Package com.scriptbasic.memory

Class BasicLocalVariableMap

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      protected java.lang.String converted​(java.lang.String name)
      Converts the name of a variable in a way that if the name 'a' and name 'b' results the same string converted then 'a' and 'b' are treated from some aspects as the same variable name.
      boolean currentScopeIsGlobal()
      Returns true if the current scope is global, there no no any local stack frame open.
      void dropFrame()
      Drop the current frame and pop off the map from the top of the stack.
      java.util.Set<java.lang.String> getVariableNameSet()
      Get the set of the variables stored in the variable map so that the caller can iterate through the variables.
      RightValue getVariableValue​(java.lang.String variableName)
      Get the value of a variable.
      boolean isGlobal​(java.lang.String variableName)  
      boolean isLocal​(java.lang.String variableName)  
      void newFrame()
      Push the actual Map onto the stack of maps and create a new empty stack.
      void registerGlobalVariable​(java.lang.String variableName)
      Register a variable as a global variable.
      void registerLocalVariable​(java.lang.String variableName)
      Define the variable as a local variable in a local environment.
      void setCaseFreak()
      Tell the object that the variable names has to be cased only one way.
      void setCaseIgnorant()
      Tell the object that the variable handling is case insensitive.
      void setCaseSensitive()
      Tell the object that the variable names are handled in a case sensitive way.
      void setVariable​(java.lang.String variableName, RightValue rightValue)
      Set the value of the variable.
      java.lang.Boolean variableDefined​(java.lang.String variableName)
      Checks that a variable exists and has a defined value in this map.
      java.lang.Boolean variableExists​(java.lang.String variableName)
      Checks that a variable exists in this map.

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

    • Constructor Detail

      • BasicLocalVariableMap

        public BasicLocalVariableMap()

    • Method Detail

      • getVariableValue

        public RightValue getVariableValue​(java.lang.String variableName)
                            throws ScriptBasicException
        Description copied from interface: VariableMap
        Get the value of a variable.
        Specified by:
        getVariableValue in interface VariableMap
        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

        public java.lang.Boolean variableExists​(java.lang.String variableName)
                                 throws ScriptBasicException
        Description copied from interface: VariableMap
        Checks that a variable exists in this map.
        Specified by:
        variableExists in interface VariableMap
        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

        public java.lang.Boolean variableDefined​(java.lang.String variableName)
                                  throws ScriptBasicException
        Description copied from interface: VariableMap
        Checks that a variable exists and has a defined value in this map. Undefined value is represented by null.
        Specified by:
        variableDefined in interface VariableMap
        Parameters:
        variableName - parameter
        Returns:
        true if the variable exists and has a defined value.
        Throws:
        ScriptBasicException - in case there is an exception

      • setVariable

        public void setVariable​(java.lang.String variableName,
                        RightValue rightValue)
                 throws ScriptBasicException
        Description copied from interface: VariableMap
        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.

        Specified by:
        setVariable in interface VariableMap
        Parameters:
        variableName - parameter
        rightValue - the new value of the variable
        Throws:
        ScriptBasicException - in case there is an exception

      • newFrame

        public void newFrame()
        Description copied from interface: LocalVariableMap
        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.
        Specified by:
        newFrame in interface LocalVariableMap

      • dropFrame

        public void dropFrame()
        Description copied from interface: LocalVariableMap
        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.
        Specified by:
        dropFrame in interface LocalVariableMap

      • currentScopeIsGlobal

        public boolean currentScopeIsGlobal()
        Returns true if the current scope is global, there no no any local stack frame open.
        Returns:
        return value

      • registerGlobalVariable

        public void registerGlobalVariable​(java.lang.String variableName)
                            throws ScriptBasicException
        Description copied from interface: LocalVariableMap
        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.

        Specified by:
        registerGlobalVariable in interface LocalVariableMap
        Parameters:
        variableName - parameter
        Throws:
        ScriptBasicException - in case of exception

      • getVariableNameSet

        public java.util.Set<java.lang.String> getVariableNameSet()
        Description copied from interface: VariableMap
        Get the set of the variables stored in the variable map so that the caller can iterate through the variables.
        Specified by:
        getVariableNameSet in interface VariableMap
        Returns:
        return value

      • setCaseSensitive

        public void setCaseSensitive()
        Tell the object that the variable names are handled in a case sensitive way. It means that the variables 'vaRIable' and 'variABLE' are two different variables and can live in the global or the actual local variable name space along with each other in peace.

        It is not recommended to use this mode, however most modern programming languages do this.

      • setCaseFreak

        public void setCaseFreak()
        Tell the object that the variable names has to be cased only one way. It means that there can not be a variable named "vaRIable' and 'variABLE' at the same time.

        It is the recommended behavior, however BASIC implementations rarely exhibit such variable name handling this is not the default.

      • setCaseIgnorant

        public void setCaseIgnorant()
        Tell the object that the variable handling is case insensitive. It means that the variables 'vaRIable' and 'variABLE' denote the same variable.

        It is not recommended to use this mode, however most BASIC implementation do this. This is the default behavior.

      • converted

        protected java.lang.String converted​(java.lang.String name)
        Converts the name of a variable in a way that if the name 'a' and name 'b' results the same string converted then 'a' and 'b' are treated from some aspects as the same variable name. The generic approach is simply upper casing.
        Parameters:
        name - parameter
        Returns:
        return value