text: /*
   * Copyright 2019 The Hafnium Authors.
   *
   * 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
   *
   *     https://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.
   */
  
  //#pragma once
  #ifdef HF_STRING_H
  #else
  #define HF_STRING_H
  
  #include <stdbool.h>
  #include <stddef.h>
  
  /**
   * Maximum length of a string including the NULL terminator.
   * This is an arbitrary number and can be adjusted to fit use cases.
   */
  #define STRING_MAX_SIZE 32
  
  typedef enum string_return_code {
  	STRING_SUCCESS,
  	STRING_ERROR_INVALID_INPUT,
  	STRING_ERROR_TOO_LONG
  } string_return_code;
  
  /**
   * Statically-allocated string data structure with input validation to ensure
   * strings are properly NULL-terminated.
   *
   * This is intentionally kept as simple as possible and should not be extended
   * to perform complex string operations without a good use case.
   */
  struct string {
  	char data[STRING_MAX_SIZE];
  };
  
  /**
   * Macro to initialize `struct string` from a string constant.
   * Triggers a compilation error if the string does not fit into the buffer.
   */
  #define STRING_INIT(str) ((struct string){.data = str})
  
  string_return_code string_init(struct string *str, const char *data,
  				    size_t size);
  void string_init_empty(struct string *str);
  bool string_is_empty(const struct string *str);
  const char *string_data(const struct string *str);
  
  #endif
  