[随手写一个] 字符串实现

明天CET4了，随便写点啥压压惊好了。

// File: heap_string.h#ifndef __HEADER__HEAP_STRING_H#define __HEADER__HEAP_STRING_Htypedef struct hstring_t {    char *data;    int length;    int size;} *hstring_t;hstring_t hs_create();void hs_destory(hstring_t str);void hs_assign(hstring_t str, const char *st);void hs_resize(hstring_t str, int ref);const char *hs_get(hstring_t str);int hs_length(hstring_t str);const char hs_at(hstring_t str, int idx);const char hs_at_unsafe(hstring_t str, int idx);void hs_append_string(hstring_t str, const char *s);void hs_append_character(hstring_t str, char ch);void hs_append_integer(hstring_t str, long x);#define hs_append(str, x) _Generic((x), char *: hs_append_string,    \                                        int   : hs_append_character, \                                        char  : hs_append_character, \                                        long  : hs_append_integer) (str, x)#endif // __HEADER__HEAP_STRING_H// File: heap_string.c#include "heap_string.h"#include<string.h>#include<stdlib.h>hstring_t hs_create(){    hstring_t ret = (hstring_t)malloc(sizeof(hstring_t));    ret->length = 0;    ret->size = 10;    ret->data = (char *)malloc(ret->size * sizeof(char));    return ret;}void hs_destory(hstring_t str){    free(str->data);    free(str);}void hs_assign(hstring_t str, const char *st){    int new_length = strlen(st);    if (new_length < str->length) {        hs_resize(str, new_length);    }    strcpy(str->data, st);    str->length = new_length;}const char *hs_get(hstring_t str){    return str->data;}int hs_length(hstring_t str){    return str->length;}const char hs_at(hstring_t str, int idx){    if (idx < str->length) {        return str->data[idx];    }    return '\0';}const char hs_at_unsafe(hstring_t str, int idx){    return str->data[idx];}void hs_resize(hstring_t str, int ref){    static const int MIDVALUE = 1000;    int new_size = str->size;    while (new_size < ref) {        new_size *= (str->size < MIDVALUE) ? 1.5 : 2;    }    char *new_buffer = (char *)malloc(new_size * sizeof(char));    strcpy(new_buffer, str->data);    free(str->data);    str->data = new_buffer;    str->size = new_size;}void hs_append_string(hstring_t str, const char *s){    int new_length = str->length + strlen(s);    if (new_length > str->size) {        hs_resize(str, new_length);    }    strcpy(str->data + str->length, s);    str->length = new_length;}void hs_append_character(hstring_t str, char ch){    int new_length = str->length + sizeof(ch);    if (new_length > str->size) {        hs_resize(str, new_length);    }    str->data[str->length] = ch;    str->data[str->length + 1] = '\0';    str->length++;}void hs_append_integer(hstring_t str, long x){    char buffer[25];    sprintf(buffer, "%ld", x);    hs_append_string(str, buffer);}// File: test.c#include"heap_string.h"#include<stdio.h>int main(int argc, char *argv[]){    hstring_t str = hs_create();    hs_assign(str, "Hello");    hs_append(str, ',');    hs_append(str, "world.");    hs_append(str, 1001010101L);    puts(hs_get(str));    hs_destory(str);}