edu.cmu.cs.cs214.hw5.core

Interface ColumnSpecification

All Known Implementing Classes:

AbstractColumn, IntegerColumn, NumericColumn, PolygonColumn, StringColumn

public interface ColumnSpecification

A column specification is a description of a type of column that adheres to a given format.

Method Summary

Modifier and Type	Method and Description
java.lang.Object	extract(Column column, int index) Convert the given cell in the column to a structured format.
java.lang.String	getName() Get a human-readable name of this column.
java.lang.String	getTypeName() Get a human-readable name of this type of column specification.
boolean	isValid(Column column) Determine whether the given column represents a valid instance of this column specification.

Method Detail

getName

java.lang.String getName()

Get a human-readable name of this column. This should describe a particular instance of the column, like "Radius", not the abstract type, like "Numeric column". (Use getTypeName() for that.)

Returns:

a name for this column

getTypeName

java.lang.String getTypeName()

Get a human-readable name of this type of column specification. For example, "Numeric column".

Returns:

a name for this column specification

isValid

boolean isValid(Column column)
         throws java.lang.NullPointerException

Determine whether the given column represents a valid instance of this column specification.

Parameters:

column - the column to check

Returns:

true if the given column is valid, or false if it is not

Throws:

java.lang.NullPointerException - if column == null

extract

java.lang.Object extract(Column column,
                         int index)
                  throws java.lang.IndexOutOfBoundsException

Convert the given cell in the column to a structured format. The format depends on the implementation of the column specification; implementations are encouraged to covariantly narrow the return type. (For example, a numeric column specification might override this method to return a Number.)

If this is called on a column that would not validate under isValid(Column), then the results are undefined.

Parameters:

column - the column containing the cell to extract

index - the index into column of the cell to extract

Returns:

the structured representation of the cell

Throws:

java.lang.IndexOutOfBoundsException - if index is out of the range of column