condor.classad
Class AttrRef

java.lang.Object
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  +--condor.classad.Expr
        |
        +--condor.classad.AttrRef

public class AttrRef

extends Expr

A reference to another attribute. A leaf node in an expression tree that represents an attribute reference. It includes a ``locality'' (one of SELF, PARENT, SUPER, or ROOT) and an optional pointer to a target RecordExpr. The target is set at compile time by a post-pass over the expression tree as follows

SELF

The target is smallest enclosing RecordExpr. The concrete syntax "xxx" is compiled as SELF.xxx (i.e., Select(AttrReff(SELF),"xxx")).

ROOT

The target is the largest enclosing RecordExpr. The concrete syntax ".xxx" is compiled as ROOT.xxx.

PARENT

The target is the second smallest enclosing RecordExpr. In other words, the smallest RecordExpr properly enclosing the RecordExpr denoted by SELF.

SUPER

If the SELF RecordExpr does not have any attribute named "super", the target is the same as PARENT; else if the super attribute of the SELF RecordExpr is an AttrRef, the target is the same as the target of that AttrRef; otherwise, it is null.

The target is null if the indicated RecordExpr does not exist. In particular, for SELF and ROOT, the target is null if this AttrRef is not nested inside any RecordExpr. For PARENT, it is null if it is not nested at least two deep inside RecordExprs. If the target is null, it is dynamically supplied at evaluation time from an associated Context.

Version:

1.2

Author:

Marvin Solomon

See Also:

Expr, RecordExpr, Context

Fields inherited from class condor.classad.Expr

ABSOLUTE_TIME, AND, ATTRIBUTE, BIT_COMPLEMENT, BITAND, BITOR, BITXOR, BOOLEAN, BRIEF, CALL, COMPACT, COND, dblevel, DIFFERENT, DIV, EQUAL, ERROR, formatFlags, formatIndent, GREATER, GREATER_EQ, INTEGER, LEFT_SHIFT, LESS, LESS_EQ, LIST, MAXPREC, MINIMAL_PARENTHESES, MINUS, MOD, MULTI_LINE_ADS, MULTI_LINE_LISTS, NO_ESCAPE_STRINGS, NOT, NOT_EQUAL, OP, opName, OR, PLUS, READABLE, REAL, RECORD, RELATIVE_TIME, RIGHT_SHIFT, SAME, SELECTION, SHOW_ERROR_DETAIL, SHOW_INSTANCES, STRING, SUBSCRIPT, TIMES, type, UMINUS, UNDEFINED, UPLUS, URIGHT_SHIFT

Constructor Summary

AttrRef(int locality)
Create a new AttrRef.

Method Summary

protected int	prec() The precedence of this expression
protected Expr	reEval(Context ctx) Evalutate this expression.
String	toString() Convert this Expr to a string.

Methods inherited from class condor.classad.Expr

db, db, disableFormatFlags, enableFormatFlags, eval, getFormatFlags, isConstant, isNormalForm, mark, mark, mark, select, setFormatFlags, toString, typeName

Methods inherited from class java.lang.Object

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

Constructor Detail

AttrRef

public AttrRef(int locality)

Create a new AttrRef.

Parameters:

locality - one of SELF, ROOT, PARENT, or SUPER.

Method Detail

toString

public String toString()

Convert this Expr to a string. The exact format of the result is controled by the static fields Expr.formatFlags and Expr.formatIndent. The result may be multiple lines long (it may include embedded newlines and tabs), but it never ends with a newline.

Overrides:

toString in class Expr

Returns:

a string representation of the this Context

See Also:

Expr.formatFlags, Expr.formatIndent

reEval

protected Expr reEval(Context ctx)

Evalutate this expression.

Overrides:

reEval in class Expr

Parameters:

ctx - an evaluation context for evaluating this expression

Returns:

a Constant, ListExpr, or RecordExpr representing the value.

See Also:

Expr.eval(condor.classad.Context)

prec

protected int prec()

The precedence of this expression

Overrides:

prec in class Expr

Returns:

the precendence of this node (MAXPREC).