Package com.scriptbasic.interfaces

Interface LocalVariableMap

All Superinterfaces:

VariableMap

All Known Subinterfaces:

HierarchicalVariableMap

All Known Implementing Classes:

BasicLocalVariableMap, MixedBasicVariableMap

public interface LocalVariableMap
extends VariableMap

A variable map structure that can manage many maps in a stack structure. Any call to methods inherited from VariableMap works on the map at the top of the stack.

Author:

Peter Verhas date June 22, 2012

Method Summary

Modifier and Type	Method	Description
void	dropFrame()	Drop the current frame and pop off the map from the top of the stack.
void	newFrame()	Push the actual Map onto the stack of maps and create a new empty stack.
void	registerGlobalVariable(String variableName)	Register a variable as a global variable.
void	registerLocalVariable(String variableName)	Define the variable as a local variable in a local environment.

Methods inherited from interface com.scriptbasic.interfaces.VariableMap

getVariableNameSet, getVariableValue, setVariable, variableDefined, variableExists

Method Details

newFrame

void newFrame()

Push the actual Map onto the stack of maps and create a new empty stack. This is what a program has to do when a function is called. The local variables (if any) are pushed on the stack and a new stack frame is opened.

dropFrame

void dropFrame()

Drop the current frame and pop off the map from the top of the stack. This is what programs have to do when a RETURN is executed from a function.

registerGlobalVariable

void registerGlobalVariable(String variableName)
                     throws ScriptBasicException

Register a variable as a global variable. This is needed when an implementing class manages the global as well as the local variables.

Interpreters may handle variables differently. When a variable is not defined using some keyword as 'LOCAL' or 'GLOBAL' then the interpreter may treat the variable default local, may treat default global or may raise error. This is configurable in ScriptBasic.

This method can be used to declare that a variable is used in the local environment referring to the global variable.

Parameters:

variableName - parameter

Throws:

ScriptBasicException - in case of exception

registerLocalVariable

void registerLocalVariable(String variableName)
                    throws ScriptBasicException

Define the variable as a local variable in a local environment. For more information see the documentation of the method registerGlobalVariable(String)

Parameters:

variableName - parameter

Throws:

ScriptBasicException - in case of exception