TopcatJELRowReader (Starjava TOPCAT API)

java.lang.Object
- gnu.jel.DVMap
- - uk.ac.starlink.ttools.jel.JELRowReader
  - - uk.ac.starlink.ttools.jel.StarTableJELRowReader
    - - uk.ac.starlink.ttools.jel.RandomJELRowReader
      - uk.ac.starlink.topcat.TopcatJELRowReader

```
public class TopcatJELRowReader
extends uk.ac.starlink.ttools.jel.RandomJELRowReader
```
Random JELRowReader which in addition to the variables recognised by the superclass, also recognises named row subsets (RowSubset inclusion flag vectors):

Row Subset _ID identifiers:
The character '_' followed by the 1-based index of a defined row subset returns true iff the current column is part of the subset.
Row Subset names:
The name of a subset (case-insensitive) returns true iff the current column is part of the named subset.

Since:

8 Feb 2005

Author:

Mark Taylor (Starlink)

Field Summary

Fields
Modifier and Type Field Description

static char SUBSET_ID_CHAR
Prefix identifying a unique subset identifier.
- Fields inherited from class uk.ac.starlink.ttools.jel.JELRowReader
  COLUMN_ID_CHAR, NULL_QUERY_PREFIX, OBJECT_PREFIX
- Fields inherited from class uk.ac.starlink.ttools.jel.StarTableJELRowReader
  PARAM_PREFIX, UCD_PREFIX, UTYPE_PREFIX

Fields
Modifier and Type	Field	Description
`static char`	`SUBSET_ID_CHAR`	Prefix identifying a unique subset identifier.

Constructor Summary

Constructors
Constructor	Description
`TopcatJELRowReader(uk.ac.starlink.table.StarTable table, RowSubset[] subsets, int[] subsetIds)`	Constructs a new row reader for a random-access table.

Method Summary

All Methods Instance Methods Concrete Methods
Modifier and Type	Method	Description
`protected uk.ac.starlink.ttools.jel.Constant`	`createDescribedValueConstant(uk.ac.starlink.table.DescribedValue dval)`	Returns a constant which is evaluated at runtime.
`boolean`	`getBooleanProperty(short isub)`	Returns the actual subset value for the current row and a given column.
`java.lang.String`	`getTypeName(java.lang.String name)`	Overrides superclass implementation to recognise row subsets by name or _ID.
`java.lang.Object`	`translate(java.lang.String name)`	Overrides superclass implementation to recognise subsets as well as the other special objects.

Methods inherited from class uk.ac.starlink.ttools.jel.JELRowReader
evaluate, evaluateDouble, foundNull, getBooleanArrayProperty, getBooleanProperty, getBooleanProperty, getBooleanValue, getByteArrayProperty, getByteProperty, getByteValue, getCharArrayProperty, getCharProperty, getCharValue, getColumnIndex, getDateArrayProperty, getDoubleArrayProperty, getDoubleProperty, getDoubleValue, getFloatArrayProperty, getFloatProperty, getFloatValue, getIntArrayProperty, getIntProperty, getIntValue, getLongArrayProperty, getLongProperty, getLongValue, getNumberProperty, getObjectArrayProperty, getObjectProperty, getShortArrayProperty, getShortProperty, getShortValue, getStringArrayProperty, getStringProperty, setFailOnNull, stripPrefix

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from class uk.ac.starlink.ttools.jel.RandomJELRowReader
evaluateAtRow, getCell, getCurrentRow, setCurrentRow

Methods inherited from class uk.ac.starlink.ttools.jel.StarTableJELRowReader
getBooleanColumnValue, getByteColumnValue, getCharColumnValue, getColumnClass, getColumnIndexByName, getConstantByName, getDoubleColumnValue, getFloatColumnValue, getIntColumnValue, getLongColumnValue, getObjectColumnValue, getShortColumnValue, getSpecialByName, getTable, getUcdRegex, getUtypeRegex, isBlank

- Field Detail
  - SUBSET_ID_CHAR
```
public static final char SUBSET_ID_CHAR
```
    Prefix identifying a unique subset identifier.
    
    See Also:
    
    Constant Field Values
- Constructor Detail
  - TopcatJELRowReader
```
public TopcatJELRowReader(uk.ac.starlink.table.StarTable table,
                          RowSubset[] subsets,
                          int[] subsetIds)
```
    Constructs a new row reader for a random-access table.
    
    Parameters:
    
    table - table object
    
    subsets - array of RowSubset objects which this reader will recognise (may be null)
    
    subsetIds - array of integer identifiers by which the subsets array will be identified; must be the same length as subsets
    
    Throws:
    
    java.lang.IllegalArgumentException - if table.isRandom() returns false
- Method Detail
  - getTypeName
```
public java.lang.String getTypeName(java.lang.String name)
```
    Overrides superclass implementation to recognise row subsets by name or _ID.
    
    Overrides:
    
    getTypeName in class uk.ac.starlink.ttools.jel.JELRowReader
    
    Parameters:
    
    name - the variable name
    
    Returns:
    
    corresponding method name fragment
    
    See Also:
    
    "JEL manual"
  - translate
```
public java.lang.Object translate(java.lang.String name)
```
    Overrides superclass implementation to recognise subsets as well as the other special objects. The additional return type is:
    - a Short (the subset index) if the column specification appears to reference a known row subset
    Overrides:
    
    translate in class uk.ac.starlink.ttools.jel.JELRowReader
    
    Parameters:
    
    name - the name of the variable-like object to evaluate
    
    Returns:
    
    a numeric object corresponding to an object which we know how to evaluate
    
    See Also:
    
    "JEL manual"
  - getBooleanProperty
```
public boolean getBooleanProperty(short isub)
```
    Returns the actual subset value for the current row and a given column.
    
    Parameters:
    
    isub - index of the subset to evaluate at the current row
    
    Returns:
    
    result of the isIncluded method of the RowSubset indicated at the current row
  - createDescribedValueConstant
```
protected uk.ac.starlink.ttools.jel.Constant createDescribedValueConstant(uk.ac.starlink.table.DescribedValue dval)
```
    Returns a constant which is evaluated at runtime. This is more appropriate than the inherited (evaluate at call time) behaviour, since within TOPCAT the constant's value may change as a result of user intervention during the lifetime of the returned object.
    
    Overrides:
    
    createDescribedValueConstant in class uk.ac.starlink.ttools.jel.StarTableJELRowReader

Class TopcatJELRowReader

Field Summary

Fields inherited from class uk.ac.starlink.ttools.jel.JELRowReader

Fields inherited from class uk.ac.starlink.ttools.jel.StarTableJELRowReader

Constructor Summary

Method Summary

Methods inherited from class uk.ac.starlink.ttools.jel.JELRowReader

Methods inherited from class java.lang.Object

Methods inherited from class uk.ac.starlink.ttools.jel.RandomJELRowReader

Methods inherited from class uk.ac.starlink.ttools.jel.StarTableJELRowReader

Field Detail

SUBSET_ID_CHAR

Constructor Detail

TopcatJELRowReader

Method Detail

getTypeName

translate

getBooleanProperty

createDescribedValueConstant