Chapter 4. YCP Type System

Chapter 4. YCP Type System
	The YaST Programming Language - YCP

Table of Contents

4.1. Data Type any And Type Checking

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4.1. Data Type any And Type Checking

In Data type any you have seen the data type any. Because the value of type any can not be assigned to a variable of any other type. FIXME. So it is important to check its type with is(...) and then re-assigning it to a variable of the correct type. The following example shows how this should be done.

Example 4.1. Type checking and data type any

//
// Hypothetical example:
// ---------------------
// We don't know whether the SCR will return integers or floats...
//
any     any_var   = 0;
integer int_var   = 0;
float   float_var = 0.0;
boolean int_case  = false;

any_var = SCR::Read(...);

if ( is( any_var, integer ) )
{
   int_var  = any_var;
   int_case = true;
}
else if ( is( any_var, float ) )
{
   float_var = any_var;
   int_case  = false;
}
else
{
   // Error...
}

if ( int_case )
{
   // Use int_var...
}
else
{
   // Use float_var...
}

As this is very cumbersome, you should try to avoid this oddity in any case. If it is ineluctable, do it as shown above to stay compatible with future YaST behavior.


Chapter 3. More YCP types		Chapter 5. YCP Expression Evaluation