Package uk.ac.starlink.table
Interface Domain<M extends DomainMapper>
- All Known Implementing Classes:
TimeDomain
public interface Domain<M extends DomainMapper>
Common value domain. An instance of this class represents some
class of externally representable values that can in some sense
be treated internally in the same way, but which may have
various different external representations.
It is used in conjunction with instances of the
DomainMapper
interface, provided by the table input handler or the user,
to untangle different possible representations of physical values
in input data.
See the available instances of this interface such as
TimeDomain
for better understanding of how it works.
- Since:
- 14 Apr 2020
- Author:
- Mark Taylor
- See Also:
-
Method Summary
Modifier and TypeMethodDescriptionReturns the name of this domain.M[]
Returns a list of all mappers known to map values to this domain.getPossibleMapper
(ValueInfo info) Returns a typed DomainMapper that can be used for data described by the given metadata object.getProbableMapper
(ValueInfo info) Returns a typed DomainMapper that is likely to be appropriate for data described by the given metadata object.
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Method Details
-
getDomainName
String getDomainName()Returns the name of this domain.- Returns:
- domain name
-
getMappers
M[] getMappers()Returns a list of all mappers known to map values to this domain. This is not necessarily exhaustive, and may in particular not include mappers specific to certain input file formats, but it can be offered to users as a list of options for mapping to this domain where no other option is obvious.- Returns:
- list of generic mappers to this domain
-
getProbableMapper
Returns a typed DomainMapper that is likely to be appropriate for data described by the given metadata object.In general, implementations of this method will first check the
ValueInfo.getDomainMappers()
method. If it is doubtful how to map from the given info to this domain, null should be returned.- Parameters:
info
- metadata describing data to be mapped- Returns:
- reliable guess at a suitable mapper
-
getPossibleMapper
Returns a typed DomainMapper that can be used for data described by the given metadata object. If some reasonable way to make the conversion exists, an appropriate value should be returned, but it's quite possible the conversion will be incorrect. If there is no known possible or plausible mapper, null should be returned.If the result of
getProbableMapper(uk.ac.starlink.table.ValueInfo)
is non-null, then this method must also return non-null, but this method is not required to return the same value asgetProbableMapper
.- Parameters:
info
- metadata describing data to be mapped- Returns:
- best-efforts guess at a suitable mapper
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