lua/isocline/src/undo.c

   1 /* ----------------------------------------------------------------------------
   2   Copyright (c) 2021, Daan Leijen
   3   This is free software; you can redistribute it and/or modify it
   4   under the terms of the MIT License. A copy of the license can be
   5   found in the "LICENSE" file at the root of this distribution.
   6 -----------------------------------------------------------------------------*/
   7 #include <string.h>
   8 #include <stdio.h>
   9
  10 #include "../include/isocline.h"
  11 #include "common.h"
  12 #include "env.h"
  13 #include "stringbuf.h"
  14 #include "completions.h"
  15 #include "undo.h"
  16
  17
  18
  19 //-------------------------------------------------------------
  20 // edit state
  21 //-------------------------------------------------------------
  22 struct editstate_s {
  23   struct editstate_s* next;
  24   const char* input;          // input
  25   ssize_t     pos;            // cursor position
  26 };
  27
  28 ic_private void editstate_init( editstate_t** es ) {
  29   *es = NULL;
  30 }
  31
  32 ic_private void editstate_done( alloc_t* mem, editstate_t** es ) {
  33   while (*es != NULL) {
  34     editstate_t* next = (*es)->next;
  35     mem_free(mem, (*es)->input);
  36     mem_free(mem, *es );
  37     *es = next;
  38   }
  39   *es = NULL;
  40 }
  41
  42 ic_private void editstate_capture( alloc_t* mem, editstate_t** es, const char* input, ssize_t pos) {
  43   if (input == NULL) { input = ""; }
  44   // alloc
  45   editstate_t* entry = mem_zalloc_tp(mem, editstate_t);
  46   if (entry == NULL) { return; }
  47   // initialize
  48   entry->input = mem_strdup( mem, input);
  49   entry->pos   = pos;
  50   if (entry->input == NULL) { mem_free(mem, entry); return; }
  51   // and push
  52   entry->next = *es;
  53   *es = entry;
  54 }
  55
  56 // caller should free *input
  57 ic_private bool editstate_restore( alloc_t* mem, editstate_t** es, const char** input, ssize_t* pos ) {
  58   if (*es == NULL) { return false; }
  59   // pop
  60   editstate_t* entry = *es;
  61   *es = entry->next;
  62   *input = entry->input;
  63   *pos = entry->pos;
  64   mem_free(mem, entry);
  65   return true;
  66 }