org.matheclipse.core.patternmatching

Class PatternMatcher

java.lang.Object

org.matheclipse.core.patternmatching.IPatternMatcher

org.matheclipse.core.patternmatching.PatternMatcher

All Implemented Interfaces:

java.io.Externalizable, java.io.Serializable, java.lang.Cloneable, java.lang.Comparable<IPatternMatcher>, java.util.function.Predicate<IExpr>

Direct Known Subclasses:

AbstractPatternMatcherMethod, PatternMatcherAndEvaluator, PatternMatcherAndInvoker

public class PatternMatcher
extends IPatternMatcher
implements java.io.Externalizable

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
class	PatternMatcher.OrderlessMatcher Matches an IAST with header attribute Orderless .
protected class	PatternMatcher.StackMatcher Manage a stack of pairs of expressions, which have to match each other

Field Summary

Fields

Modifier and Type	Field and Description
protected IExpr	fPatternCondition Additional condition for pattern-matching maybe null
protected PatternMap	fPatternMap A map from a pattern to a possibly found value during pattern-matching.
protected int	fPriority priority of this matcher

Fields inherited from class org.matheclipse.core.patternmatching.IPatternMatcher

fLhsPatternExpr

Constructor Summary

Constructors

Constructor and Description
PatternMatcher() Needed for serialization
PatternMatcher(IExpr patternExpr)

Method Summary

Modifier and Type	Method and Description
boolean	checkCondition() Check if the condition for this pattern matcher evaluates to true.
boolean	checkRHSCondition(EvalEngine engine) Check if the condition for the right-hand-sides Module[] or Condition[] expressions evaluates to true.
java.lang.Object	clone()
int	compareTo(IPatternMatcher o)
boolean	equals(java.lang.Object obj)
static boolean	equivalent(IExpr patternExpr1, IExpr patternExpr2, PatternMap pm1, PatternMap pm2) Check if the two left-hand-side pattern expressions are equivalent.
int	equivalent(IPatternMatcher obj)
IExpr	eval(IExpr leftHandSide) Match the given left-hand-side and return an evaluated expression
protected IExpr	evalAST(IAST lhsPatternAST, IAST lhsEvalAST, IExpr rhsExpr, PatternMatcher.StackMatcher stackMatcher)
static IExpr	evalLeftHandSide(IAST leftHandSide)
static IExpr	evalLeftHandSide(IAST leftHandSide, EvalEngine engine) Transform the ast recursively, according to the attributes Flat, HoldAll, HoldFirst, HoldRest, Orderless for the left-hand-side of a Set[] or SetDelayed[] expression.
IExpr	getCondition() Get the additional condition for pattern-matching
void	getPatterns(java.util.List<IExpr> resultList, IExpr pExpr) Returns the matched pattern in the order they appear in the pExpr
protected IExpr	getPatternValue0() Return the matched value for index 0 if possisble.
int	getPriority() Get the priority of this pattern-matcher.
int	hashCode()
protected void	init(IExpr patternExpr)
boolean	isRuleWithoutPatterns() Returns true if the given expression contains no patterns
protected void	logConditionFalse(IExpr lhsEvalAST, IExpr lhsPatternAST, IExpr rhsAST)
protected boolean	matchAST(IAST lhsPatternAST, IExpr lhsEvalExpr, PatternMatcher.StackMatcher stackMatcher)
protected boolean	matchExpr(IExpr lhsPatternExpr, IExpr lhsEvalExpr) Checks if the two expressions match each other
protected boolean	matchExpr(IExpr lhsPatternExpr, IExpr lhsEvalExpr, PatternMatcher.StackMatcher stackMatcher) Checks if the two expressions match each other
void	readExternal(java.io.ObjectInput objectInput)
void	setCondition(IExpr condition) Sets an additional evaluation-condition for pattern-matching
boolean	test(IExpr leftHandSide) Start pattern matching.
void	writeExternal(java.io.ObjectOutput objectOutput)

Methods inherited from class org.matheclipse.core.patternmatching.IPatternMatcher

getLHS, getRHS

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface java.util.function.Predicate

and, isEqual, negate, or

Field Detail

fPriority

protected transient int fPriority

priority of this matcher

fPatternCondition

protected IExpr fPatternCondition

Additional condition for pattern-matching maybe null

fPatternMap

protected transient PatternMap fPatternMap

A map from a pattern to a possibly found value during pattern-matching. Will be set to null if the left-hand-side pattern expression contains no pattern.

Constructor Detail

PatternMatcher

public PatternMatcher()

Needed for serialization

Parameters:

patternExpr -

PatternMatcher

public PatternMatcher(IExpr patternExpr)

Method Detail

init

protected final void init(IExpr patternExpr)

checkRHSCondition

public boolean checkRHSCondition(EvalEngine engine)

Check if the condition for the right-hand-sides Module[] or Condition[] expressions evaluates to true. Override it in subclasses.

Returns:

true

See Also:

PatternMatcherAndEvaluator.checkRHSCondition(EvalEngine)

checkCondition

public boolean checkCondition()

Check if the condition for this pattern matcher evaluates to true.

equivalent

public static boolean equivalent(IExpr patternExpr1,
                                 IExpr patternExpr2,
                                 PatternMap pm1,
                                 PatternMap pm2)

Check if the two left-hand-side pattern expressions are equivalent. (i.e. f[x_,y_] is equivalent to f[a_,b_] )

Parameters:

patternExpr1 -

patternExpr2 -

pm1 -

pm2 -

Returns:

getPatterns

public void getPatterns(java.util.List<IExpr> resultList,
                        IExpr pExpr)

Returns the matched pattern in the order they appear in the pExpr

Specified by:

getPatterns in class IPatternMatcher

Parameters:

resultList -

pExpr -

getPatternValue0

protected IExpr getPatternValue0()

Return the matched value for index 0 if possisble.

Returns:

null if no matched expression exists

getPriority

public int getPriority()

Get the priority of this pattern-matcher. Lower values have higher priorities.

Specified by:

getPriority in class IPatternMatcher

Returns:

the priority

isRuleWithoutPatterns

public final boolean isRuleWithoutPatterns()

Returns true if the given expression contains no patterns

Specified by:

isRuleWithoutPatterns in class IPatternMatcher

Returns:

test

public boolean test(IExpr leftHandSide)

Description copied from class: IPatternMatcher

Start pattern matching.

Specified by:

test in interface java.util.function.Predicate<IExpr>

Specified by:

test in class IPatternMatcher

Returns:

true if the expr matches the pattern-matchings left-hand-side expression.

matchExpr

protected boolean matchExpr(IExpr lhsPatternExpr,
                            IExpr lhsEvalExpr)

Checks if the two expressions match each other

Returns:

matchExpr

protected boolean matchExpr(IExpr lhsPatternExpr,
                            IExpr lhsEvalExpr,
                            PatternMatcher.StackMatcher stackMatcher)

Checks if the two expressions match each other

Returns:

matchAST

protected boolean matchAST(IAST lhsPatternAST,
                           IExpr lhsEvalExpr,
                           PatternMatcher.StackMatcher stackMatcher)

evalAST

protected IExpr evalAST(IAST lhsPatternAST,
                        IAST lhsEvalAST,
                        IExpr rhsExpr,
                        PatternMatcher.StackMatcher stackMatcher)

Parameters:

lhsPatternAST -

lhsEvalAST -

rhsExpr -

stackMatcher -

Returns:

F.NIL if no match was found.

logConditionFalse

protected void logConditionFalse(IExpr lhsEvalAST,
                                 IExpr lhsPatternAST,
                                 IExpr rhsAST)

eval

public IExpr eval(IExpr leftHandSide)

Match the given left-hand-side and return an evaluated expression

Specified by:

eval in class IPatternMatcher

Parameters:

leftHandSide - left-hand-side expression

Returns:

F.NIL if the match wasn't successful, the evaluated expression otherwise.

equals

public boolean equals(java.lang.Object obj)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

clone

public java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Overrides:

clone in class IPatternMatcher

Throws:

java.lang.CloneNotSupportedException

getCondition

public IExpr getCondition()

Get the additional condition for pattern-matching

setCondition

public void setCondition(IExpr condition)

Sets an additional evaluation-condition for pattern-matching

evalLeftHandSide

public static IExpr evalLeftHandSide(IAST leftHandSide,
                                     EvalEngine engine)

Transform the ast recursively, according to the attributes Flat, HoldAll, HoldFirst, HoldRest, Orderless for the left-hand-side of a Set[] or SetDelayed[] expression. Delegates to EvalEngine#evalSetAttributes()method

Parameters:

ast -

Returns:

F.NIL if evaluation is not possible

See Also:

org.matheclipse.core.eval.EvalEngine#evalSetAttributes()

evalLeftHandSide

public static IExpr evalLeftHandSide(IAST leftHandSide)

compareTo

public int compareTo(IPatternMatcher o)

Specified by:

compareTo in interface java.lang.Comparable<IPatternMatcher>

equivalent

public int equivalent(IPatternMatcher obj)

writeExternal

public void writeExternal(java.io.ObjectOutput objectOutput)
                   throws java.io.IOException

Specified by:

writeExternal in interface java.io.Externalizable

Throws:

java.io.IOException

readExternal

public void readExternal(java.io.ObjectInput objectInput)
                  throws java.io.IOException,
                         java.lang.ClassNotFoundException

Specified by:

readExternal in interface java.io.Externalizable

Throws:

java.io.IOException

java.lang.ClassNotFoundException