Module com.darkcollective.relix.value

Package com.darkcollective.relix.value

Interface Value

All Known Implementing Classes:

ArrayValue, BooleanValue, DateValue, DurationValue, NullValue, NumberValue, StringValue, StructValue, TimestampValue, TimeValue

public sealed interface Value
permits StringValue, NumberValue, BooleanValue, NullValue, StructValue, ArrayValue, DateValue, TimeValue, TimestampValue, DurationValue

A runtime scalar value produced or consumed during query execution.

The sealed hierarchy maps directly onto the type lattice in ScalarType:

• StringValue — STRING
• NumberValue — NUMBER
• BooleanValue — BOOLEAN
• NullValue — absent value, compatible with all types
• StructValue — a nested object; reports ScalarType.ANY
• ArrayValue — a nested array; reports ScalarType.ANY
• DateValue — DATE (a LocalDate)
• TimeValue — TIME (a LocalTime)
• TimestampValue — TIMESTAMP (a UTC Instant)
• DurationValue — DURATION (a Duration)

Pattern matching over the sealed subtypes is the preferred way to dispatch on value kind:

 String display = switch (value) {
     case StringValue  s -> s.value();
     case NumberValue  n -> n.value().toPlainString();
     case BooleanValue b -> String.valueOf(b.value());
     case NullValue    n -> "NULL";
     default           -> value.asDisplayString();
 };
 

A switch that names every subtype needs no default and will not compile once a new one is added — which is the point of sealing the hierarchy.

Method Summary

Modifier and Type	Method	Description
String	asDisplayString()	Returns a human-readable display string for this value, suitable for output formatting.
boolean	isNull()	Returns true if this value is null (absent).
ScalarType	type()	Returns the ScalarType that describes this value's kind.

Method Details

isNull

boolean isNull()

Returns true if this value is null (absent).

Returns:

whether this is a NullValue

type

ScalarType type()

Returns the ScalarType that describes this value's kind. NullValue returns ScalarType.ANY.

Returns:

the scalar type

asDisplayString

String asDisplayString()

Returns a human-readable display string for this value, suitable for output formatting. NullValue returns "NULL".

Returns:

display string; never null