stack_int

stack_int is a small, stack-based implementation of arbitrary-precision integers written in ANSI C. No dependencies are needed besides <stdint.h>. Negative integers are not supported for the moment.

Sample Code

#include <stack_int.h>

int main() {
  stack_int a, b, c;

  si_from_ascii("2000000", 7, 10, 10, &a);
  si_from_ascii("3000000", 7, 10, 10, &b);

  si_add(&a, &b, &c);

  char buf[128];
  si_to_ascii(&c, buf, 128);

  printf("a = %s\n", buf);

  return 1;
}

Building

The entire implementation is found in the stack_int.c file. If you add a new function, make sure you add a matching test file inside of the tests/ directory. To build a library containing the si_* functions, you can run:

$ make build/libstack_int.a

Unit Tests

The simple unit test structure is taken from Zed Shaw's free book Learn C the Hard Way. To run the test suite:

$ make tests