| java.lang.Object
 fri.patterns.interpreter.parsergenerator.lexer.Consumer
All known Subclasses: fri.patterns.interpreter.parsergenerator.lexer.ConsumerAlternatives,
| Consumer | | class Consumer implements Comparable,Serializable(Code) | | Consuming characters (or bytes) means reading from an input stream as long
as the read characters match the pattern the consumer was built for.
A consumer can be built with a fixed string, a character set, other
character consumers, or a mixed sequence of those. It can be a list of
alternating (parallel) consumers. It can be set repeatable and nullable.
A character consumer succeeds when he could apply all consumers or
patterns/sets stored in its sequence when reading input. It fails and
unreads all characters when one non-nullable consumer in its sequence fails.
author:
(c) 2002, Fritz Ritzberger |
| Inner Class :public static class Reference | |
| Constructor Summary | |
| | Consumer(Rule rule)
Empty consumer knowing its rule. | | | Consumer(String charOrString)
Consumer with some start character or fixed string, without rule. | | protected | Consumer()
Internal constructor needed in LexerBuilder. |
| Method Summary | |
| public void | append(String charOrString)
Append a String or character to sequence. | | public void | append(Reference subConsumer)
Add a character consumer reference. | | public void | append(Consumer subConsumer)
Add a character consumer. | | public void | appendSet(String high)
Add a character set by its high character. | | public int | compareTo(Object o)
Implements Comparable: Sort alternatives by precedence: - getStartVariance(), + getStartLength(), + getFixedLength(). | | public ResultTree | consume(InputText input)
Reads from input. | | protected ResultTree | consumeInternal(InputText input)
Consumes characters from Input and stores it into returned result tree. | | public List | getAlternatives()
Always returns null as this consumer holds no alternatives. | | public int | getFixedLength()
The fixed length ends before the first found character set (like "0..9") or repeatable or nullable consumer. | | protected int | getSomeLength(boolean exploreStartLength, List breakIndicator)
| | public Character | getStartCharacter()
Returns the first character of this consumer, or null if starting with a set. | | public int | getStartLength()
The start length ends before the first found repeatable or nullable consumer (like "chars*"), but not before a character set. | | public int | getStartVariance()
Returns the count of possible start characters. | | public boolean | isNullable()
| | public boolean | isRepeatable()
| | protected void | listToString(List list, StringBuffer sb, String separator, boolean separatorAtFirst)
Converts a list into String, for toString() method. | | boolean | matchesRepeatableRule(Rule rule)
Returns true if the rule of this consumer matches the passed left recursive rule.
E.g. | | Consumer | optimize()
Return contained consumer when having only one and no constraints. | | public boolean | overlaps(Consumer cc)
Returns true if the passed consumer could be concurrent with this. | | public void | resolveConsumerReferences(Map charConsumers, Map doneList)
Resolve all references to real consumers after build. | | public void | setNullable()
| | public void | setRepeatable()
| | public void | setStrategyFactoryMethod(StrategyFactoryMethod strategyFactoryMethod)
Passes the factory for Strategy objects to all contained ConsumerAlternatives. | | public void | subtract(Consumer constraint)
Passed Consumer will constrain every character of this consumer. | | public void | subtract(Reference constraint)
Passed reference will constrain every character of this consumer. | | public String | toString()
String representation of consumer: hashcode, sequence and constraints. | | protected String | toStringBase()
Returns the base string for toString() method. |
| fixedLengthstartLengthvariance | | protected int fixedLengthstartLengthvariance(Code) | | |
| Consumer | | Consumer(Rule rule)(Code) | | Empty consumer knowing its rule. This could become a Lexer toplevel consumer.
|
| Consumer | | Consumer(String charOrString)(Code) | | Consumer with some start character or fixed string, without rule.
|
| Consumer | | protected Consumer()(Code) | | Internal constructor needed in LexerBuilder.
|
| append | | public void append(String charOrString)(Code) | | Append a String or character to sequence.
|
| append | | public void append(Reference subConsumer)(Code) | | Add a character consumer reference.
|
| append | | public void append(Consumer subConsumer)(Code) | | Add a character consumer.
|
| appendSet | | public void appendSet(String high) throws LexerException(Code) | | Add a character set by its high character. Low character is previously appended one.
|
| compareTo | | public int compareTo(Object o)(Code) | | Implements Comparable: Sort alternatives by precedence: - getStartVariance(), + getStartLength(), + getFixedLength().
|
| consume | | public ResultTree consume(InputText input) throws IOException(Code) | | Reads from input. Returns null if input did not match, else a result tree containing the text.
Ensures that a nullable consumer never returns null and a repeatable consumer repeats.
Parameters:
input - Input object where to read from. null if no match, else scanned input as a result tree. |
| consumeInternal | | protected ResultTree consumeInternal(InputText input) throws IOException(Code) | | Consumes characters from Input and stores it into returned result tree.
Returns null if nothing has been consumed.
|
| getAlternatives | | public List getAlternatives()(Code) | | Always returns null as this consumer holds no alternatives.
|
| getFixedLength | | public int getFixedLength()(Code) | | The fixed length ends before the first found character set (like "0..9") or repeatable or nullable consumer.
|
| getSomeLength | | protected int getSomeLength(boolean exploreStartLength, List breakIndicator)(Code) | | |
| getStartCharacter | | public Character getStartCharacter()(Code) | | Returns the first character of this consumer, or null if starting with a set.
|
| getStartLength | | public int getStartLength()(Code) | | The start length ends before the first found repeatable or nullable consumer (like "chars*"), but not before a character set.
|
| getStartVariance | | public int getStartVariance()(Code) | | Returns the count of possible start characters. For fixed start character this is 1.
|
| isNullable | | public boolean isNullable()(Code) | | |
| isRepeatable | | public boolean isRepeatable()(Code) | | |
| listToString | | protected void listToString(List list, StringBuffer sb, String separator, boolean separatorAtFirst)(Code) | | Converts a list into String, for toString() method.
|
| matchesRepeatableRule | | boolean matchesRepeatableRule(Rule rule)(Code) | | Returns true if the rule of this consumer matches the passed left recursive rule.
E.g. passing "nonterm ::= nonterm something" would match "nonterm ::= something".
|
| optimize | | Consumer optimize()(Code) | | Return contained consumer when having only one and no constraints. This is called immediately after construction.
|
| overlaps | | public boolean overlaps(Consumer cc)(Code) | | Returns true if the passed consumer could be concurrent with this.
This method does not consider constraints, as these could be complex.
|
| resolveConsumerReferences | | public void resolveConsumerReferences(Map charConsumers, Map doneList) throws LexerException(Code) | | Resolve all references to real consumers after build.
|
| setNullable | | public void setNullable()(Code) | | |
| setRepeatable | | public void setRepeatable()(Code) | | |
| setStrategyFactoryMethod | | public void setStrategyFactoryMethod(StrategyFactoryMethod strategyFactoryMethod)(Code) | | Passes the factory for Strategy objects to all contained ConsumerAlternatives.
|
| subtract | | public void subtract(Consumer constraint)(Code) | | Passed Consumer will constrain every character of this consumer.
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| subtract | | public void subtract(Reference constraint)(Code) | | Passed reference will constrain every character of this consumer.
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| toString | | public String toString()(Code) | | String representation of consumer: hashcode, sequence and constraints.
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| toStringBase | | protected String toStringBase()(Code) | | Returns the base string for toString() method.
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