org.apache.avro.io.parsing
Class Parser

java.lang.Object
  org.apache.avro.io.parsing.Parser

Direct Known Subclasses:

SkipParser

public class Parser
extends Object

Parser is the class that maintains the stack for parsing. This class is used by encoders, which are not required to skip.

Nested Class Summary

static interface

Parser.ActionHandler The parser knows how to handle the terminal and non-terminal symbols.

Field Summary

protected int	pos
protected Symbol[]	stack
protected Parser.ActionHandler	symbolHandler

Constructor Summary

Parser(Symbol root, Parser.ActionHandler symbolHandler)

Method Summary

Symbol	advance(Symbol input) Recursively replaces the symbol at the top of the stack with its production, until the top is a terminal.
int	depth() Returns the depth of the stack.
Symbol	popSymbol() Pops and returns the top symbol from the stack.
void	processImplicitActions() Performs any implicit actions at the top the stack, expanding any production (other than the root) that may be encountered.
void	processTrailingImplicitActions() Performs any "trailing" implicit actions at the top the stack.
void	pushProduction(Symbol sym) Pushes the production for the given symbol sym.
void	pushSymbol(Symbol sym) Pushes sym on to the stack.
void	reset()
Symbol	topSymbol() Returns the top symbol from the stack.

Methods inherited from class java.lang.Object

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

Field Detail

symbolHandler

protected final Parser.ActionHandler symbolHandler

stack

protected Symbol[] stack

pos

protected int pos

Constructor Detail

Parser

public Parser(Symbol root,
              Parser.ActionHandler symbolHandler)
       throws IOException

Throws:

IOException

Method Detail

advance

public final Symbol advance(Symbol input)
                     throws IOException

Recursively replaces the symbol at the top of the stack with its production, until the top is a terminal. Then checks if the top symbol matches the terminal symbol suppled terminal.

Parameters:

input - The symbol to match against the terminal at the top of the stack.

Returns:

The terminal symbol at the top of the stack unless an implicit action resulted in another symbol, in which case that symbol is returned.

Throws:

IOException

processImplicitActions

public final void processImplicitActions()
                                  throws IOException

Performs any implicit actions at the top the stack, expanding any production (other than the root) that may be encountered. This method will fail if there are any repeaters on the stack.

Throws:

IOException

processTrailingImplicitActions

public final void processTrailingImplicitActions()
                                          throws IOException

Performs any "trailing" implicit actions at the top the stack.

Throws:

IOException

pushProduction

public final void pushProduction(Symbol sym)

Pushes the production for the given symbol sym. If sym is a repeater and input is either Symbol.ARRAY_END or Symbol.MAP_END pushes nothing.

Parameters:

sym -

popSymbol

public Symbol popSymbol()

Pops and returns the top symbol from the stack.

topSymbol

public Symbol topSymbol()

Returns the top symbol from the stack.

pushSymbol

public void pushSymbol(Symbol sym)

Pushes sym on to the stack.

depth

public int depth()

Returns the depth of the stack.

reset

public void reset()