text: #include "expression_node.h"
  
  #include <stdio.h>
  #include <string.h>
  
  /**
   * Get display of individual expression node.
   */
  int EN_get_individual_display(ExpressionNode* self, char* buffer, size_t buffer_len) {
      if (strcmp(self->var, "") == 0) {
          snprintf(buffer, buffer_len, "%G", self->num);
      } else {
          if (self->num == 1) {
              snprintf(buffer, buffer_len, "%s", self->var);
          } else if (self->num == -1) {
              snprintf(buffer, buffer_len, "-%s", self->var);
          } else {
              snprintf(buffer, buffer_len, "%g%s", self->num, self->var);
          }
      }
      return 0;
  }
  