1 "{ Package: 'stx:goodies/xmlsuite/xpath' }"

     2 

     3 "{ NameSpace: XMLv2 }"

     4 

     5 Object subclass:#XPathExpressionOptimizer

     6 	instanceVariableNames:'xpathExpression'

     7 	classVariableNames:''

     8 	poolDictionaries:''

     9 	category:'XML Suite-XPath'

    10 !

    11 

    12 

    13 !XPathExpressionOptimizer class methodsFor:'optimizer'!

    14 

    15 optimize: xpathExpression

    16 

    17     ^self new

    18         xpathExpression: xpathExpression;

    19         optimize;

    20         xpathExpression

    21 

    22     "Created: / 21-11-2007 / 10:43:43 / janfrog"

    23 ! !

    24 

    25 !XPathExpressionOptimizer methodsFor:'accessing'!

    26 

    27 xpathExpression

    28     ^ xpathExpression

    29 

    30     "Created: / 21-11-2007 / 10:43:48 / janfrog"

    31 !

    32 

    33 xpathExpression:something

    34     xpathExpression := something.

    35 

    36     "Created: / 21-11-2007 / 10:43:48 / janfrog"

    37 ! !

    38 

    39 !XPathExpressionOptimizer methodsFor:'optimizing'!

    40 

    41 optimize

    42 

    43     self optimizeDescendantOrSelf

    44 

    45     "Created: / 21-11-2007 / 10:45:04 / janfrog"

    46 !

    47 

    48 optimizeDescendantOrSelf

    49 

    50     | newXPathExpression locationStepIndex |

    51     xpathExpression size < 1 ifTrue:[^self].

    52     newXPathExpression := XPathExpression new absolute: xpathExpression absolute.

    53     locationStepIndex := 1.

    54 

    55     [locationStepIndex < xpathExpression size] whileTrue:

    56         [| currentLocationStep nextLocationStep |

    57         currentLocationStep := xpathExpression at:locationStepIndex.

    58         nextLocationStep := xpathExpression at:locationStepIndex + 1.

    59         (currentLocationStep isDescendantOrSelfWithAnyKindTestStepAndWithoutPredicates

    60             and:[nextLocationStep isChildWithNameTestStep])

    61                 ifTrue:

    62                     [newXPathExpression add:

    63                         (XPathLocationStep new

    64                             axis: XPathAxisDescendantOrSelf new;

    65                             nodeTest: nextLocationStep nodeTest;

    66                             predicates: nextLocationStep predicates).

    67                     locationStepIndex := locationStepIndex + 1]

    68                 ifFalse:

    69                     [newXPathExpression

    70                         add: currentLocationStep].

    71         locationStepIndex := locationStepIndex + 1].

    72     locationStepIndex = xpathExpression size ifTrue:

    73         [newXPathExpression add:xpathExpression last].

    74     xpathExpression := newXPathExpression

    75 

    76     "Created: / 21-11-2007 / 11:02:49 / janfrog"

    77 ! !

    78 

    79 !XPathExpressionOptimizer class methodsFor:'documentation'!

    80 

    81 version

    82     ^ '$Header: /opt/data/cvs/stx/goodies/xmlsuite/xpath/XMLv2__XPathExpressionOptimizer.st,v 1.1 2007-11-22 21:47:19 vranyj1 Exp $'

    83 ! !