matched

matched.c

#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

struct Exp_T {
  const char *str;
  int index;
  int length;
  int token;
};

struct Exp_T initExpT(char *argv[]) {
  struct Exp_T exp_T = {
      .str = argv[1], .index = 0, .length = (int)strlen(argv[1])};
  return exp_T;
}

void getToken(struct Exp_T *exp) {
  exp->token = exp->str[exp->index];
  exp->index++;
}

void r(struct Exp_T *exp);
void s(struct Exp_T *exp) { r(exp); }

void r(struct Exp_T *exp) {
  if (exp->token != '(') {
    return;
  }
  getToken(exp);
  s(exp);
  if (exp->token != ')') {
    fprintf(stderr, "Unmatched\n");
    return;
  }
  getToken(exp);
  s(exp);
}

/* Provide the parenthesized expression with CLI args */
int main(int argc, char *argv[]) {
  struct Exp_T exp = initExpT(argv);

  while (exp.index < exp.length) {
    getToken(&exp);
    s(&exp);
  }

  return EXIT_SUCCESS;
}