODE_SET_CHARSET,
+    NODE_SET_TRANSACTION,
+    NODE_VAR_ASSIGNMENT,
+    NODE_VAR_TARGET,
+
+    // Expression nodes
+    NODE_EXPRESSION,
+    NODE_BINARY_OP,
+    NODE_UNARY_OP,
+    NODE_FUNCTION_CALL,
+    NODE_LITERAL_INT,
+    NODE_LITERAL_FLOAT,
+    NODE_LITERAL_STRING,
+    NODE_LITERAL_NULL,
+    NODE_PLACEHOLDER,
+    NODE_SUBQUERY,
+    NODE_COLUMN_REF,
+    NODE_ASTERISK,
+    NODE_IS_NULL,
+    NODE_IS_NOT_NULL,
+    NODE_BETWEEN,
+    NODE_IN_LIST,
+    NODE_CASE_WHEN,
+};
+
+} // namespace sql_parser
+
+#endif // SQL_PARSER_COMMON_H