Initial Commit

OU3/include/stack.h

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+#ifndef __STACK_H
+#define __STACK_H
+
+#include <stdbool.h>
+#include "util.h"
+
+/*
+ * Declaration of a generic stack for the "Datastructures and
+ * algorithms" courses at the Department of Computing Science, Umea
+ * University. The stack stores void pointers, so it can be used to
+ * store all types of values. After use, the function stack_kill must
+ * be called to de-allocate the dynamic memory used by the stack
+ * itself. The de-allocation of any dynamic memory allocated for the
+ * element values is the responsibility of the user of the stack,
+ * unless a kill_function is registered in stack_empty.
+ *
+ * Authors: Niclas Borlin (niclas@cs.umu.se)
+ *          Adam Dahlgren Lindstrom (dali@cs.umu.se)
+ *
+ * Based on earlier code by: Johan Eliasson (johane@cs.umu.se).
+ *
+ * Version information:
+ *   v1.0  2018-01-28: First public version.
+ *   v1.1  2024-05-10: Added/updated print_internal to enhance encapsulation.
+ */
+
+// ==========PUBLIC DATA TYPES============
+
+// Stack type.
+typedef struct stack stack;
+
+// ==========DATA STRUCTURE INTERFACE==========
+
+/**
+ * stack_empty() - Create an empty stack.
+ * @kill_func: A pointer to a function (or NULL) to be called to
+ *             de-allocate memory on remove/kill.
+ *
+ * Returns: A pointer to the new stack.
+ */
+stack *stack_empty(kill_function kill_func);
+
+/**
+ * stack_is_empty() - Check if a stack is empty.
+ * @s: Stack to check.
+ *
+ * Returns: True if stack is empty, otherwise false.
+ */
+bool stack_is_empty(const stack *s);
+
+/**
+ * stack_push() - Push a value on top of a stack.
+ * @s: Stack to manipulate.
+ * @v: Value (pointer) to be put on the stack.
+ *
+ * Returns: The modified stack.
+ *          NOTE: After the call, the input stack should be considered invalid.
+ */
+stack *stack_push(stack *s, void *v);
+
+/**
+ * stack_pop() - Remove the element at the top of a stack.
+ * @s: Stack to manipulate.
+ *
+ * NOTE: Undefined for an empty stack.
+ *
+ * Returns: The modified stack.
+ *          NOTE: After the call, the input stack should be considered invalid.
+ */
+stack *stack_pop(stack *s);
+
+/**
+ * stack_top() - Inspect the value at the top of the stack.
+ * @s: Stack to inspect.
+ *
+ * Returns: The value at the top of the stack.
+ *          NOTE: The return value is undefined for an empty stack.
+ */
+void *stack_top(const stack *s);
+
+/**
+ * stack_kill() - Destroy a given stack.
+ * @s: Stack to destroy.
+ *
+ * Return all dynamic memory used by the stack and its elements. If a
+ * kill_func was registered at stack creation, also calls it for each
+ * element to kill any user-allocated memory occupied by the element values.
+ *
+ * Returns: Nothing.
+ */
+void stack_kill(stack *s);
+
+/**
+ * stack_print() - Iterate over the stack elements and print their values.
+ * @s: Stack to inspect.
+ * @print_func: Function called for each element.
+ *
+ * Iterates over the stack and calls print_func with the value stored
+ * in each element.
+ *
+ * Returns: Nothing.
+ */
+void stack_print(const stack *s, inspect_callback print_func);
+
+/**
+ * stack_print_internal() - Print the stacks internal structure in dot format.
+ * @l: Stack to inspect.
+ * @print_func: Function called for each element value.
+ * @desc: String with a description/state of the stack, or NULL for no description.
+ * @indent_level: Indentation level, 0 for outermost
+ *
+ * Iterates over the stack and outputs dot code that shows the internal
+ * structure of the stack.  The dot code can be visualized by
+ * Graphviz.
+ *
+ * On linux system, the output can be parsed by the dot program, e.g.
+ *
+ *   <stack_program> | dot -Tsvg > /tmp/dot.svg; firefox /tmp/dot.svg
+ *
+ * where <stack_program> is the name of the executable
+ *
+ * The output may also be possible to visualize online on
+ * https://dreampuf.github.io/GraphvizOnline/ or google "graphviz
+ * online".
+ *
+ * For documention of the dot language, see graphviz.org.
+ *
+ * Returns: Nothing.
+ */
+void stack_print_internal(const stack *s, inspect_callback print_func, const char *desc,
+                          int indent_level);
+
+#endif