ua.gradsoft.termware
Class TermSystem

java.lang.Object
  ua.gradsoft.termware.TermSystem

public class TermSystem
extends Object

TermSystem is set < rules,facts,strategy,env > where

• rules - set of rewriting rules.
• strategy - strategy for applying of this rules.
• facts - deductive database of facts.
• env - environment for input/output.

The main sence of term system - reduce terms with help of given rules and in given environment by some strategy.

See Also:

IFacts, ITermRewritingStrategy, IEnv

Constructor Summary

TermSystem(ITermRewritingStrategy strategy, IFacts facts)
create new instance of ITermSystem in default TermWare environment.

TermSystem(ITermRewritingStrategy strategy, IFacts facts, TermWareInstance instance)
create new instance of ITermSystem

Method Summary

void	addNormalizer(String termName, ITermTransformer transformer) add normalizer transformer for terms with name termName
void	addRule(String s) add rule s to system.
void	addRule(Term t) add rule t to system with default priority.
Term	apply(String x) synonim of appply(ITermFactory.createParsedTerm(x))
Term	apply(String x, SourceCodeLocation scl) synonim of appply(ITermFactory.createParsedTerm(x,scl))
Term	apply(Term x) apply system to term x.
boolean	checkFact(String s) synonim of checkFact(ITermFactory.createParsedTerm(x))
boolean	checkFact(Term t, TransformationContext ctx) check fact t in associated facts database.
boolean	checkLoggedEntity(String s)
void	clearLoggedEntities()
IEnv	getEnv() get environment for input/output operations.
IFacts	getFacts() get facts base.
TermWareInstance	getInstance() get instance of runtime environment.
Set<String>	getLoggedEntities()
SortedSet<String>	getPatternNames() get patterns for all rules, added to system.
ITermRewritingStrategy	getStrategy() get strategy
boolean	isLoggingMode()
boolean	isReduceFacts() true, if facts are reduced by system before passing to facts database in checkFact and setFact methods.
boolean	isStop()
void	printHelp(PrintStream out) print to output stream name and descriptions of all rules in system.
Term	reduce(Term x) reduce term x
Term	reduce(Term x, TransformationContext ctx) reduce term in given transformation context.
void	setEnv(IEnv env) set environment for input/output operations.
void	setFact(String s) set fact s .
void	setFact(Term t, TransformationContext ctx) set fact t
void	setFacts(IFacts facts) set facts base
void	setLoggedEntities(Collection<String> loggedEntities)
void	setLoggedEntity(String s)
void	setLoggingMode(boolean mode)
void	setReduceFacts(boolean reduceFacts) if set to true, then facts are reduced by system before passing to facts database in checkFact and setFact methods.
void	setStop(boolean stop)
void	unsetLoggedEntity(String s)

Methods inherited from class java.lang.Object

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

Constructor Detail

TermSystem

public TermSystem(ITermRewritingStrategy strategy,
                  IFacts facts,
                  TermWareInstance instance)

create new instance of ITermSystem

Parameters:

strategy - - strategy

facts - - database of facts

instance - - instance of TermWare environment.

TermSystem

public TermSystem(ITermRewritingStrategy strategy,
                  IFacts facts)

create new instance of ITermSystem in default TermWare environment.

Parameters:

strategy - - strategy

facts - - database of facts

Method Detail

apply

public Term apply(Term x)

apply system to term x. (try to reduce, on error return NIL)

Parameters:

x - term to reduce

Returns:

reduced term, or nil if reduce was failed.

apply

public final Term apply(String x)

synonim of appply(ITermFactory.createParsedTerm(x))

Parameters:

x - string, with term to reduce.

Returns:

reduced Term, or NIL if parsing was failed.

apply

public final Term apply(String x,
                        SourceCodeLocation scl)

synonim of appply(ITermFactory.createParsedTerm(x,scl))

Parameters:

x - string, with term to reduce.

scl - source code location of x.

Returns:

reduced Term, or NIL if parsing was failed.

checkFact

public boolean checkFact(Term t,
                         TransformationContext ctx)
                  throws TermWareException

check fact t in associated facts database. (after reducing of t, if ReduceFacts property set to true).

Parameters:

t - fact to check.

ctx - transformation context of system.

Returns:

true if fact t is checked, false otherwise.

Throws:

TermWareException

See Also:

isReduceFacts(), setReduceFacts(boolean), setFact(ua.gradsoft.termware.Term, ua.gradsoft.termware.TransformationContext)

checkFact

public boolean checkFact(String s)
                  throws TermWareException

synonim of checkFact(ITermFactory.createParsedTerm(x))

Parameters:

s - - sring with facts to reduce.

Returns:

true if fact is checked.

Throws:

TermWareException

setFact

public void setFact(Term t,
                    TransformationContext ctx)
             throws TermWareException

set fact t

Throws:

TermWareException

setFact

public final void setFact(String s)
                   throws TermWareException

set fact s .

Throws:

TermWareException

isReduceFacts

public boolean isReduceFacts()

true, if facts are reduced by system before passing to facts database in checkFact and setFact methods.

See Also:

setReduceFacts(boolean)

setReduceFacts

public void setReduceFacts(boolean reduceFacts)

if set to true, then facts are reduced by system before passing to facts database in checkFact and setFact methods. otherwise, facts terms are passed to facts database directly.

See Also:

isReduceFacts(), checkFact(ua.gradsoft.termware.Term, ua.gradsoft.termware.TransformationContext), setFact(ua.gradsoft.termware.Term, ua.gradsoft.termware.TransformationContext)

addRule

public void addRule(Term t)
             throws TermWareException

add rule t to system with default priority.

Throws:

TermWareException

addRule

public final void addRule(String s)
                   throws TermWareException

add rule s to system. alias for addRule(ITermFactory.createParsedTerm(s));

Throws:

TermWareException

addNormalizer

public void addNormalizer(String termName,
                          ITermTransformer transformer)
                   throws TermWareException

add normalizer transformer for terms with name termName

Throws:

TermWareException

reduce

public Term reduce(Term x)
            throws TermWareException

reduce term x

Throws:

TermWareException

reduce

public Term reduce(Term x,
                   TransformationContext ctx)
            throws TermWareException

reduce term in given transformation context. (This method used for shared transformation context between many systems, as implementation of apply)

Throws:

TermWareException

getEnv

public final IEnv getEnv()

get environment for input/output operations. If one was not set, than environment from TermWare instance is returned.

Returns:

i/o environment.

See Also:

IEnv, TermWareInstance.getEnv(), setEnv(ua.gradsoft.termware.IEnv)

setEnv

public final void setEnv(IEnv env)

set environment for input/output operations.

See Also:

IEnv, TermWareInstance.getEnv(), getEnv()

isStop

public final boolean isStop()

setStop

public final void setStop(boolean stop)

isLoggingMode

public final boolean isLoggingMode()

setLoggingMode

public final void setLoggingMode(boolean mode)

checkLoggedEntity

public final boolean checkLoggedEntity(String s)

setLoggedEntity

public final void setLoggedEntity(String s)

unsetLoggedEntity

public final void unsetLoggedEntity(String s)

getLoggedEntities

public final Set<String> getLoggedEntities()

setLoggedEntities

public final void setLoggedEntities(Collection<String> loggedEntities)

clearLoggedEntities

public final void clearLoggedEntities()

getStrategy

public final ITermRewritingStrategy getStrategy()

get strategy

Returns:

strategy of the system

getFacts

public final IFacts getFacts()

get facts base.

Returns:

facts of the system.

setFacts

public void setFacts(IFacts facts)

set facts base

Parameters:

facts - - new facts to set.

getInstance

public final TermWareInstance getInstance()

get instance of runtime environment.

Returns:

instance of TermWare runtime.

printHelp

public void printHelp(PrintStream out)

print to output stream name and descriptions of all rules in system.

Parameters:

out - - where we print help messages.

getPatternNames

public SortedSet<String> getPatternNames()

get patterns for all rules, added to system.

Returns:

sorted set of all patterns in system