Package org.openrefine.grel.ast

Class FunctionCallExpr

java.lang.Object

org.openrefine.grel.ast.FunctionCallExpr

All Implemented Interfaces:

Serializable, GrelExpr

Direct Known Subclasses:

ArrayExpr

public class FunctionCallExpr
extends Object
implements GrelExpr

An abstract syntax tree node encapsulating a function call. The function's arguments are all evaluated down to values before the function is applied. If any argument is an error, the function is not applied, and the error is the result of the expression.

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field	Description
protected GrelExpr[]	_args
protected Function	_function
protected String	_sourceName

Constructor Summary

Constructors

Constructor	Description
FunctionCallExpr(GrelExpr[] args, Function f, String sourceName)

Method Summary

Modifier and Type	Method	Description
boolean	equals(Object other)
Object	evaluate(Properties bindings)	Returns the value of the expression in a given context.
Set<String>	getColumnDependencies(String baseColumn)	Returns the names of the columns this expression depends on.
boolean	isLocal()
FunctionCallExpr	renameColumnDependencies(Map<String,String> substitutions)	Translates this expression by simultaneously substituting column names as the supplied map specifies.
String	toString()	For GREL expressions, toString should return the source code of the expression, or a source code for an equivalent expression.

Methods inherited from class java.lang.Object

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

Field Detail

_function

protected final Function _function

_args

protected final GrelExpr[] _args

_sourceName

protected final String _sourceName

Constructor Detail

FunctionCallExpr

public FunctionCallExpr(GrelExpr[] args,
                        Function f,
                        String sourceName)

Method Detail

evaluate

public Object evaluate(Properties bindings)

Description copied from interface: GrelExpr

Returns the value of the expression in a given context.

Specified by:

evaluate in interface GrelExpr

Parameters:

bindings - the evaluation context, mapping variable names to their values

Returns:

the result of the evaluation of the expression

toString

public String toString()

Description copied from interface: GrelExpr

For GREL expressions, toString should return the source code of the expression, or a source code for an equivalent expression. (without the "grel:" prefix).

Specified by:

toString in interface GrelExpr

Overrides:

toString in class Object

equals

public boolean equals(Object other)

Overrides:

equals in class Object

getColumnDependencies

public final Set<String> getColumnDependencies(String baseColumn)

Description copied from interface: GrelExpr

Returns the names of the columns this expression depends on.

Specified by:

getColumnDependencies in interface GrelExpr

Parameters:

baseColumn - the name of the column this expression is based on (null if none)

Returns:

null if the columns could not be isolated: in this case, the expression might depend on all columns in the project.

renameColumnDependencies

public FunctionCallExpr renameColumnDependencies(Map<String,String> substitutions)

Description copied from interface: GrelExpr

Translates this expression by simultaneously substituting column names as the supplied map specifies.

This is only possible if the extraction of column dependencies with GrelExpr.getColumnDependencies(String) succeeds (return a non-null value).

Specified by:

renameColumnDependencies in interface GrelExpr

Parameters:

substitutions - a map specifying new names for some columns. If a column name is not present in the map, it is assumed that the column is not renamed.

Returns:

a new expression with updated column names.

isLocal

public boolean isLocal()

Specified by:

isLocal in interface GrelExpr

Returns:

true when the expression can be evaluated purely based on the local context (see Evaluable).