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128 lines
3.0 KiB
C++
Executable File
128 lines
3.0 KiB
C++
Executable File
// Copyright (C) 2009-2010 Lorenzo Caminiti.
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// Use, modification, and distribution is subject to the
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// Contract++ Software License, Version 1.0.
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// (See accompanying file LICENSE_1_0.txt.)
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// Contracts for an Eiffel-like stack (ported from Eiffel code).
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#ifndef STACK_HPP_
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#define STACK_HPP_
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#include <contract.hpp>
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#include <vector>
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/** Simple stack. */
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template<typename T>
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class stack {
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CONTRACT_INVARIANT( ({
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CONTRACT_ASSERT( count() >= 0 );
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}) )
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public:
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// Creation //
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/** Create empty stack. */
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stack(void): items_()
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CONTRACT_CONSTRUCTOR( (class) (stack)
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(public) (stack)( (void) )
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(postcondition) ({
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CONTRACT_ASSERT( count() == 0 );
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})
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(body) ({
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}) )
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/** Destroy stack. */
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~stack(void)
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CONTRACT_DESTRUCTOR( (class) (stack)
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(public) (stack)( (void) )
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(body) ({
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}) )
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// Basic Queries //
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/** Number of items. */
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int count(void) const
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CONTRACT_FUNCTION( (class) (stack)
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(public) (int) (count)( (void) ) (const)
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(body) ({
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return items_.size();
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}) )
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/** Item at index in [1, count()] (Eiffel index starts at 1). */
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const T& item_at(const int& index) const
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CONTRACT_FUNCTION( (class) (stack)
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(public) (const T&) (item_at)( (const int&)(index) )
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(const)
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(precondition) ({
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CONTRACT_ASSERT( index >= 1 );
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CONTRACT_ASSERT( index <= count() );
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})
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(body) ({
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return items_.at(index - 1);
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}) )
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// Derived Queries //
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/** If no items. */
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bool is_empty(void) const
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CONTRACT_FUNCTION( (class) (stack)
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(public) (bool) (is_empty)( (void) ) (const)
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(postcondition) (result) ({
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CONTRACT_ASSERT( result == (count() == 0) );
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})
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(body) ({
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return items_.size() == 0;
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}) )
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/** Top item. */
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const T& item(void) const
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CONTRACT_FUNCTION( (class) (stack)
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(public) (const T&) (item)( (void) ) (const)
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(precondition) ({
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CONTRACT_ASSERT( count() > 0 );
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})
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(postcondition) (result) ({
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CONTRACT_ASSERT( result == item_at(count()) );
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})
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(body) ({
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return items_.at(items_.size() - 1);
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}) )
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// Commands //
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/** Push new item to the top. */
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void put(const T& new_item)
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CONTRACT_FUNCTION( (class) (copyable)(stack)
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(public) (void) (put)( (const T&)(new_item) )
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(postcondition) ({
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CONTRACT_ASSERT( count() ==
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(CONTRACT_OLDOF(this)->count() + 1) );
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CONTRACT_ASSERT( item() == new_item );
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})
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(body) ({
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items_.push_back(new_item);
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}) )
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/** Pop top item. */
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void remove(void)
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CONTRACT_FUNCTION( (class) (copyable)(stack)
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(public) (void) (remove)( (void) )
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(precondition) ({
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CONTRACT_ASSERT( count() > 0 );
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})
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(postcondition) ({
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CONTRACT_ASSERT( count() ==
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(CONTRACT_OLDOF(this)->count() - 1) );
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})
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(body) ({
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items_.resize(items_.size() - 1);
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}) )
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private:
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std::vector<T> items_;
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};
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#endif // #include guard
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