Package com.scriptbasic.interfaces

Interface VariableMap

All Known Subinterfaces:
HierarchicalVariableMap, LocalVariableMap
All Known Implementing Classes:
BasicLocalVariableMap, MixedBasicVariableMap
public interface VariableMap
Manage local or global variables. One Map manages the global variables in a BASIC program. There is a map for each local level of function calls storing the local variables. This interface is also implemented by the MixedBasicVariableMap that manages the global and the local variables transparently.

The methods may throw ScriptBasicException. The interface provides this possibility to implement features like denying case sensitive reuse of variable names. For example jScriptBasic does not allow you to use the variable Apple is ever you already used apple. In other basic implementations the casing is insensitive and the two variable names are the same. Other languages treat Apple and apple as two different variables. jScriptBasic believes that both practices are bad.

Author:
Peter Verhas date June 22, 2012

  • Method Details

    • getVariableValue

      RightValue getVariableValue(String variableName) throws ScriptBasicException
      Get the value of a variable.
      Parameters:
      variableName - parameter
      Returns:
      the right value the variable has or null if the variable is not defined or does not exists.
      Throws:
      ScriptBasicException - in case there is an exception

    • variableExists

      Boolean variableExists(String variableName) throws ScriptBasicException
      Checks that a variable exists in this map.
      Parameters:
      variableName - parameter
      Returns:
      true if the variable exists, even if the variable has undefined value. false if the variable does not exist in this map.
      Throws:
      ScriptBasicException - in case there is an exception

    • variableDefined

      Boolean variableDefined(String variableName) throws ScriptBasicException
      Checks that a variable exists and has a defined value in this map. Undefined value is represented by null.
      Parameters:
      variableName - parameter
      Returns:
      true if the variable exists and has a defined value.
      Throws:
      ScriptBasicException - in case there is an exception

    • setVariable

      void setVariable(String variableName, RightValue rightValue) throws ScriptBasicException
      Set the value of the variable. If the variable did not exist then the variable is automatically created. If the variable had undefined value then the new value will be the one defined by the argument.

      You can set a variable to undefined passing null to this method as rightValue.

      Parameters:
      variableName - parameter
      rightValue - the new value of the variable
      Throws:
      ScriptBasicException - in case there is an exception

    • getVariableNameSet

      Set<String> getVariableNameSet()
      Get the set of the variables stored in the variable map so that the caller can iterate through the variables.
      Returns:
      return value