com.healthmarketscience.jackcess.expr

Interface Expression

public interface Expression

An Expression is an executable handle to an Access expression. While the expression framework is implemented separately from the core database functionality, most usage of Expressions will happen indirectly within the context of normal database operations. Thus, most users will not ever directly interact with an Expression instance. That said, Expressions may be executed independently of a Database instance if desired.

Author:

James Ahlborn

Method Summary

Modifier and Type	Method and Description
void	collectIdentifiers(Collection<Identifier> identifiers) Adds any Identifiers from this expression to the given collection.
Object	eval(EvalContext ctx) Evaluates the expression and returns the result.
boolean	isConstant()
String	toCleanString(LocaleContext ctx)
String	toDebugString(LocaleContext ctx)
String	toRawString()

Method Detail

eval

Object eval(EvalContext ctx)

Evaluates the expression and returns the result.

Parameters:

ctx - the context within which to evaluate the expression

Returns:

the result of the expression evaluation

toDebugString

String toDebugString(LocaleContext ctx)

Returns:

a detailed string which indicates how the expression was interpreted by the expression evaluation engine.

toCleanString

String toCleanString(LocaleContext ctx)

Returns:

a parsed and re-formated version of the expression. This may look slightly different than the original, raw string, although it should be an equivalent expression.

toRawString

String toRawString()

Returns:

the original, unparsed expression string. This is the same as the value which will be returned by Object.toString().

isConstant

boolean isConstant()

Returns:

true if this is a constant expression. A constant expression will always return the same result when invoked and has no side effect.

collectIdentifiers

void collectIdentifiers(Collection<Identifier> identifiers)

Adds any Identifiers from this expression to the given collection.