edu.cmu.cs.cs214.hw5.columns

Class AbstractColumn<E>

java.lang.Object

edu.cmu.cs.cs214.hw5.columns.AbstractColumn<E>

Type Parameters:

E - the type of element stored in this kind of column

All Implemented Interfaces:

ColumnSpecification

Direct Known Subclasses:

IntegerColumn, NumericColumn, PolygonColumn, StringColumn

public abstract class AbstractColumn<E>
extends java.lang.Object
implements ColumnSpecification

A column specification that transforms each cell individually, expecting each cell to follow a common format and declaring a column invalid if any cell does not satisfy this requirement. This abstraction can be applied to any homogeneous column: if you can say "this column holds widgets," then you can use an AbstractColumn<Widget>.

Constructor Summary

Constructors

Constructor and Description
AbstractColumn(java.lang.String name) Create a new column with the given name.

Method Summary

Modifier and Type	Method and Description
E	extract(Column column, int index) Convert the given cell in the column to a structured format.
java.util.List<E>	extractAll(Column column) Like calling extract(Column, int) on each cell in a column.
java.util.List<E>	extractAllFrom(java.util.Map<? extends ColumnSpecification,? extends Column> columnMap) Get all the data associated with this column in the given map.
java.lang.String	getName() Get a human-readable name of this column.
boolean	isValid(Column column) Determine whether the given column represents a valid instance of this column specification.
protected abstract java.util.Optional<E>	parse(java.lang.String s) Attempt to parse the given string into the format expected by this kind of column, returning Optional.empty() on failure.

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.cmu.cs.cs214.hw5.core.ColumnSpecification

getTypeName

Constructor Detail

AbstractColumn

public AbstractColumn(java.lang.String name)

Create a new column with the given name.

Parameters:

name - the name of this column, like "Pizza consumption"

Method Detail

getName

public java.lang.String getName()

Description copied from interface: ColumnSpecification

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 ColumnSpecification.getTypeName() for that.)

Specified by:

getName in interface ColumnSpecification

Returns:

a name for this column

parse

protected abstract java.util.Optional<E> parse(java.lang.String s)

Attempt to parse the given string into the format expected by this kind of column, returning Optional.empty() on failure.

Parameters:

s - a string representing an entry in a column, which may or may not be valid

Returns:

an Optional of the correctly parsed value, or Optional.empty() if the given string is not valid; this must not be null

isValid

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

Description copied from interface: ColumnSpecification

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

Specified by:

isValid in interface ColumnSpecification

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

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

Description copied from interface: ColumnSpecification

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 ColumnSpecification.isValid(Column), then the results are undefined.

Specified by:

extract in interface ColumnSpecification

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

extractAll

public java.util.List<E> extractAll(Column column)

Like calling extract(Column, int) on each cell in a column.

Convert all the cells 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 List<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

Returns:

a newly allocated mutable list containing all the cells in this column (in structured form, as with extract(Column, int))

extractAllFrom

public java.util.List<E> extractAllFrom(java.util.Map<? extends ColumnSpecification,? extends Column> columnMap)

Get all the data associated with this column in the given map. The map probably comes from someSeries.data(), and you want to actually get the data associated with this column. This method will do that.

More precisely: given a map of column specifications to columns that includes this column specification as a key, get the column associated with this column and call extractAll(Column) on it.

If the column would not validate under isValid(Column), then the results are undefined.

Parameters:

columnMap - the map of column specifications to columns that maps this column specification to some column of data

Returns:

a newly allocated mutable list containing all the cells in the relevant column (in structured form, as with extract(Column, int))

Throws:

java.lang.IllegalArgumentException - if this is not a key in columnMap, or if the column on the other side is null