org.gjt.sp.jedit.bsh

## Class CallStack

- java.lang.Object
- - org.gjt.sp.jedit.bsh.CallStack

    public class CallStack
    extends java.lang.Object

A stack of NameSpaces representing the call path. Each method invocation, for example, pushes a new NameSpace onto the stack. The top of the stack is always the current namespace of evaluation.

This is used to support the this.caller magic reference and to print script "stack traces" when evaluation errors occur.

Note: it would be awefully nice to use the java.util.Stack here. Sigh... have to stay 1.1 compatible.

Note: How can this be thread safe, you might ask? Wouldn't a thread executing various beanshell methods be mutating the callstack? Don't we need one CallStack per Thread in the interpreter? The answer is that we do. Any java.lang.Thread enters our script via an external (hard) Java reference via a This type interface, e.g. the Runnable interface implemented by This or an arbitrary interface implemented by XThis. In that case the This invokeMethod() method (called by any interface that it exposes) creates a new CallStack for each external call.

### Constructor Summary

Constructors
Constructor and Description
`CallStack()`
`CallStack(NameSpace namespace)`

### Method Summary

Methods
`void` `clear()`
`CallStack` `copy()` Occasionally we need to freeze the callstack for error reporting purposes, etc.
`int` `depth()`
`NameSpace` `get(int depth)` zero based.
`NameSpace` `pop()`
`void` `push(NameSpace ns)`
`void` `set(int depth, NameSpace ns)` This is kind of crazy, but used by the setNameSpace command.
`NameSpace` `swap(NameSpace newTop)` Swap in the value as the new top of the stack and return the old value.
`NameSpace[]` `toArray()`
`NameSpace` `top()`
`java.lang.String` `toString()`

### Methods inherited from class java.lang.Object

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

### Constructor Detail

#### CallStack

    public CallStack()

#### CallStack

    public CallStack(NameSpace namespace)

### Method Detail

#### clear

    public void clear()

#### push

    public void push(NameSpace ns)

#### top

    public NameSpace top()

#### get

    public NameSpace get(int depth)

zero based.

#### set

    public void set(int depth,
           NameSpace ns)

This is kind of crazy, but used by the setNameSpace command. zero based.

#### pop

    public NameSpace pop()

#### swap

    public NameSpace swap(NameSpace newTop)

Swap in the value as the new top of the stack and return the old value.

#### depth

    public int depth()

#### toArray

    public NameSpace[] toArray()

#### toString

    public java.lang.String toString()

Overrides:
  `toString` in class `java.lang.Object`

#### copy

    public CallStack copy()

Occasionally we need to freeze the callstack for error reporting purposes, etc.