format.cpp

#include "format.h"
#include "lexer.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

extern FILE *fp;
extern char token_text[MAXLEN];

void format()
{
    int tabs = 0; // 控制缩进
    int i;
    int flag = 0; // 用于标记无大括号但需要缩进的情况
    token *root, *tail, *p;
    while (1)
    {
        root = readline();
        if (root == NULL)
            break;
        tail = root;
        while (tail->next != NULL)
            tail = tail->next;
        if ((root == tail) && (strcmp(tail->str, "}") == 0))
            tabs--;
        if ((root != tail) && (strcmp(root->str, "}") == 0))
            tabs--;
        for (i = 0; i < tabs; i++) // 输出缩进
            printf("\t");
        if (flag == 1)
        {
            tabs--;
            flag = 0;
        }
        p = root;
        while (p != NULL)
        {
            printf("%s ", p->str);
            p = p->next;
        }
        printf("\n");
        if (strcmp(tail->str, "{") == 0)
            tabs++;
        p = root;
        while (p != NULL)
        {
            if ((strcmp(p->str, "if") == 0) || (strcmp(p->str, "for") == 0) || (strcmp(p->str, "while") == 0))
            {
                if (strcmp(tail->str, "{") != 0 && strcmp(tail->str, ";") != 0)
                {
                    tabs++;
                    flag = 1;
                }
            }
            p = p->next;
        }
    }
}

token *readline()
{
    char c;
    int w;
    token *root = NULL;
    token *tail = root; //完成初始化
    memset(token_text, 0, sizeof(token_text));
    w = gettoken(fp);
    if (w == EndOfFile)
        return NULL;
    root = (token *)malloc(sizeof(token));
    root->str = (char *)malloc(MAXLEN*sizeof(char));
    strcpy(root->str, token_text);
    root->next = NULL;
    tail = root;
    /* 每识别一个单词判断单词后面是不是换行符 */
    while (((c = fgetc(fp)) != '\n') && (c != EOF))
    {
        ungetc(c, fp);
        memset(token_text, 0, sizeof(token_text));
        gettoken(fp);
        tail->next = (token *)malloc(sizeof(token));
        tail = tail->next;
        tail->str = (char *)malloc(MAXLEN*sizeof(char));
        strcpy(tail->str, token_text);
        tail->next = NULL;
    }
    return root;
}