/* Copyright 2005 Garrett Rooney.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#ifndef LEXER_H
#define LEXER_H

#include <apr_pools.h>
#include <apr_buckets.h>

#include "parser.h"

/* A lexer for the ETL language. */
typedef struct etl_lexer_t etl_lexer_t;

#define ETL_TOK_EOI 47 /* sufficiently big... */

typedef int etl_token_t;

/* Return a lexer that will scan the contents of BB, allocated in POOL. */
etl_lexer_t *etl_lexer_create (apr_bucket_brigade *bb, apr_pool_t *pool);

/* Scan forward to find the next token in LEXER, returning it in *TOK, using
 * POOL for temporary allocations. */
apr_status_t
etl_lexer_scan (etl_token_t *tok,
                etl_lexer_t *lexer,
                apr_pool_t *pool);

/* Get the text for the last token returned by LEXER, allocated in POOL.
 *
 * Note: This is really only meaningful if the last token was ETL_TOK_TEXT,
 *       in all other situations it will return NULL. */
char *
etl_lexer_text (etl_lexer_t *lexer, apr_pool_t *pool);

#endif /* LEXER_H */