org.apache.avro.io.parsing

Class Symbol

java.lang.Object

org.apache.avro.io.parsing.Symbol

Direct Known Subclasses:

Symbol.Alternative, Symbol.ImplicitAction, Symbol.IntCheckAction, Symbol.Repeater, Symbol.Root, Symbol.Sequence

public abstract class Symbol
extends Object

Symbol is the base of all symbols (terminals and non-terminals) of the grammar.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
static class	Symbol.Alternative
static class	Symbol.DefaultStartAction
static class	Symbol.EnumAdjustAction
static class	Symbol.EnumLabelsAction
static class	Symbol.ErrorAction
static class	Symbol.FieldAdjustAction
static class	Symbol.FieldOrderAction
static class	Symbol.ImplicitAction
static class	Symbol.IntCheckAction
static class	Symbol.Kind
static class	Symbol.Repeater
static class	Symbol.ResolvingAction
protected static class	Symbol.Root
protected static class	Symbol.Sequence
static class	Symbol.SkipAction
static class	Symbol.UnionAdjustAction
static class	Symbol.WriterUnionAction

Field Summary

Fields

Modifier and Type	Field and Description
static Symbol	ARRAY_END
static Symbol	ARRAY_START
static Symbol	BOOLEAN
static Symbol	BYTES
static Symbol	DEFAULT_END_ACTION
static Symbol	DOUBLE
static Symbol	ENUM
static Symbol	FIELD_ACTION
static Symbol	FIELD_END
static Symbol	FIXED
static Symbol	FLOAT
static Symbol	INT
static Symbol	ITEM_END
Symbol.Kind	kind
static Symbol	LONG
static Symbol	MAP_END
static Symbol	MAP_KEY_MARKER
static Symbol	MAP_START
static Symbol	NULL The terminal symbols for the grammar.
Symbol[]	production The production for this symbol.
static Symbol	RECORD_END
static Symbol	RECORD_START
static Symbol	STRING
static Symbol	UNION
static Symbol	UNION_END
static Symbol	WRITER_UNION_ACTION

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	Symbol(Symbol.Kind kind) Constructs a new symbol of the given kind kind.
protected	Symbol(Symbol.Kind kind, Symbol[] production)

Method Summary

Modifier and Type	Method and Description
static Symbol.DefaultStartAction	defaultStartAction(byte[] contents)
static Symbol.EnumAdjustAction	enumAdjustAction(int rsymCount, Object[] adj)
static Symbol.EnumLabelsAction	enumLabelsAction(List<String> symbols) For JSON.
static Symbol.FieldAdjustAction	fieldAdjustAction(int rindex, String fname, Set<String> aliases)
static Symbol.FieldOrderAction	fieldOrderAction(Schema.Field[] fields)
Symbol	flatten(Map<Symbol.Sequence,Symbol.Sequence> map, Map<Symbol.Sequence,List<org.apache.avro.io.parsing.Symbol.Fixup>> map2)
int	flattenedSize()
protected static int	flattenedSize(Symbol[] symbols, int start) Returns the amount of space required to flatten the given sub-array of symbols.
static boolean	hasErrors(Symbol symbol) Returns true if the Parser contains any Error symbol, indicating that it may fail for some inputs.
static Symbol.IntCheckAction	intCheckAction(int size)
static Symbol.SkipAction	skipAction(Symbol symToSkip)
static Symbol.UnionAdjustAction	unionAdjustAction(int rindex, Symbol sym)
static Symbol.WriterUnionAction	writerUnionAction()

Methods inherited from class java.lang.Object

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

Field Detail

kind

public final Symbol.Kind kind

production

public final Symbol[] production

The production for this symbol. If this symbol is a terminal this is null. Otherwise this holds the the sequence of the symbols that forms the production for this symbol. The sequence is in the reverse order of production. This is useful for easy copying onto parsing stack. Please note that this is a final. So the production for a symbol should be known before that symbol is constructed. This requirement cannot be met for those symbols which are recursive (e.g. a record that holds union a branch of which is the record itself). To resolve this problem, we initialize the symbol with an array of nulls. Later we fill the symbols. Not clean, but works. The other option is to not have this field a final. But keeping it final and thus keeping symbol immutable gives some comfort. See various generators how we generate records.

NULL

public static final Symbol NULL

The terminal symbols for the grammar.

BOOLEAN

public static final Symbol BOOLEAN

INT

public static final Symbol INT

LONG

public static final Symbol LONG

FLOAT

public static final Symbol FLOAT

DOUBLE

public static final Symbol DOUBLE

STRING

public static final Symbol STRING

BYTES

public static final Symbol BYTES

FIXED

public static final Symbol FIXED

ENUM

public static final Symbol ENUM

UNION

public static final Symbol UNION

ARRAY_START

public static final Symbol ARRAY_START

ARRAY_END

public static final Symbol ARRAY_END

MAP_START

public static final Symbol MAP_START

MAP_END

public static final Symbol MAP_END

ITEM_END

public static final Symbol ITEM_END

WRITER_UNION_ACTION

public static final Symbol WRITER_UNION_ACTION

FIELD_ACTION

public static final Symbol FIELD_ACTION

RECORD_START

public static final Symbol RECORD_START

RECORD_END

public static final Symbol RECORD_END

UNION_END

public static final Symbol UNION_END

FIELD_END

public static final Symbol FIELD_END

DEFAULT_END_ACTION

public static final Symbol DEFAULT_END_ACTION

MAP_KEY_MARKER

public static final Symbol MAP_KEY_MARKER

Constructor Detail

Symbol

protected Symbol(Symbol.Kind kind)

Constructs a new symbol of the given kind kind.

Symbol

protected Symbol(Symbol.Kind kind,
                 Symbol[] production)

Method Detail

flatten

public Symbol flatten(Map<Symbol.Sequence,Symbol.Sequence> map,
                      Map<Symbol.Sequence,List<org.apache.avro.io.parsing.Symbol.Fixup>> map2)

flattenedSize

public int flattenedSize()

flattenedSize

protected static int flattenedSize(Symbol[] symbols,
                                   int start)

Returns the amount of space required to flatten the given sub-array of symbols.

Parameters:

symbols - The array of input symbols.

start - The index where the subarray starts.

Returns:

The number of symbols that will be produced if one expands the given input.

hasErrors

public static boolean hasErrors(Symbol symbol)

Returns true if the Parser contains any Error symbol, indicating that it may fail for some inputs.

intCheckAction

public static Symbol.IntCheckAction intCheckAction(int size)

enumAdjustAction

public static Symbol.EnumAdjustAction enumAdjustAction(int rsymCount,
                                                       Object[] adj)

writerUnionAction

public static Symbol.WriterUnionAction writerUnionAction()

skipAction

public static Symbol.SkipAction skipAction(Symbol symToSkip)

fieldAdjustAction

public static Symbol.FieldAdjustAction fieldAdjustAction(int rindex,
                                                         String fname,
                                                         Set<String> aliases)

fieldOrderAction

public static Symbol.FieldOrderAction fieldOrderAction(Schema.Field[] fields)

defaultStartAction

public static Symbol.DefaultStartAction defaultStartAction(byte[] contents)

unionAdjustAction

public static Symbol.UnionAdjustAction unionAdjustAction(int rindex,
                                                         Symbol sym)

enumLabelsAction

public static Symbol.EnumLabelsAction enumLabelsAction(List<String> symbols)

For JSON.