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
    Modifier and Type | Method and Description
    --- | ---
    `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.