de.unkrig.commons.text.scanner

Class StatefulScanner<TT extends java.lang.Enum<TT>,S extends java.lang.Enum<S>>

java.lang.Object

de.unkrig.commons.text.scanner.AbstractScanner<TT>

de.unkrig.commons.text.scanner.StatefulScanner<TT,S>

Type Parameters:

TT - Enumerates the scanner-specific token types

S - Enumerates the scanner-specific non-default states

All Implemented Interfaces:

ProducerWhichThrows<AbstractScanner.Token<TT>,ScanException>, StringScanner<TT>

public class StatefulScanner<TT extends java.lang.Enum<TT>,S extends java.lang.Enum<S>>
extends AbstractScanner<TT>

A scanner that produces Tokens from a character stream.

Before produce() is called, the scanner must be configured by invoking its addRule(String, Enum) methods. These define how character sequences are converted into AbstractScanner.Tokens, and also how the scanner changes state. Initially the scanner is in the default state.

The non-default states are defined by the S type parameter.

For an example usage, see JavaScanner.

Nested Class Summary

Nested classes/interfaces inherited from class de.unkrig.commons.text.scanner.AbstractScanner

AbstractScanner.Token<TT extends java.lang.Enum<TT>>

Field Summary

Fields inherited from class de.unkrig.commons.text.scanner.AbstractScanner

cs, offset, previousTokenOffset

Constructor Summary

Constructors

Constructor and Description
StatefulScanner(java.lang.Class<S> states)

Method Summary

Modifier and Type	Method and Description
void	addRule(S state, java.lang.String regex, TT tokenType) Adds a rule that applies iff the scanner is in the the given state.
void	addRule(S state, java.lang.String regex, TT tokenType, S nextState) Adds a rule that applies iff the scanner is in the the given state.
void	addRule(java.lang.String regex, TT tokenType) Adds a rule that applies iff the scanner is in the "default state".
void	addRule(java.lang.String regex, TT tokenType, S nextState) Adds a rule that applies iff the scanner is in the "default state".
AbstractScanner.Token<TT>	produce() Before StringScanner.setInput(CharSequence) is called, this method returns null.

Methods inherited from class de.unkrig.commons.text.scanner.AbstractScanner

getOffset, getPreviousTokenOffset, setInput, toString

Methods inherited from class java.lang.Object

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

Constructor Detail

StatefulScanner

public StatefulScanner(java.lang.Class<S> states)

Method Detail

addRule

public void addRule(java.lang.String regex,
                    TT tokenType)

Adds a rule that applies iff the scanner is in the "default state". After the rule has matched, the scanner remains in the default state.

See Also:

Pattern

addRule

public void addRule(java.lang.String regex,
                    TT tokenType,
                    S nextState)

Adds a rule that applies iff the scanner is in the "default state".

Parameters:

nextState - The new current state after the rule has matched

See Also:

Pattern

addRule

public void addRule(@Nullable
                    S state,
                    java.lang.String regex,
                    TT tokenType)

Adds a rule that applies iff the scanner is in the the given state. The scanner returns to the default state after the rule has matched.

Parameters:

state - null means "any state"

See Also:

Pattern

addRule

public void addRule(@Nullable
                    S state,
                    java.lang.String regex,
                    TT tokenType,
                    S nextState)

Adds a rule that applies iff the scanner is in the the given state.

Parameters:

state - null means "any state"

nextState - The new current state after the rule has matched

See Also:

Pattern

produce

@Nullable
public AbstractScanner.Token<TT> produce()
                                             throws ScanException

Description copied from interface: StringScanner

Before StringScanner.setInput(CharSequence) is called, this method returns null. After StringScanner.setInput(CharSequence) was called, this method breaks the input char character sequence up into tokens and returns them one by one. When the input char sequence is exhausted, null is returned until StringScanner.setInput(CharSequence) is called again.

Returns:

null iff the input string is exhausted

Throws:

ScanException