code / tomo

   1 // This file defines some functions to make it easy to parse simply formatted
   2 // strings **correctly** without memory bugs.
   3 //
   4 //     strparse(input_str, format...) - parse a string
   5 //
   6 // Examples:
   7 //
   8 //     const char *filename; long line_num;
   9 //     const char *err = NULL;
  10 //     if ((err=strparse("foo.c:12", &filename, ":", &line_num)))
  11 //         errx(1, "Failed to parse file:line at: ", err);
  12 //
  13 //     const char *item1, *item2;
  14 //     if ((err=strparse("one, two", &item1, ",", PARSE_WHITESPACE, &item2)))
  15 //         errx(1, "Failed to parse items at: ", err);
  16 
  17 #pragma once
  18 
  19 #include <stdbool.h>
  20 #include <stdint.h>
  21 #include <stdio.h>
  22 
  23 #include "mapmacro.h"
  24 
  25 typedef struct {
  26     char c;
  27 } some_char_t;
  28 #define PARSE_SOME_OF(chars) ((some_char_t *)chars)
  29 #define PARSE_WHITESPACE PARSE_SOME_OF(" \t\r\n\v")
  30 typedef enum { PARSE_LITERAL, PARSE_LONG, PARSE_DOUBLE, PARSE_BOOL, PARSE_STRING, PARSE_SOME_OF } parse_type_e;
  31 
  32 typedef struct {
  33     parse_type_e type;
  34     void *dest;
  35 } parse_element_t;
  36 
  37 #define _parse_type(dest)                                                                                              \
  38     _Generic((dest),                                                                                                   \
  39         some_char_t *: PARSE_SOME_OF,                                                                                  \
  40         const char *: PARSE_LITERAL,                                                                                   \
  41         char *: PARSE_LITERAL,                                                                                         \
  42         const char **: PARSE_STRING,                                                                                   \
  43         char **: PARSE_STRING,                                                                                         \
  44         double *: PARSE_DOUBLE,                                                                                        \
  45         long *: PARSE_LONG,                                                                                            \
  46         bool *: PARSE_BOOL)
  47 
  48 #define as_void_star(x) ((void *)x)
  49 #define strparse(str, ...)                                                                                             \
  50     simpleparse(str, sizeof((const void *[]){__VA_ARGS__}) / sizeof(void *),                                           \
  51                 (parse_type_e[]){MAP_LIST(_parse_type, __VA_ARGS__)}, (void *[]){MAP_LIST(as_void_star, __VA_ARGS__)})
  52 #define fparse(file, ...)                                                                                              \
  53     ({                                                                                                                 \
  54         char *_file_contents = NULL;                                                                                   \
  55         size_t _capacity;                                                                                              \
  56         ssize_t _just_read = getdelim(&_file_contents, &_capacity, '\0', file);                                        \
  57         const char *_parse_err = _just_read > 0 ? strparse(_file_contents, __VA_ARGS__) : "No such file";              \
  58         if (_file_contents) free(_file_contents);                                                                      \
  59         _parse_err;                                                                                                    \
  60     })
  61 
  62 const char *simpleparse(const char *str, int n, parse_type_e types[n], void *destinations[n]);