X-Git-Url: https://git.danieliu.xyz/?a=blobdiff_plain;f=include%2Fcstack.h;h=bea73a6a223c503e04a25a530475b23a5d7101c7;hb=d4843ea375360f37e965709e73c0fbd68e302dca;hp=edb98475d1930b16d6a75760c4020f352f56bb02;hpb=584bba9e9357ff7adc0fcedf75fb098c359abb33;p=smdp.git

diff --git a/include/cstack.h b/include/cstack.h
index edb9847..bea73a6 100644
--- a/include/cstack.h
+++ b/include/cstack.h
@@ -1,6 +1,43 @@
 #if !defined( CSTACK_H )
 #define CSTACK_H
 
+/*
+ * An implementation of a char stack in heap memory.
+ * Copyright (C) 2014 Michael Goehler
+ *
+ * This file is part of mdp.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * struct: cstack_t which defines char stack type in heap memory
+ *
+ * function: cstack_init to intialize struct of type cstack_t
+ * function: cstack_t->push to add one char on top if the stack
+ * function: cstack_t->pop to remove the top char from the stack
+ * function: cstack_t->top to test if the top char is a given char
+ * function: cstack_t->empty to test if the stack is empty
+ * function: cstack_t->delete to free the allocated memory
+ *
+ * Example:
+ *      cstack_t *p = cstack_init();
+ *      (p->push)(p, 'X');
+ *      printf("%c\n", (p->pop)(p));
+ *      (p->delete)(p);
+ *
+ */
+
 typedef struct _cstack_t {
     char *content;
     size_t alloc;
@@ -8,15 +45,16 @@ typedef struct _cstack_t {
     int head;
     void (*push)(struct _cstack_t *self, char c);
     char (*pop)(struct _cstack_t *self);
-    char (*top)(struct _cstack_t *self);
+    int (*top)(struct _cstack_t *self, char c);
     int (*empty)(struct _cstack_t *self);
     void (*delete)(struct _cstack_t *self);
 } cstack_t;
 
+cstack_t *cstack_init();
 void cstack_push(cstack_t *self, char c);
 char cstack_pop(cstack_t *self);
-char cstack_top(cstack_t *self);
+int cstack_top(cstack_t *self, char c);
 int cstack_empty(cstack_t *self);
 void cstack_delete(cstack_t *self);
 
-#endif // !defined( CSTACK_H )
\ No newline at end of file
+#endif // !defined( CSTACK_H )