NAME

Node - a base class for syntax tree nodes

DESCRIPTION

All PAST and POST nodes subclass from this base type.

Accessor Methods

These methods define the external interface of node objects.

source

Sets or gets the source code string that a particular node was parsed from. (Useful for debugging output.)

    node.'source'($S1)
    $S2 = node.'source'()

pos

Sets or gets the position offset in the original source code file that a particular node was parsed from. (Useful for debugging output.)

    node.'pos'($I1)
    $S2 = node.'pos'()

children

Returns a simple array of the children of a particular node.

    $P1 = node.'children'()

child_iter

Returns an iterator for the children of a node.

    iter = node.'child_iter'()

add_child

Adds one child to the node's list of children. If the list doesn't exist yet, it creates it.

    node.'add_child'($P1)

elements

Check how many elements a node has by calling the elements opcode on it:

    $I1 = elements node

Array interface

The children of a node can be directly accessed using array indexes on the node object.

    $P2 = node[5]
    node[0] = $P1

clone

This method captures a few key elements from an existing node to populate a new node.

    newnode.'clone'(oldnode)

dump

Recursively prints a formatted display of the contents of a node.

    node.'dump'()

Utility Methods

These methods provide functionality for the Node class and its subclasses, but aren't part of the external interface for the class.

DUMPABLE

This method returns a list of attributes that should be displayed in a 'dump' operation. Subclasses can override it to return a different list.

accessor

Provides a generic accessor method that can be used by any subclass. It takes three arguments: the name of the attribute to access, a value for the attribute, and a binary flag that says whether to set the attribute.

    self.'accessor'('attrname', value, setflag)