StackReadingExample.cpp

Example of Reading a stack, converting and verifying types, and finally popping them all from the stack.

/*
Copyright (c) 2013, Komodo Does Inc
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THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
 
#include <memory>
#include <iostream>
#include <string>
#include <vector>
 
#include "Stack.h"
#include "Number.h"
#include "Variable.h"
#include "VariableSet.h"
#include "Error.h"
 
using namespace Calculator;
 
Result doSomething(Stack& stack) {
  // Create the values we will be reading.  I used item1..item5 for simplicity,
  // but useful names like top, firstNumber, variableToUpdate, maxValue, and
  // actualValue are obviously preferred.
  StackItem::Ptr item1;
  Number::Ptr item2;
  Variable::Ptr item3;
  Number::Ptr item4;
  Variable::Ptr item5;
  
  // Get the iterator and >> it to all the values.  Note the NO_DEREFERENCE_NEXT
  // type hints.  DEREFERENCE_NEXT is default and set after each read.
  StackIterator iter = stack.begin();
  iter >> item1
       >> item2
       >> StackIterator::Hint::NO_DEREFERENCE_NEXT >> item3
       >> item4
       >> item5;
 
  if(!iter) {
    return iter.getResult();
  }
 
  // Finally, all is well and we are ready to proceed:
  stack.popAfter(iter);
 
  // ...
  return Result();
}
 
int main(int argc, char** argv) {
  // The items we will be using
  Variable::Ptr variable = Variable::create("$test");
  Number::Ptr number = Number::create(1.2345);
  
  // Setup the stack and variables initial values
  Stack stack;
  stack.push(variable);
  stack.push(variable);
  stack.push(variable);
  stack.push(variable);
  stack.push(number);
 
  // Note that the variable is set after being used
  stack.getVariables().set(variable->getName(), number);
 
  // Do something with the result
  const Result result = doSomething(stack);
  std::cout << result.toString() << std::endl;
 
  return 0;
}