ExpressionLogical.cpp

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/******************************************************************************/
/* REXX Translator                                                            */
/*                                                                            */
/* Primitive logical list evaluator                                           */
/*                                                                            */
/******************************************************************************/
#include <stdlib.h>
#include "RexxCore.h"
#include "StringClass.hpp"
#include "QueueClass.hpp"
#include "RexxActivation.hpp"
#include "RexxInstruction.hpp"
#include "ExpressionLogical.hpp"
#include "StackClass.hpp"
#include "RexxActivity.hpp"
#include "BuiltinFunctions.hpp"
#include "SourceFile.hpp"
 
/**
 * Constructor for a RexxExpressionLogical object.
 *
 * @param source The source parsing context (used for raising errors)
 * @param count  The number of expressions in the list.
 * @param list   The accumulated list of expressions.
 */
RexxExpressionLogical::RexxExpressionLogical(RexxSource *source, size_t count, RexxQueue  *list)
{
    expressionCount = count;
 
    // the parsed expressions are stored in a queue, so we process them in
    // reverse order.
    while (count > 0)
    {
        RexxObject *condition = list->pop();
        if (condition == OREF_NULL)
        {
            source->syntaxError(Error_Invalid_expression_logical_list);
        }
        OrefSet(this, this->expressions[--count], condition);
    }
}
 
/**
 * The runtime, non-debug live marking routine.
 */
void RexxExpressionLogical::live(size_t liveMark)
{
  size_t  i;                           /* loop counter                      */
  size_t  count;                       /* argument count                    */
 
  for (i = 0, count = this->expressionCount; i < count; i++)
  {
      memory_mark(this->expressions[i]);
  }
}
 
/**
 * The generalized live marking routine used for non-performance
 * critical marking operations.
 */
void RexxExpressionLogical::liveGeneral(int reason)
{
  size_t  i;                           /* loop counter                      */
  size_t  count;                       /* argument count                    */
 
  for (i = 0, count = this->expressionCount; i < count; i++)
  {
      memory_mark_general(this->expressions[i]);
  }
}
 
/**
 * The flattening routine, used for serializing object trees.
 *
 * @param envelope The envelope were's flattening into.
 */
void RexxExpressionLogical::flatten(RexxEnvelope *envelope)
{
  size_t  i;                           /* loop counter                      */
  size_t  count;                       /* argument count                    */
 
  setUpFlatten(RexxExpressionLogical)
 
  for (i = 0, count = this->expressionCount; i < count; i++)
  {
      flatten_reference(newThis->expressions[i], envelope);
  }
 
  cleanUpFlatten
}
 
/**
 * Evaluate a logical expresion list.
 *
 * @param context The execution context.
 * @param stack   The evaluation stack.
 *
 * @return The result of the operation, either .true or .false.
 */
RexxObject *RexxExpressionLogical::evaluate(RexxActivation *context, RexxExpressionStack *stack)
{
    // loop through the expression list evaulating and then testing for the
    // logical value
    size_t count = expressionCount;
    // there are no optional values in the list, so evaluate unconditionally.
    for (size_t i = 0; i < count; i++)
    {
        // evaluate and trace
        RexxObject *value = expressions[i]->evaluate(context, stack);
        context->traceResult(value);
 
        // the comparison methods return either .true or .false, so we
        // can to a quick test against those.
        if (value != TheTrueObject)    // most of the time, these will be true so test that first.
        {
            if (value == TheFalseObject)
            {
                return TheFalseObject;
            }
            // ok, the either returned a '0' or a '1' that was not the result of returning
            // .true or .false, or we have a bad value.
            if (!value->truthValue(Error_Logical_value_logical_list))
            {
                return TheFalseObject;    // we terminate on the first false condition
            }
        }
    }
    return TheTrueObject;      // all is truth
}
 
/**
 * Create a new logical list object.
 *
 * @param size   The size of the class object.
 * @param count  The count of logical expressions.  Used to adjust the
 *               allocated size to the requirements.
 *
 * @return A new RexxExpressionLogical object.
 */
void *RexxExpressionLogical::operator new(size_t size, size_t  count)
{
                                         /* Get new object                    */
    return new_object(size + (count - 1) * sizeof(RexxObject *), T_LogicalTerm);
}