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diff --git a/src/libknot/yparser/yparser.h b/src/libknot/yparser/yparser.h
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+/*  Copyright (C) 2022 CZ.NIC, z.s.p.o. <knot-dns@labs.nic.cz>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+/*!
+ * \file
+ *
+ * \brief Simple parser (Yparser) of a YAML-inspired data format.
+ *
+ * \addtogroup yparser
+ * @{
+ */
+
+#pragma once
+
+#include <stdbool.h>
+#include <stddef.h>
+
+/*! Maximal length of textual key value. */
+#define YP_MAX_TXT_KEY_LEN	127
+/*! Maximal length of textual data value. */
+#define YP_MAX_TXT_DATA_LEN	32767
+
+/*! Parser events indicating type of lastly parsed item. */
+typedef enum {
+	YP_ENULL = 0, /*!< No valid data. */
+	YP_EKEY0,     /*!< First level item. */
+	YP_EKEY1,     /*!< Second level item. */
+	YP_EID,       /*!< Second level identifier. */
+} yp_event_t;
+
+/*! Context structure of yparser. */
+typedef struct {
+	/*! Current parser state (Ragel internals). */
+	int cs;
+	/*! Indication if the current item was already processed. */
+	bool processed;
+	/*! Current block indentation. */
+	size_t indent;
+	/*! Last id dash position. */
+	size_t id_pos;
+
+	/*! Input parameters. */
+	struct {
+		/*! Start of the block. */
+		const char *start;
+		/*! Current parser position. */
+		const char *current;
+		/*! End of the block. */
+		const char *end;
+		/*! Indication for the final block parsing. */
+		bool eof;
+	} input;
+
+	/*! File input parameters. */
+	struct {
+		/*! File name. */
+		char *name;
+		/*! File descriptor. */
+		int descriptor;
+	} file;
+
+	/*! [out] Current line number (error location). */
+	size_t line_count;
+	/*! [out] Current event. */
+	yp_event_t event;
+	/*! [out] Parsed key (zero terminated string). */
+	char key[YP_MAX_TXT_KEY_LEN + 1];
+	/*! [out] Key length. */
+	size_t key_len;
+	/*! [out] Parsed data (zero terminated string). */
+	char data[YP_MAX_TXT_DATA_LEN + 1];
+	/*! [out] Data length. */
+	size_t data_len;
+} yp_parser_t;
+
+/*!
+ * Initializes the parser.
+ *
+ * \param[in] parser Parser context.
+ */
+void yp_init(
+	yp_parser_t *parser
+);
+
+/*!
+ * Deinitializes the parser.
+ *
+ * \param[in] parser Parser context.
+ */
+void yp_deinit(
+	yp_parser_t *parser
+);
+
+/*!
+ * Sets the parser to parse given string.
+ *
+ * \param[in] parser Parser context.
+ * \param[in] input The string to parse.
+ * \param[in] size Length of the string.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int yp_set_input_string(
+	yp_parser_t *parser,
+	const char *input,
+	size_t size
+);
+
+/*!
+ * Sets the parser to parse given file.
+ *
+ * \param[in] parser Parser context.
+ * \param[in] file_name The filename to parse.
+ *
+ * \return Error code, KNOT_EOK if success.
+ */
+int yp_set_input_file(
+	yp_parser_t *parser,
+	const char *file_name
+);
+
+/*!
+ * Parses one item from the input.
+ *
+ * If the item has more values, this function returns for each value. The item
+ * can also have no value.
+ *
+ * \param[in] parser Parser context.
+ *
+ * \return Error code, KNOT_EOK if success, KNOT_EOF if end of data.
+ */
+int yp_parse(
+	yp_parser_t *parser
+);
+
+/*! @} */