Simplifying parsing and data structure building

• Parsing of stdin was simplified by using conventional stdlib functions
  rather than parsing the stdin byte-by-byte.
• Splited parsing of textual input and building of internal data
  structures into two different functions.

diff --git a/xmenu.c b/xmenu.c
index 7127914..5fefae8 100644 (file)
--- a/xmenu.c
+++ b/xmenu.c
@@ -73,6 +73,7 @@ static void setupdc(void);
 static void calcgeom(void);
 static struct Item *allocitem(const char *label, const char *output);
 static struct Menu *allocmenu(struct Menu *parent, struct Item *list, unsigned level);
 static void calcgeom(void);
 static struct Item *allocitem(const char *label, const char *output);
 static struct Menu *allocmenu(struct Menu *parent, struct Item *list, unsigned level);

+static struct Menu * buildmenutree(unsigned level, const char *label, const char *output);

 static struct Menu *parsestdin(void);
 static void calcmenu(struct Menu *menu);
 static void grabpointer(void);
 static struct Menu *parsestdin(void);
 static void calcmenu(struct Menu *menu);
 static void grabpointer(void);


@@ -251,7 +252,7 @@ allocitem(const char *label, const char *output)
 
        if ((item = malloc(sizeof *item)) == NULL)
                err(1, "malloc");
 
        if ((item = malloc(sizeof *item)) == NULL)
                err(1, "malloc");

-       if (*label == '\0') {
+       if (label == NULL) {

                item->label = NULL;
                item->output = NULL;
        } else {
                item->label = NULL;
                item->output = NULL;
        } else {


@@ -310,96 +311,92 @@ allocmenu(struct Menu *parent, struct Item *list, unsigned level)
        return menu;
 }
 
        return menu;
 }
 

-/* create menus and items from the stdin */
+/* build the menu tree */

 static struct Menu *
 static struct Menu *

-parsestdin(void)
+buildmenutree(unsigned level, const char *label, const char *output)

 {
 {

-       char *s, buf[BUFSIZ];
-       char *label, *output;
-       unsigned level = 0;
+       static struct Menu *prevmenu = NULL;    /* menu the previous item was added to */
+       static struct Menu *rootmenu = NULL;    /* menu to be returned */
+       struct Item *curritem = NULL;           /* item currently being read */
+       struct Item *item;                      /* dummy item for loops */
+       struct Menu *menu;                      /* dummy menu for loops */

        unsigned i;
        unsigned i;

-       struct Item *curritem = NULL;   /* item currently being read */
-       struct Menu *prevmenu = NULL;   /* menu the previous item was added to */
-       struct Item *item;              /* dummy item for loops */
-       struct Menu *menu;              /* dummy menu for loops */
-       struct Menu *rootmenu;          /* menu to be returned */
-
-       rootmenu = NULL;
-
-       while (fgets(buf, BUFSIZ, stdin) != NULL) {
-               level = 0;
-               s = buf;
-
-               while (*s == '\t') {
-                       level++;
-                       s++;
-               }

 
 

-               label = output = s;
-
-               while (*s != '\0' && *s != '\t' && *s != '\n')
-                       s++;
-
-               while (*s == '\t')
-                       *s++ = '\0';
-
-               if (*s != '\0' && *s != '\n')
-                       output = s;
-
-               while (*s != '\0' && *s != '\n')
-                       s++;
-
-               if (*s == '\n')
-                       *s = '\0';
-
-               curritem = allocitem(label, output);
-
-               if (prevmenu == NULL) {                 /* there is no menu yet */
-                        menu = allocmenu(NULL, curritem, level);
-                        rootmenu = menu;
-                        prevmenu = menu;
-                        curritem->prev = NULL;
-                        curritem->next = NULL;
-               } else if (level < prevmenu->level) {   /* item is continuation of a parent menu*/
-                       for (menu = prevmenu, i = level;
-                             menu != NULL && i < prevmenu->level;
-                             menu = menu->parent, i++)
-                               ;
-
-                       if (menu == NULL)
-                               errx(1, "reached NULL menu");
+       /* create the item */
+       curritem = allocitem(label, output);
+
+       /* put the item in the menu tree */
+       if (prevmenu == NULL) {                 /* there is no menu yet */
+                menu = allocmenu(NULL, curritem, level);
+                rootmenu = menu;
+                prevmenu = menu;
+                curritem->prev = NULL;
+       } else if (level < prevmenu->level) {   /* item is continuation of a parent menu */
+               /* go up the menu tree until find the menu this item continues */
+               for (menu = prevmenu, i = level;
+                         menu != NULL && i != prevmenu->level;
+                         menu = menu->parent, i++)
+                       ;
+               if (menu == NULL)
+                       errx(1, "reached NULL menu");

 
 

-                       for (item = menu->list; item->next != NULL; item = item->next)
-                               ;
+               /* find last item in the new menu */
+               for (item = menu->list; item->next != NULL; item = item->next)
+                       ;

 
 

-                       item->next = curritem;
+               prevmenu = menu;
+               item->next = curritem;
+               curritem->prev = item;
+       } else if (level == prevmenu->level) {  /* item is a continuation of current menu */
+               /* find last item in the previous menu */
+               for (item = prevmenu->list; item->next != NULL; item = item->next)
+                       ;

 
 

-                       curritem->prev = item;
-                       curritem->next = NULL;
+               item->next = curritem;
+               curritem->prev = item;
+       } else if (level > prevmenu->level) {   /* item begins a new menu */
+               menu = allocmenu(prevmenu, curritem, level);

 
 

-                       prevmenu = menu;
-               } else if (level == prevmenu->level) {  /* item is a continuation of current menu */
-                       for (item = prevmenu->list; item->next != NULL; item = item->next)
-                               ;
-                       item->next = curritem;
+               /* find last item in the previous menu */
+               for (item = prevmenu->list; item->next != NULL; item = item->next)
+                       ;

 
 

-                       curritem->prev = item;
-                       curritem->next = NULL;
+               prevmenu = menu;
+               menu->caller = item;
+               item->submenu = menu;
+               curritem->prev = NULL;
+       }

 
 

-               } else if (level > prevmenu->level) {   /* item begins a new menu */
-                       menu = allocmenu(prevmenu, curritem, level);
+       return rootmenu;
+}

 
 

-                       for (item = prevmenu->list; item->next != NULL; item = item->next)
-                               ;
+/* create menus and items from the stdin */
+static struct Menu *
+parsestdin(void)
+{
+       struct Menu *rootmenu;
+       char *s, buf[BUFSIZ];
+       char *label, *output;
+       unsigned level = 0;

 
 

-                       item->submenu = menu;
-                       menu->caller = item;
+       while (fgets(buf, BUFSIZ, stdin) != NULL) {
+               /* get the indentation level */
+               level = strspn(buf, "\t");

 
 

-                       curritem->prev = NULL;
-                       curritem->next = NULL;
+               /* get the label */
+               s = level + buf;
+               label = strtok(s, "\t\n");

 
 

-                       prevmenu = menu;
+               /* get the output */
+               output = strtok(NULL, "\n");
+               if (output == NULL) {
+                       output = label;
+               } else {
+                       while (*output == '\t')
+                               output++;

                }
                }

+
+               rootmenu = buildmenutree(level, label, output);

        }
 
        return rootmenu;
        }
 
        return rootmenu;