GNU Astronomy Utilities


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10.3.7.2 List of int32_t

Signed integers are the best types when you are dealing with a positive or negative integers. The are generally useful in many contexts, for example when you want to keep the order of a series of states (each state stored as a given number in an enum for example). On many modern systems, int32_t is just an alias for int, so you can use them interchangeably. To make sure, check the size of int on your system:

Type (C struct): gal_list_i32_t

A single node in a list containing a 32-bit signed integer (see Numeric data types).

typedef struct gal_list_i32_t
{
  int32_t v;
  struct gal_list_i32_t *next;
} gal_list_i32_t;
Function:
void
gal_list_i32_add (gal_list_i32_t **list, int32_t value)

Add a new node (containing value) to the top of the list of int32_ts (uint32_t is equal to int on many modern systems), and update list. Here is one short example of initializing and adding elements to a string list:

gal_list_i32_t *i32list=NULL;
gal_list_i32_add(&i32list, 52);
gal_list_i32_add(&i32list, -4);
Function:
int32_t
gal_list_i32_pop (gal_list_i32_t **list)

Pop the top element of list and return the value. This function will also change list to point to the next node in the list. If *list==NULL, then this function will also return GAL_BLANK_INT32 (see Library blank values (blank.h)).

Function:
size_t
gal_list_i32_number (gal_list_i32_t *list)

Return the number of nodes in list.

Function:
void
gal_list_i32_print (gal_list_i32_t *list)

Print the integers within each node of *list on the standard output in the same order that they are stored. Each integer is printed on one line. This function is mainly good for checking/debugging your program. For program outputs, its best to make your own implementation with a better, more user-friendly format. For example the following code snippet. You can also modify it to print all values in one line, and etc, depending on the context of your program.

size_t i;
gal_list_i32_t *tmp;
for(tmp=list; tmp!=NULL; tmp=tmp->next)
  printf("String %zu: %s\n", i, tmp->v);
Function:
void
gal_list_i32_reverse (gal_list_i32_t **list)

Reverse the order of the list such that the top node in the list before calling this function becomes the bottom node after it.

Function:
int32_t *
gal_list_i32_to_array (gal_list_i32_t *list, int reverse, size_t *num)

Dynamically allocate an array and fill it with the values in list. The function will return a pointer to the allocated array and put the number of elements in the array into the num pointer. If reverse has a non-zero value, the array will be filled in the opposite order of elements in list. This function can be useful after you have finished reading an initially unknown number of values and want to put them in an array for easy random access.

Function:
void
gal_list_i32_free (gal_list_i32_t *list)

Free every node in list.


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